Posts on Bald Engineer

Replacing Electrolytic Capacitors | VCF Midwest 2025 Talk

Sun, 14 Sep 2025 02:17:41 +0000

Slides PDF: Electrolytics are Ticking Time Bombs
Bit Preserve: GitHub Repo with Vintage Computer Schematics in KiCad
Bald Engineer’s Capacitor Video Playlist
TRS 80 Model 100 Cap Replacement Spreadsheet (add a pitch column!)

Talk for Vintage Computer Festival Midwest #20 (2025).

Can Polymer Capacitors Replace MLCCs?

Wed, 16 Apr 2025 16:45:32 +0000

Multi-layer ceramic capacitors (MLCCs) are so ubiquitous that you see them on almost every printed circuit board. Engineers and supply chain managers often ask whether polymer electrolytic capacitors can replace MLCCs. The replacement could be because of availability, or an application cannot tolerate the extreme capacitance loss with MLCC’s DC Bias Effect. This video demonstrates what happens when you replace MLCCs with Polymer Tantalum (KO-CAP) capacitors.

Exploring DIY PCB Assembly versus Turnkey Services with MacroFab and Bald SENSE

Tue, 27 Aug 2024 14:56:59 +0000

Experience comparing DIY and Turnkey PCB assembly with the Bald SENSE project. This journey started almost four years ago. Thanks to a collaboration with MacroFab, I am finally collecting valuable environmental data with my custom Feather Wing.

A big thank you to MacroFab for manufacturing the boards and sponsoring the video. I also want to thank Unexpected Maker for their noteworthy contribution to the FeatherS3 microcontroller boards, which played an essential role in the video.

Hands-on with PicoScope 7

Fri, 26 Jul 2024 15:16:47 +0000

I dive into Pico Technology’s latest PicoScope oscilloscope software, PicoScope 7. Using a PicoScope 2000A (from the element14 Community), James walks through key measurements and demonstrations using the built-in arbitrary waveform generator. He explores new functionalities in PicoScope 7, such as the improved UI, a unique feature called DeepMeasure, and decoding I3C traffic.

I have been using the Pico Technology PicoScope 2000A for years. (Here is my older review!) It is an entry-level oscilloscope with 10 MHz bandwidth, 100 megasamples per second sample rate, and 8 kilosample of acquisition memory. Since it is USB-based, it has companion software running on Windows, macOS, and Linux.

Python to set 8th bit in ASCII String

Sun, 30 Jun 2024 17:18:31 +0000

The Apple II’s ROM has the 8th bit set for all of its ASCII strings. This convention makes it difficult to search the ROM for hex strings quickly. This Python script takes an ASCII string and returns the HEX string with (and without) the 8th bit set.

Python Code

input_string = "Mega IIe"

def string_to_hex_ascii(input_string, set_bit_8=False):
 hex_values = []
 for char in input_string:
 # Get the ASCII value of the character ord() and convert it string
 # representing the hex() value
 #
 # [2:] strips the '0x'

 if (set_bit_8):
 hex_value = (hex(ord(char) | 0x80)).upper() # for Apple II, awww
 else:
 hex_value = (hex(ord(char))).upper()

 hex_values.append(hex_value[2:])

 return hex_values

def print_list_with_spaces(input_list):
 # Join the list elements into a single string with spaces in between
 result = ' '.join(map(str, input_list))
 print(result)

def print_og_string_formatted(input_string):
 result = ' '.join(input_string)
 print(result)

# Remind user of string
print("Og : ", end='')
print_og_string_formatted(input_string)

# As-is ASCII in Hex
hex_values_raw = string_to_hex_ascii(input_string)
print("Raw : ", end='')
print_list_with_spaces(hex_values_raw)

# Hex with 8th bit set
hex_values_8bit = string_to_hex_ascii(input_string, True)
print("8bit: ", end='')
print_list_with_spaces(hex_values_8bit)

Disclaimer: I used ChatGPT to generate an initial script for converting an ASCII string to a list of hex values. Then, I wrote the rest.

STOP! Using the Wrong Capacitors | Teardown 2024

Thu, 20 Jun 2024 02:04:11 +0000

Learn more about Teardown 2024

Google Slides

Download Slides (PDF)

B&K Precision DAS60 Hands-On

Wed, 05 Jun 2024 16:42:26 +0000

The B&K Precision DAS60 is a data recorder. It features 6 wide-range voltage inputs, 16 digital channels, and RTD thermal sensor inputs and comes in a small compact form factor. In this video, I show what it can do.

The DAS60 is designed for lab and fieldwork. Its built-in battery means you can deploy it in a facility and let it log data. It has built-in ethernet and support for generic Wi-Fi dongles. The computer runs Windows CE and has RealVNC pre-installed. This combination lets you connect remotely to configure the instrument, check its status, or review recorded data.

Retro Repairs RoundUp Appearance

Mon, 03 Jun 2024 23:35:11 +0000

The Retro Repairs RoundUp crew invited me to be a guest on episode 56 of their livestream. As their name implies, they discuss retro computers and, in many streams, how to repair them. We mostly discussed the Mega IIe project. Sean was another guest who talked about KansasFest 2024.

KansasFest is an Apple II conference. This year, it moved its venue to Springfield, Illinois. The name and the location might seem confusing; however, it was long held in Missouri. So, it is a case of the name sticking for historical reasons.

Mega IIe Supercon 2023 Talk is now Live!

Wed, 15 May 2024 13:06:13 +0000

I must extend a big “Thank You!” to Lewin Day at Hackaday for this excellent Mega IIe write-up. Accompanying the post is an archived recording of my Supercon 2023 talk. That talk is where I gave a complete overview of the Mega IIe project and showed off the final case design for the first time! This project is where I took the Mega-II chip out of an Apple IIGS and built a fully compatible Apple IIe around it—something that not even Apple ever did!

NXP's MCX FRDM Board Hands-On

Wed, 01 May 2024 16:59:43 +0000

Check out NXP’s latest microcontroller boards. These boards of their new MCX-A and MCX-N microcontrollers. The form factor is what NXP calls Freedom (FRDM.)

The MCX line of microcontrollers, each with its unique set of features, caters to a wide range of projects. The MCX-A, a general-purpose microcontroller, is ideal for entry-level projects, while the high-performance MCX-N is designed for advanced AI/machine learning tasks. NXP recently started shipping the MCX-N, adding to its versatility and appeal.

WiFi-Enabled LED detector tells me when my Dehumidifier is Full!

Fri, 12 Apr 2024 23:40:13 +0000

I created a Wi-Fi-enabled LED Detector using Nordic’s nRF7002 Design Kit (DK). Using this box, I can detect when LEDs on appliances, like my lab’s dehumidifier, are on. In other words, my non-IoT tool can send me messages over the Internet now! And, because the nRF7002 has a dual-band Wi-Fi antenna, it does so on my 5 GHz network.

I ran into a number of issues with this project, and I expected that. Except for the RF part of the design, which works fine! Links to the design files are available on the post on the element14 Community.

From MLCC to Polymer: Unlocking Capacitor Impedance Plot Secrets

Tue, 02 Apr 2024 16:41:10 +0000

April 17, 2024, at 1:00 pm CDT

Capacitors are deceptively complex devices. It is why I love talking about them so much! Hioki USA loaned me an LCR Meter that works as an Impedance Analyzer to try out some measurements. As a result, I noted a few things that might catch someone off guard if they have never attempted to characterize capacitors.

For example, many of us know about the MLCC DC Voltage Coefficient. However, do you know how to evaluate whether your parts lose 20 or 80% of their capacitance? Or, what considerations do you need to make when measuring a polymer electrolytic versus a film capacitor?

Measuring Apple II CPU's Glitchy Clock

Wed, 20 Mar 2024 17:58:51 +0000

The Apple II’s CPU clock has jitter or a glitch. This issue is not new—it has been present since its original design in 1977! Bald Engineer uses an oscilloscope to show how often the glitch occurs and how to correlate that jitter to its source—which is useful when you are not testing 40-year-old devices. The device under test (DUT) in this video is the Mega IIe project. It’s a fully compatible Apple IIe built around the Mega II chip.

Picking I2C Pull-Up Resistors (Correctly)

Thu, 07 Mar 2024 13:22:00 +0000

A long time ago, I made a video suggesting math was unnecessary to determine proper pull-up resistor values. Like most generalized statements, that suggestion is not always true. For example, in data buses like I2C, speeds like 400 kHz and 1 MHz are common. At those speeds, the pull-up resistor and the bus capacitance form an RC filter that fundamentally limits the data transmission speed. Or. It limits the range of pull-up resistor values. In this Workbench Wednesdays video, I show how to estimate I2C bus capacitance, measure that capacitance, and pick pull-up resistor values.

A Vintage Computing Adventure (Mega IIe)

Wed, 06 Mar 2024 04:35:16 +0000

Your browser does not support the video element.

Parker and Stephen invited me back to discuss the Mega IIe project on the MacroFab Circuit Break podcast. This discussion was far more casual than my past appearances. It was the first time I didn’t feel the need to do any prep work for their excellent questions!

We talked through the overall experience of rev 1, rev 2, and rev 3. I appreciated the chance to talk about my motivations behind the Mega IIe project, why I like the Apple II platform so much, and getting to nerd out with Parker on analog video signal concepts.

Eight KiCad 8 features I like

Mon, 26 Feb 2024 16:23:38 +0000

KiCad 8 just dropped. Here’s an AddOhms video covering eight must-try features! The February 2024 release brings a whole host of new stuff to the Schematic editor. However, the PCB editor, CLI, and Simulation tools also received attention. (There are something like 900 closed issues for the 8.0.0 Milestone!) Which of these is your favorite?

In the video, I cover:

Property Manager Panel (is now everywhere)
A fix for Symbol pin or wire end off connection grid!
Easily access alternate pin functions (on symbols with them)
Pin Helpers save time
Edit Power Symbols (instead of creating new library parts)
Net Navigator and Search panels help with large schematics
Improved custom polygon tools in PCB
(Combined) Teardrop support and Length-Tuning improvements

This AddOhms post covers my top 8 in more detail. Or, you could just watch the video!

Accessing USB instruments with pyvisa on Linux

Tue, 13 Feb 2024 21:27:23 +0000

USB-Based instruments that do not appear to the host as a virtual com port (VCP) usually use libusb for communication. The pyvisa-py driver for pyvisa can communicate with these instruments. However, you must first create a udev rule (and possibly a user group.)

If you see the device in lsusb, but not the pyvisa ResourceManager, you need to add (or modify a udev rule):

# backup 99-com.rules (if it exists)
cp /etc/udev/rules.d/99-com.rules /etc/udev/rules.d/99-com.rules.BAK

# (create and) edit the file
nano /etc/udev/rules.d/99-com.rules

# Add the following line
SUBSYSTEM=="usb", MODE="0666", GROUP="usbusers"

# create a usbusers group
sudo groupadd usbusers

# add your account to the new group
sudo usermod -a -G usbusers USERNAME

# restart udev
/etc/init.d/udev restart
(Although, you are probably better off rebooting.)

nRF7002 DK vs EK vs EB Hands-On

Thu, 01 Feb 2024 13:53:00 +0000

In August 2022, Nordic Semiconductor announced its first Wi-Fi product. The nRF7002 is a dual-band (2.4 and 5 GHz) Wi-Fi 6 compatible companion IC. It does not have a general-purpose microcontroller built-in. Instead, Nordic intends for you to combine it with another microcontroller, like one of their nRF52 or nRF53-series system on chip (SoC).

Nordic and the element14 Community sent me an nRF7002 Development Kit (DK), Evaluation Kit (EK), and some nRF7002 QFNs. I reviewed the nRF70 variants in this video and looked at the various boards. As the thumbnail suggests, I connected the Wi-FI transceiver to a FPC1500 spectrum analyzer.

RP2040 Debug and Turn-On Tips

Wed, 31 Jan 2024 17:35:18 +0000

During the component shortage, I got to know Raspberry Pi’s RP2040 microcontroller. It is a dual-core Arm Cortex-M0+ with about 262 kilobytes of RAM. The feature I like most is the programmable IO pins. These are small state machines that run independently of the Arm cores. They allow for some clever tricks. For example, I used them extensively on the Mega IIe project.

This video was supposed to be a project I thought of during the Mega IIe. I call it a state-mode logic analyzer. However, it took me several days to turn on and debug four boards. Time ran out, so I focused the video on debugging custom RP2040-based boards. These are all lessons I have learned from this project, plus about another dozen RP2040 boards I have built over the past couple of years.

Mega IIe Picture Album

Wed, 20 Dec 2023 13:36:00 +0000

Most of these pictures from the Mega IIe project did not make it into a video or talk. There were many “behind the scenes” style shots. Some of the pictures have titles and descriptions. I work on them when I have free time. Let me know your favorite!

https://www.flickr.com/photos/cmiyc/albums/72177720312911955/

Mega IIe Album on Flickr

Navigate one picture at a time with the left/right arrows, or follow the link below to see the full album.

Use Your Scope! | Unnamed Reverse Engineering Podcast

Tue, 19 Dec 2023 19:34:28 +0000

Alvaro and Jen invited me to discuss the reverse engineering aspect of the Mega IIe project on the Unnamed Reverse Engineering Podcast. We focused on some of the finer details about the Mega-II chip’s operation. The discussion followed many rabbit holes. (Totally my fault and not theirs!)

We also talked a little bit about how to (not) identify unlabeled capacitors when reverse engineering hardware. The to-long-did-not-read (tldr;) is that for multilayer ceramic capacitors (MLCCs), there isn’t much you can do. You can use an LCR to determine the capacitance, but there isn’t a non-destructive way to determine the rated voltage. I did offer one suggestion related to waterfall tables.

Mega IIe Supercon Links

Sat, 04 Nov 2023 20:56:28 +0000

These links accompany the Mega IIe presentation at Supercon 2023.

Slides

PDF of the Slides (23mb)

Thank You

Hamvention 2023 Pick Ups

Fri, 26 May 2023 18:49:52 +0000

The Dayton Amateur Radio Association (DARA) hosted Hamvention 2023 in Xenia, Ohio, on the weekend of May 19th. This annual event is the largest gathering of amateur radio operators. Sprawled across the Greene County Fairgrounds and Expo Center are commercial vendors selling gear or services, educational talks, license exams, and a massive flea market.

Of the various activities, my favorite is to wander around the dozens of rows of people selling items in the flea market. For some people, this is the only reason even to attend! Here are a few of the things I picked up and plan to do some work on.

Difference between flux (for soldering)

Wed, 17 Aug 2022 13:17:00 +0000

Often I hear this question: “how can I get better solder joints?” Without looking at anything they are doing, I already know that they could be using more flux. Or, as I point out in this video, perhaps the correct type of flux!

Flux removes oxide layers, gets contaminants out of the way, and makes for better solder joints. But there are so many different types of flux and even more ways to apply it.

Oscilloscope Trigger Primer

Thu, 04 Aug 2022 17:54:34 +0000

A powerful, but an underused feature of digital oscilloscopes is the trigger circuit. Learn from James how to use an oscilloscope’s trigger to find glitches, measure pulse widths, see transients, and stabilize a scope’s screen. This video explains the difference between Auto and Normal sweep modes, shows how to use a Pulse Width trigger, and explains how to use Hold-Off.

How to Profile Battery Usage for IoT Devices

Sat, 25 Jun 2022 13:08:00 +0000

When running on a battery, it is important to know what parts of your circuit draw the most current. Profiling is a process where you look at sections of code or interactions with hardware to see how much power each requires. In this video, James shows four tools (and their tradeoffs) when profiling IoT or Edge Machine Learning devices. See if it makes more sense for you to use a Digital Multimeter (DMM), Power Supply with history graphs, an oscilloscope

Do ALL Scope Probes Need Ground?

Fri, 24 Jun 2022 13:05:00 +0000

When connecting multiple oscilloscope probes to a circuit, does each probe need to connect to ground?

The short answer is yes!

Why? The long answer is kind because of the ground loop. Remember, a circuit needs a closed path. And while on DC circuits we may rarely think about the distance of that path, it absolutely matters when there is an AC or frequency component.

When you do not connect each probe’s ground, the signal path because enormous since it must connect to the circuit’s ground through another probe. (See the animation in the video above.)

How Oscilloscope Acquisition Modes Work

Thu, 23 Jun 2022 13:38:00 +0000

Every digital oscilloscope I have ever used has a menu or dialog for “acquisition modes.” And depending on the current settings, changing that acquisition mode does not seem to have an effect on the signal. Or sometimes, changing to something like Average mode can completely destroy your measurements.

It turns out, that the analog-to-digital converters in digital oscilloscopes can do more than just “sample” the data. Well, the ADCs just samples. The controller behind the ADC offers modes like Peak Detect and Average and High-Resolution.

Hands-On with B&K Precision 9140 Power Supply | Workbench Wednesdays #53

Wed, 22 Jun 2022 15:36:22 +0000

Bench power supplies are an essential piece of test equipment gear. And like most test gear, they have a wide range of capabilities. For example, the B&K Precision 9140 is a triple output supply that can output up to 300 watts. But, the basic capability isn’t what interested me about the supply. Instead, it was advanced features like rear panel triggers, adjustable slew rate, and built-in sequencing.

The element14 Community arranged for a B&K Precision 9140 power supply to be sent to me for a hands-on overview of those features.

KiCad: Connect Polygon Lines

Thu, 09 Jun 2022 16:55:58 +0000

fix broken polygons in kicad

In KiCad 6, using the Polygon tool makes square boards easy. Just select the Edge.Cuts layer, then the polygon tool, and draw a square. However, if you want custom shapes, then you need to connect multiple line segments together.

If you are not careful, the segments will not connect and you might get one of two errors. The first comes when you run DRC.

Three Tips to Improve Your Soldering | Workbench Wednesdays #52

Fri, 11 Mar 2022 00:25:00 +0000

Using a Metcal GT120, we look at three ways to improve your soldering skills. Using flux, setting a correct temperature, and selecting the proper tip all result in better solder joints. See how well the GT120 works while learning (or reviewing) some basics to improve your soldering skills.

This episode was sponsored by Metcal.

How to Measure Ripple Voltage on a Switch-Mode Power Supply | Workbench Wednesdays #51

Tue, 01 Mar 2022 00:23:00 +0000

Measuring a switch-mode power supply (SMPS) with a DMM might show a stable voltage. But the same DC rail on an oscilloscope can show a completely different story! In this video, learn how to correctly set up an oscilloscope to characterize the noise an SMPS creates in a circuit.

DIY Solder-In Oscilloscope Probes | Workbench Wednesdays #50

Thu, 03 Feb 2022 00:19:00 +0000

When you cannot get an oscilloscope probe into a tight spot, can you just use a piece of wire? Sometimes. When signal integrity matters, you CAN use a low-cost DIY solder-in probe. These probes attenuate the signal and use an oscilloscope’s high-bandwidth 50-ohm input. James shows how to build some solder-in probes when they work and when they do not work in this video.

Special thanks to Shabaz on the element14 community for the guide used here.

Instrument Basics: Vector Network Analyzer (VNA) with PicoVNA | Workbench Wednesdays #49

Wed, 19 Jan 2022 00:15:00 +0000

Vector network analyzers (VNAs) measure how a “network” of components changes the amplitude and phase of signals. By measuring across a wide frequency range, VNAs can create S-Parameters that fully describe the behavior of a circuit. This video uses a PicoVNA 106 to show the basics of what a VNA measures, how they work, and a brief overview of how to use one.

I made a mistake on the explainer graphic for S-parameters. The annoying thing is that I think it was a really good explanation!

Exploring the Digilent Analog Discovery 3000 Pro Series | Workbench Wednesdays #48

Wed, 15 Dec 2021 00:11:00 +0000

Analog Discovery Pro from Digilent comes in a 2-channel (ADP3250) or 4-channel (ADP3450) version. These all-in-one instruments work with a PC over USB or can run entirely standalone.

On the PC the excellent Waveforms software provides virtual instruments like an Oscilloscope, Logic Analyzer, Power Supply, Spectrum Analyzer, Curve Tracer, Network Analyzer, and Impedance Analyzer. Just to name a few. See what this new instrument offers in this hands-on review.

This episode was sponsored by Digilent.

What does Bandwidth mean for Oscilloscopes? | Workbench Wednesdays #47:

Fri, 12 Nov 2021 00:08:00 +0000

Using the Rohde and Schwarz RTH1004 ScopeRider, James talks about oscilloscope bandwidth. In this video, learn what oscilloscope bandwidth is, and what it is not, and see two measurements that help you tell if you are being band-limited by an oscilloscope.

The episode was sponsored by Rohde & Schwarz.

Pros and Cons of Low-Temp Solder Paste | Workbench Wednesdays #46

Mon, 25 Oct 2021 23:03:00 +0000

Low-temperature solder paste makes it easier to reflow-solder and re-work surface mount circuit boards. MG Chemicals offers a Bismuth-based paste that works great from larger passive components to fine pitched packages, like QFN. In this video, learn what solder paste is, what it means for a paste to be “low temperature,” and some things to watch out for when using it.

This episode was sponsored by MG Chemicals.

160 MHz Arbitrary Waveform Generator Review | Workbench Wednesdays #44:

Mon, 20 Sep 2021 22:59:00 +0000

Arbitrary waveform generators can generate almost any waveshape. In this video, see how the MP750290 from Multicomp Pro performs. Its key specs are 160 MHz, 14-bit 1.25 Gigasample per second digital-to-analog converter, 1 million point memory, and over 150 built-in waveforms.

The episode was Sponsored by Multicomp Pro.

The Origins of Delayed Timings on Oscilloscopes | Workbench Wednesdays #43

Tue, 31 Aug 2021 22:57:00 +0000

Almost everyone uses a digital oscilloscope’s zoom features. However, did you know that 40-year-old analog oscilloscopes can do something similar? Delayed time bases on analog scopes sweep twice so that the user can see a slow and fast sweep. In this video, see where “zoom” came from and how engineers accomplished the same measurement back in the day.

Compare Ideal vs. Real Filter with an LCR Meter | Workbench Wednesdays #42

Thu, 05 Aug 2021 22:51:00 +0000

Compare the ideal and measured cut-off frequency for a filter with a handheld LCR meter. Unlike a DMM, these meters apply an AC signal (from 100 Hz to 100 kHz) to determine the reactive component of an inductor, capacitor, or resistor. A simple example here is a low-pass filter. See how the ideal and measured cut-off frequency varies. And THEN, see how it compares between a PCB and a Breadboard.

MC1377 Measurements on Mini Apple IIe Prototype video board

Mon, 02 Aug 2021 16:17:20 +0000

Out of context screenshots are out of context

On the Mini Apple IIe project, I am testing the composite/sync amplifier, which is an MC1377. The composite output looks great, until connecting the output cable to a receiver. It outputs about 2.6 Vpp until loaded with 75 ohms, then it drops to about 400 mVpp. We have replaced most of the passives on the output and have tried 3 different MC1377s. The measurements below are from a known good MC1377 removed from a working Apple IIgs.

How Eaton's Power Defense Circuit Breakers Work | Workbench Wednesdays #41

Thu, 15 Jul 2021 22:45:00 +0000

Circuit breakers make electricity safe in everyday life. The miniature breakers found in your home are relatively simple devices. Commercial units like the Eaton Power Defense with PXR Trip units are found everywhere, even if we do not see them. Learn how a basic circuit breaker works and get some insight into these advanced electronic controlled Circuit Breakers.

In this video, I got to interview Andy at Eaton. He was an interesting person and very knowledgeable about circuit breakers. I had no idea how much technology went into them.

Measurements with an SMU | Workbench Wednesdays #40

Tue, 22 Jun 2021 22:43:00 +0000

Source Measurement Units, or SMUs, combine an accurate power supply, high-power electronic load, and precise digital voltmeter into a signal unit. They are a four-quadrant source. That means they can provide power to a circuit or consume it.

With an SMU you can characterize semiconductor devices (like Diodes), monitor the power consumption of a circuit, or simulate a battery. In this video, see the difference between an SMU and a Power Supply.

Op Amps Without Op Amps | Workbench Wednesdays #39

Tue, 08 Jun 2021 22:35:00 +0000

Okay, technically, this circuit *does* use Op-Amps. However, the ones shown here are integrated into an ATmega128DB microcontroller from Microchip. The DIP package breaks out two operational amplifiers that are controllable entirely by software. Even better, you can program them like they are an Arduino!

Which Oscilloscope Form Factor Is Best For Me? | Workbench Wednesdays #38

Fri, 21 May 2021 22:30:00 +0000

Oscilloscopes are available in many shapes and sizes. After figuring out how much bandwidth you need (or want), the next step is to choose the form factor. Do you go with the traditional bench style? When does it make sense to use a USB-based scope with your PC? And what about these newer tablets or battery-powered oscilloscopes? Learn the difference between them and see which one is best for you.

Desoldering Wick Tips and Tricks with Superwick | Workbench Wednesdays #37

Mon, 12 Apr 2021 22:14:00 +0000

Desoldering braid removes surface solder from a circuit board. It makes reworking PCBs easy and quick. With a few tips and tricks, products like MG Chemical’s Superwick can work like magic. You can remove solder from surface mount parts, wick away excess solder blobs, and repair boards using it. In this video, James shares tips and tricks from the element14 community for using desoldering braid. (Please note: the makers of Superwick, MG Chemicals, sponsored this video)

Essential Logic Families | Workbench Wednesdays #35

Tue, 02 Mar 2021 23:07:00 +0000

Did you know that TTL chips do not output 5 volts? 74LS, 74HC, and 74HCT all have different input and output thresholds. Switching between logic families can be difficult if you are not careful. In this video, learn how different 7400-series logic families compare with input threshold, output voltage, frequency, rise time, and propagation delay.

Check out this TI Application Guide for a great resource on logic families.

Triggering And Decoding Serial Protocols On An Oscilloscope | Workbench Wednesdays #34

Tue, 02 Feb 2021 23:03:00 +0000

Everything with a microcontroller has serial buses in it. Busses like UART, I2C, and SPI are very popular choices. When you have a problem with a sensor that uses one or the bus itself, you can use an oscilloscope or logic analyzer to “decode” the traffic. These decoders convert the 1s and 0s into readable HEX or ASCII characters.

I am not sure how I thought of the “multiple” James idea for the thumbnail. The concept had something to do with “serial,” but I am not sure what.

Measuring A 555 On An Oscilloscope | Workbench Wednesdays #33

Fri, 01 Jan 2021 23:00:00 +0000

The 555 is a very popular chip, and for good reason. It is such a versatile timer. Learn about 555 measurements like how to measure the voltage divider inside the chip and what is going on with the signals in an astable multivibrator (clock) circuit. The key to a 555 circuit is connecting the threshold and trigger pins together. But, until you see the schematic and waveforms it may not be obvious why.

UPS ESR Battery Measurements | Workbench Wednesdays #32:

Tue, 15 Dec 2020 22:57:00 +0000

As batteries age, their ESR goes up. Eventually, they will no longer be serviceable. A battery measurement tool like the Hioki BT3554 lets field service technicians monitor the help of batteries over time. In this video, see how it can be used to measure a live UPS battery.

This episode was sponsored by Hioki.

Essential Consumables for Building Circuits | Workbench Wednesdays #31:

Wed, 18 Nov 2020 22:48:00 +0000

Obviously, you need solder to build most circuits. However, before and after soldering a circuit, there is a bunch of other stuff. In this Workbench Wednesdays episode, James looks at the solder, flux, wick, and cleaning supplies needed when working with electronics. Make sure your lab is stocked with these must-have consumables.

Ceramic Capacitor Voltage Effect | Workbench Wednesdays #30

Wed, 28 Oct 2020 21:46:00 +0000

Ceramic capacitors change capacitance with applied voltage, temperature, and age. They are the most popular electronic component, yet many do not understand what causes this capacitance to change. In this video, James teams up with Murata to see what happens to a simple timer circuit when changing a capacitor from a 1206 case size to a much smaller 0201.

What Active Components Do You Need? | Workbench Wednesday #29

Thu, 08 Oct 2020 21:43:00 +0000

Active components like transistors, BJTs, MOSFETs, and integrated circuits (ICs) make it possible to control circuits. This video explains the must-have NPN and PNP BJTs. For MOSFETs there are a couple of N-Channels and P-Channels to consider. Basic ICs include some digital logic stuff from the 7400-family as well as the venerable 555-timer to have on-hand. We did not forget Op-Amps either. Spoiler: We do not recommend the ua741!

What Passive Components Do You Need? | Workbench Wednesdays #28

Wed, 09 Sep 2020 21:41:00 +0000

Whether you are just getting started in electronics or you have boxes of parts, it is good to know what are the most critical parts to have in your kit. James asked the element 14 community for what they considered to be essential passive components like resistors, capacitors, switches, wires, and even diodes. In this video, he consolidated their puts and explains what to think about when buying these parts for your kit.

Instrument Basics: Logic Probe | Workbench Wednesdays #27

Thu, 13 Aug 2020 21:36:00 +0000

Logic probes are great for debugging 7400 series logic chips and digital circuits. In this video, James makes a counter circuit and debugs each stage as he builds, with a Logic Probe. If you are wondering, “do I need a logic probe” this video shows how one can be used and even answers when you should consider buying one.

How to Measure Sound with a Handheld Meter | Workbench Wednesday #26

Tue, 07 Jul 2020 21:31:00 +0000

One of the loudest pieces of equipment on Bald Engineer’s electronics workbench is the Electronic DC Load. James has finally had it with its noise and decided to swap the fan out. To see (and not just hear) an improvement, he uses a Tenma 72-942 handheld sound meter to compare before and after.

Full notes on element14 community

Measuring a MOSFET's Miller Plateau | Workbench Wednesdays #25

Tue, 07 Jul 2020 21:28:00 +0000

Turning on a MOSFET takes more than knowing the threshold voltage. A special event occurs when a FET turns on, which is called the Miller Plateau. The gate voltage sticks to the threshold voltage while the drain opens up. In this video, James shows how to measure the Miller Capacitance, using an oscilloscope and custom MOSFET test board.

This video came from some measurements I did on a live stream. I had intended to demonstrate something else, but the board I created was such a great demo board for the Miller Effect.

No-Contact Current Measurements | Workbench Wednesday #24

Tue, 05 May 2020 21:25:00 +0000

One of the safest ways to measure current is with a clamp. Clamps do not require you to break the circuit and they safely measure wires with thousands of amps. In this video, we measure DC current in the lab, AC current of a reflow oven controller, and the DC current in a car using a Tenma 72-7226 True RMS Clamp Meter.

This video was the last one I did before moving to a new house / lab.

What that DMM Beep Means - A Continuity Mode Tutorial | Workbench Wednesdays #23

Tue, 28 Apr 2020 21:23:00 +0000

Chances are, you have used the continuity mode of your digital multimeter. But how much do you understand about how it works? In this video, we break down how the mode works, what the beep means, and show examples of how to use it (correctly.) It might seem silly to spend so much time on such a simple mode.

However, I have run across a few posts on the Internet, including the element14 Community where people do not understand continuity mode. Sometimes it is just a lack of experience and sometimes it is a total lack of understanding of what is happening. The biggest mistake, of course, is trying to measure continuity on a powered circuit. That is just a no-go. So in this video, I wanted to show what the meter is actually doing, how it sees different components, and give a couple of real-life examples of how to use it.

Instrument Basics: LCR Meter | Workbench Wednesdays #22

Wed, 01 Apr 2020 23:31:00 +0000

Learn how to use an LCR meter, such as the Tenma 72-10465, to measure reactive components. An LCR meter uses an AC signal at different frequencies to characterize capacitors, inductors, and even resistors. They can also provide impedance measurements. These include phase angle, ESR, quality factor, and dissipation factor.

You can even use the 72-10465 to sort components by their tolerance range.

DMM Half-Digits Explained | Workbench Wednesdays #21

Thu, 05 Mar 2020 22:20:00 +0000

What does it mean for a DMM to have 3.5 digits? How much more accurate is a 5.5 digit multimeter versus a 4.75 digit meter? Many people assume that more digits mean more accuracy. However, these numbers express the precision of the meter, not its accuracy! In this video, learn about a DMM’s accuracy, and what does “half a digit” mean.

As I often do, I messed up the decimals in this one.

Thermal Tools for Circuit Measurements | Workbench Wednesdays

Sun, 23 Feb 2020 17:48:14 +0000

Measuring the effectiveness of a heatsink or the thermal load of a CPU requires thermal test tools. In this episode, learn how an IR Thermometer and a Thermocouple could be used on an electronics workbench. Many multimeters (DMMs) include the ability to measure temperature with a K-type thermocouple. See examples of when each measurement could be used.

Behind the scenes of Thermal Tools Tutorial

Originally intended to use the episode to show how hot the Pi 4 would get. However, by the time I got around to producing it, a new version of Raspbian came out, resolving the temperature issues. To heat up the Pi, I used this toolset from GitHub: XXXXX.

DMM Basics Video Tutorial | Workbench Wednesdays

Sun, 23 Feb 2020 16:47:49 +0000

A multimeter is the go-to-tool for electronics measurements. Knowing how to use it to measure voltage, current, diodes, and transistors can save time (and frustration) while troubleshooting. In this video, James explains how the multimeter works, so that you can understand them better. After watching, you will gain a solid DMM basics understanding.

Behind the scenes of wbw’s DMM Basics

The first Workbench Wednesdays episode covered a pen-style DMM. Back when we were first developing the show, the intent was to be more of a review show and less of a tutorial show. That episode became a mix of both. So we decided to do a straight-up tutorial on DMM basics. Measuring voltage usually has not tripped up too many people, especially on an auto-ranging meter. The main thing to remember with current is to move the red lead back to the voltage input immediately after making a measurement. I touched on continuity briefly but hope to come back and cover that more in the future.

4-Wire Resistance Tutorial | Workbench Wednesdays

Sun, 23 Feb 2020 16:31:31 +0000

Bench DMMs have an extra set of banana jacks called “sense.” Known as a Kelvin or 4-wire resistance measurements, these inputs accurately measure small resistors. Like, milliohms small. This video shows how to make a 4-wire measurement, prove when it is accurate, and alternatives to 4-wire. See below for an explanation of the alternative method shown.

Behind the scenes

Doing yet another DMM episode was a tough call for me. However, I am working on a project that requires me to characterize both a 1 ohm and a 100 milliohm resistor. The element14 community was kind enough to send me an MP720028 bench DMM. As shown in the picture, it has an extra set of banana jacks called “4-wire sense.” These connections make 4-wire resistance measurements. In this video, I show the same resistor measured with the traditional 2-wire and advanced 4-wire configuration. (Spoiler Alert! The 2-wire measurement was almost twice as big as the 4-wire!)

Digilent Analog Discovery 2 Review | Workbench Wednesdays

Sun, 29 Dec 2019 18:44:50 +0000

The Analog Discovery 2 combines all the equipment found on a typical electronics workbench into one small package. It packs an oscilloscope, logic analyzer, power supplies, spectrum analyzer, and so much more. As impressive as the hardware is, the Analog Discovery 2’s software, called Waveforms, is fantastic as well. You can configure it for any measurement situation, and it has extensive scripting capability. See if you should be considering adding the Analog Discovery 2 to your electronics workbench.

Function Generator Basics | Workbench Wednesdays

Sun, 29 Dec 2019 18:32:19 +0000

Generating signals with a waveform, function, or arbitrary generator lets you test all kinds of circuits. Learn how to get a function generator to output a signal, the 3 types of waveforms you can create, and which controls matter. James, the Bald Engineer, explains the difference between analog and digital generators.

The video introduction is my first attempt at doing an LGR style “Tech Tales” story. It is short with only a few images. However, it is something I would like to do more of in the future. My professional career started at Agilent right when they split off from Hewlett Packard. Most of my co-workers had been there while Bill and Dave still worked at the company. Even though the computer division took the name, Agilent was HP’s core: test and measurement.

Logic Analyzer Basics | Workbench Wednesdays

Sun, 29 Dec 2019 18:28:48 +0000

Logic analyzers capture digital signals and then display a waveform or list. Serial busses like I2C, SPI, or UART (Serial) can be decoded or triggered on when there are problems in your circuit. In this video, learn the basic controls you need to use (almost) any logic analyzer. You’ll learn how to set up a simple trigger, make measurements, and set things like sample rate or memory depth.

When I first graduated from college, I started as an Application Engineer for Agilent Technologies. Based in Austin, I supported computer companies like Dell, Compaq, HP, IBM, and Tandem. I helped their engineers set up million-dollar logic analyzer configurations to measure various PC busses.

Spectrum Analyzer Basics | Workbench Wednesdays

Thu, 17 Oct 2019 02:06:58 +0000

A spectrum analyzer displays signals in the frequency domain. To use one, you only need to know about four controls: reference level, center frequency, and resolution bandwidth. In this episode, see how to use a spectrum analyzer and determine the transmitting frequency of a device.

The example device is my microphone transmitter. It operates around 500 MHz with FM modulation. You’ll see how I step through the spectrum analyzer controls to find the exact frequency. At the end of the episode, I show some advanced measurements you can do with a modern spectrum analyzer. My favorite one is the demodulation.

Electronic Load Basics | Workbench Wednesdays

Wed, 18 Sep 2019 15:15:24 +0000

During the Bench Power Supply basics video, I made use of my electronic load. An electronic load can sink current from power sources such as power supplies or batteries. Loads are useful to test a power supply’s design margin or verify a battery’s capacity. See how three different instrument options from ultra low-end to midrange to high-end compare. After this element14 Presents Workbench Wednesday video, you will understand how to use modes on an electronic load like constant current and constant resistance to make different measurements.

Bench Power Supply Basics | Workbench Wednesdays

Wed, 28 Aug 2019 15:36:25 +0000

A bench power supply makes powering circuits easy and safe. Learn how to adjust basic controls like voltage. Finally, see how “current limiting” works (and why you should use it.) See how you can use built-in series or parallel tracking to increase a bench power supply’s voltage or current output. Last, if you are in the market for a power supply, do not forget to add some leads like mini-grabbers, alligator clips, and banana plugs.

DCA Pro Transistor Tester Review | Workbench Wednesdays

Wed, 07 Aug 2019 14:19:09 +0000

When it comes to transistors, there are only so many things a multimeter can measure. The DCA Pro from PEAK Electronics makes short work of testing parts like a transistor. This small device can determine pinout, component type, and essential parameters in a matter of seconds. Not only that but it can be connected to a (Windows) PC and draw parameter curves.

Check out the video review to see how the device and software work. Then head over to the element14 page where you can download a zip file full of example parts I measured for you. Use the free DCA Pro software to open them.

7+ Python Engineering Modules for Electronics Engineers

Thu, 11 Jul 2019 12:50:23 +0000

Python is everywhere. Its capabilities continue to grow. Not only can you create simple scripts, but you can create full-blown applications with it. The core has been scaled down to run on 32-bit microcontrollers like the ESP32 and Adafruit Feather M0. You can even use Python engineer modules to design stuff like circuits. There are electronics Python modules that create schematics, simulate circuits, and make solving math a cinch. Here are some of the modules I found that make Python usable for (electronics) engineering.

Hakko FX-888D Review

Wed, 03 Jul 2019 12:49:50 +0000

Just based on the color, the Hakko FX-888D seemed, at first, like it was a toy compared to other electronic tools and equipment. The color does make it easy to spot even if you are buried in a project. You can quickly find it because it stands out. The outside seems like plastic, but it is made from or encased in metal. Knowing that it was only a plastic enclosure made me feel like this will be with me for a long time.

Measuring ESR with the PEAK ESR70 | Workbench Wednesdays Review

Wed, 26 Jun 2019 14:50:45 +0000

There are three capacitor measurements you need to know how to make: capacitance, leakage current, and equivalent series resistance. Capacitance is easy to measure if you have a current limited supply or can use a resistor. Apply a voltage, then time how long it takes to charge up. You might need to use an oscilloscope or even an Arduino for the second part. Leakage current is the easiest of the three, apply a voltage (ideally through a resistor) for a few minutes, and then measure the current. ESR requires some special tricks. Since it is the resistance of the “wires” connecting to the capacitive element’s anode and code, you have to measure resistance without charging up the capacitor. (Otherwise, you get leakage.)

Raspberry Pi 4 Armchair Datasheet Evaluation

Mon, 24 Jun 2019 18:45:38 +0000

With the introduction of the Raspberry Pi 4, I dug into the announcement and datasheet while waiting for mine to arrive. Well, “datasheet” might be an exaggeration, but there is a list of the Raspberry Pi 4 tech specs available. That link gives a bullet item list of the main specs. In this post, I focus on these four:

Broadcom BCM2711, Quad core Cortex-A72 (ARM v8) 64-bit SoC @ 1.5GHz
Up to 4GB LPDDR4-2400 SDRAM (depending on model)
Gigabit Ethernet
2 USB 3.0 ports; 2 USB 2.0 ports.

There is a lot of very cool stuff on this $35 board. (Amazing they have kept that price point!) Or even the 4 GB $55 board. Adding Bluetooth 5, H.265 AND H.264 decoding, USB-C connector (Power), and changing the SoC to a 28 nm process are all significant improvements.

Introducing Bit Preserve

Wed, 12 Jun 2019 18:13:01 +0000

A project I work on in my spare time is creating a portable Apple II. Like many of my projects, one leads into another. I started out wanting to make a mobile Apple II, and now I’m working on a project called Bit Preserve. How did I get from one project to the next? Well, as I looked into how to make a portable Apple II, I realized a significant issue. The original Apple II logic board has almost 80 ICs. Being a design from 1975, they are all through-hole packages. The good news is that except for the ROM chips, they are all off-the-shelf components. But such a size means it might be impossible to turn it into something handheld. I almost abandoned the project. Then, I learned about a chip included in the Apple IIgs. The name of the ASIC is “MEGA II.” (Nothing to do with Arduino.) It is a chip that integrates all of those off-the-shelf chips into an 84 pin package.

Bald Engineer's ESD Must-Haves | Workbench Wednesdays

Wed, 05 Jun 2019 23:30:01 +0000

Electrostatic Discharge (ESD) damage can occur without you knowing it. That’s bad. However, the good news is that with little effort you can prevent it. Duratool has a kit of the most common tools for any electronics workbench. It includes a large mat, grounding cable, wrist strap, ESD-safe cleaner, and a simple electronic tester. Don’t get shocked by electrostatic discharge; add these simple tools to prevent it.

This review is on a kit that includes:

New Arduino Nano board from Maker Faire 2019

Wed, 22 May 2019 13:42:05 +0000

I had the chance to spend some time with the Arduino team before and during Maker Faire Bay Area 2019. I also attended Massimo’s “State of Arduino” talk. In short, there are new Arduino Nano boards coming, a certification available today, updates on the Vidor, interesting education kits, and one more special announcement.

It rained most of the weekend, which I am sure caused attendance to take a hit. Normally this would not be a big deal, but there was some talk it may be the last year for the Bay Area’s show. As usual, I walked the show on Friday and did take note there were several new exhibitors throughout. For that reason, I hope it is not the last one.

6 things I learned about KiCad at KiCon 2019

Fri, 17 May 2019 18:26:00 +0000

In April 2019, hardware hackers, hobbyist, and engineers joined together for the first KiCon. A couple of people asked me, “why is there a conference for KiCad?” Some questioned if KiCad was significant enough software to warrant a conference. That question is valid. But KiCon is larger than the KiCad software. Even in its first iteration, KiCon evolved more into a meeting for people building electronics hardware from small scale hobbyist to professionally designed systems, than just a conference on a single piece of software. Some might call it a maker conference. I call it a hardware developer conference. The key that tied everyone together is the open source software behind our printed circuit boards.

Tenma 72-2660 Portable Hand Held Supply | Workbench Wednesdays

Mon, 13 May 2019 13:25:12 +0000

The TENMA 72-2660 portable power supply offers bench supply capability in a backpack-friendly package. The single output is capable of 45 watts with up to 30 volts and 3.75 amps out. The built-in USB ports offer an easy way to power 5 Volts Arduino or Raspberry Pi projects while limiting their current. See how this portable supply performs, the things the Bald Engineer likes about it, and the points to consider before buying

Health and Solder Fumes | Workbench Wednesdays

Thu, 09 May 2019 13:18:20 +0000

An overlooked danger of electronics soldering is the fumes. While the smell and smoke may not be pleasant, the chemicals in the fumes can be harmful. Is solder made with lead(Pb) your only concern? Learn about where lead-free solder came from, what different flux types mean, and two ways to keep your air (and your lungs clean.)

In the video, I show a cheap “smoke eater” and a professional fume extractor. There is a cost difference of $50 and $700 between the two. However, either is better than having nothing.

7 MOSFET Myths and Misconceptions Addressed

Wed, 08 May 2019 13:03:24 +0000

The most popular AddOhms video is my short tutorial on MOSFET basics. In the years since I posted the video, people have sent me many questions. While answering those questions I’ve learned quite a bit as well. For example, in that video, I say that Vgs is the threshold to turn on the MOSFET. Well, it turns out, that is not entirely true. It is the threshold to turn it off! Oops. A minor point with a subtle difference, but a common MOSFET misconception.

Preserving history with KiCad - KiCon 2019

Sat, 27 Apr 2019 15:47:06 +0000

View the presentation on SlideShare

Classic, vintage, or retro computer systems are well documented on sites like Wikipedia. Their historic position is well known. Their schematics are even published from original documentation. But how useful are those schematics in their current form? (Spoiler, not much.) Presented at KiCon 2019.

Download Slides (8mb)

Low side vs. High side transistor switch

Wed, 10 Apr 2019 13:45:02 +0000

A common task for a transistor is switching a device on and off. There are two configurations for a transistor switch: low side and high side. The location of the transistor determines the type of circuit and its name. Either transistor configuration can use a BJT or MOSFET.

In this post, I draw the configuration for both transistor types, discuss which requires a driver, and explain why you would use either. If you are new to transistors, check out the resource links at the bottom. I have a few videos I made and some from element14’s The Learning Circuit, which do a great job introducing transistors.

KiCon 2019 - Preserving history with KiCad

Thu, 04 Apr 2019 01:35:42 +0000

On April 26th and 27th, the first year of KiCad KiCon kicks off in the Windy City. Join me and 26 others for talks about the open source electronics CAD tool. The list of speakers is impressive. There are many names which I follow on social media and some I recognize from the KiCad team. For example, Wayne Stambaugh is the KiCad project leader and has one of the keynote talks.

High-end Oscilloscope report on Evaluation Engineering

Thu, 28 Mar 2019 13:21:26 +0000

The concept of high end varies depending on what you are talking about and who you talk too. In this Evaluation Engineering Evaluation Engineering article the author discusses high-end oscilloscopes. I am mentioned several times in this article as part of my day job at Rhode and Schwarz. There I am a product manager for oscilloscopes in North America. We have scopes that range from 50 MHz to 8 GHz.

For a little bit of context let me explain how this type of article works. The author, or editor, reaches out to some field experts. Each person is asked to fill out a written interview form. From there the author compiles the responses into a story like this one. This process is always nerve racking to me. I always worry I’ll misquote a specification or make a major typo. I don’t get see the article until it is published.

Surface Mount Rework Tools | Workbench Wednesdays

Thu, 28 Mar 2019 03:21:42 +0000

In this element14 Workbench Wednesdays episode, I review tools provided by Weller which are suitable for surface mount soldering. Throughout the soldering series, I have been using mini-projects to see how the gear works. Making this particular video was special to me. The subject was a TI-85. Back when I was a kid, one of my first soldering projects was to replace a capacitor in the TI-85. At the time, all I knew is that the change would make it run faster. I didn’t know why I just knew it worked.

Polymer Capacitor Introduction on e14s The Learning Circuit

Tue, 26 Feb 2019 06:08:06 +0000

If I were a professional actor, I would feel typecast at this point in my career. Whenever someone wants to talk about Arduino, Oscilloscopes or Capacitors, they call me! In this case, element14 asked me to do two videos on how to replace multilayer ceramic capacitors (MLCCs) with Polymers.

Soldering Tool Upgrade Paths | Workbench Wednesdays

Sat, 09 Feb 2019 01:45:15 +0000

Right after the digital multimeter, or DMM, a soldering iron is a must-have tool for electronics work. Like most tools, there is a vast variety of options available. In this episode of element14’s Workbench Wednesdays, I look at a range of instruments from Weller. They offer everything from a cheap $10 “fire starter” (sorry, it is what we call them!) all the way up to a full-blown surface mount rework station.

Whether you don’t have a soldering iron or you have a $100 station, this video will show you options to consider when thinking about an upgrade.

Answering BJT questions with Karen on element14's The Learning Circuit

Wed, 02 Jan 2019 17:29:28 +0000

Over on element14, Karen hosts The Learning Circuit. It is a tutorial show geared towards learning STEM basics. So far she has covered subjects like soldering, diodes, and how to make a DIY electromagnet. She did a great job on introducing BJTs and how they work. While I thought she provided a clear explanation of the internal workings, some members of the element14 community still had questions.

She invited me on to revisit BJTs and transistors to (hopefully) clarify the connection between how transistors physically work and how to use them.

Connect pins with KiCad Bus, Labels, and Global Labels

Wed, 21 Nov 2018 14:18:20 +0000

When your schematic has a large number of related signals, it is helpful to group them. In its schematic editor, KiCad has a few tools to help. Your end-goal helps determine which tools to use. For example, do you need a KiCad bus or a label? In this post, I explore how you can define signals, group them, and reference them across schematic sheets.

What is the Apple IIgs? - AddOhms Live Clip

Mon, 19 Nov 2018 14:04:01 +0000

During a live stream, I was asked: “What is the Apple IIgs?” In this AddOhms Live Twitch Clip, I answer the question.

The Apple IIgs was the last of the highly successful Apple II line of computers. The “GS” stood for “graphics” and “sound.” Compared to previous Apple II computers, the IIgs was a fully 16-bit machine. When connected to its proprietary RGB monitor, it rendered a gorgeous display. Sadly, not much software took advantage of the improved graphics and sound capabilities. The IIgs was fully backward compatible with the older 8-bit line of Apple II computers. Its compatibility was so good that most IIgs users only used it in the compatibility mode.

Creating Custom KiCad Schematic Symbol in 5 Steps

Wed, 14 Nov 2018 14:21:23 +0000

A new project I have started working on involves the Apple IIgs. It was Apple’s last 16-bit (and 8-bit) computer. Inside are many application specific integrated circuits, or ASICs, that make the IIgs an extraordinary member of the Apple II family. One chip, in particular, is called the “MEGA-II.” This chip takes all of the individual logic chips from the original Apple II design and incorporates them into a single 84-pin PLCC.

Drawing Apple MEGA-II Breakout in KiCad

Thu, 01 Nov 2018 13:00:30 +0000

There is a project that has been sitting on my “to do” list for too long. My lab notebook has several dedicated pages for it. But I have not made progress. I decided to take some advice I have given to other people. When you’re stuck on starting a task, break down the project until you find a piece small enough you can get it done with no problem.

The project involves the Apple IIgs. It was Apple’s last 16-bit (and 8-bit) computer. Inside are some application specific integrated circuits or ASICs that make the IIgs. The name with my attention is named “MEGA-II.” It takes all of the individual logic chips from the original Apple II design and incorporates them into a single 84-pin PLCC.

How to pick from all the Arduino boards

Fri, 26 Oct 2018 04:47:43 +0000

Looking through my parts boxes, I have counted at least 15 distinct “Arduino boards” in my collection. Either they are variants of the Uno form factor or they have different processors from the 8-bit boards. That number easily goes to 30 if I include boards with just the “Arduino header” on them. This pile of microcontrollers got me thinking, how does anyone ever choose the right board?

Arduino millis() plus addition does not add up

Wed, 10 Oct 2018 13:00:23 +0000

In the past, I’ve covered how to reset Arduino millis() and have provided a growing list of examples using millis(). While reviewing the code for the elegoo Penguin Bot, I was reminded of a millis() mistake I see often: addition. The only way to properly handle millis() rollover is with subtraction. Let’s look at why (and how.)

What is Arduino millis()

The Arduino library has a function called millis() which returns the number of milliseconds the processor has been running. On other platforms, you might see references to a “tick counter.” It is the same idea. A hardware timer keeps incrementing a counter at a known rate. In this case, that rate is milliseconds.

Penguin Bot from elegoo hands-on review of the kit build

Wed, 19 Sep 2018 18:50:22 +0000

Recently I received three packages from Elegoo Industries. They are a company based in Shenzhen China. Before those packages, I noticed their name several times on various electronics kits on Amazon. They asked me if I’d help them with a video that shows how to assemble their latest creation: Penguin Bot.

There is not much point in sharing that video with you unless you’ve purchased one. So instead, here is my review, or hands-on, of the kit. I will, however, show you a short Instagram video I made to show off Penguin Bot’s cuteness.

Learn Oscilloscope Basics with an Arduino Uno

Mon, 03 Sep 2018 14:10:11 +0000

Learning to use a new oscilloscope can be daunting. In this video, I show 5 measurements you can make using just an Arduino as your DUT. Learn how to offset voltage, setup measurements, enable infinite persistence, save reference waveforms, AND trigger (and decode) serial signals. For this video, Rohde & Schwarz was kind enough to send me an RTM3004. This video is a follow-up from an ealier blog post which featured 6 scope measurements you can make with an Arduino.

Bank to the Future on element14 presents

Thu, 30 Aug 2018 01:37:07 +0000

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Making tutorial videos and project videos is a very different process. It is very easy to script a tutorial. In fact, I think it is a necessary step. Project videos, on the other hand, are more organic. In this project, I build a capacitive activated coin bank, based on this Coin Acceptor from Adafruit. It uses an MSP430 to do capacitive sensing and then a Pryamiduino to control the rest of the electronics. In the end, I do some classic AddOhms special effects to demonstrate how the project works. For detailed notes and design files, hit the button below for the element14 project page.

Arduino MKR Vidor 4000 Hands-On

Wed, 15 Aug 2018 13:27:52 +0000

Earlier this week, I looked at the Arduino MKR Vidor 4000 during an AddOhms live stream. My goal was to understand the Vidor better. It is the new FPGA-based Arduino which started shipping this month. It runs about $60. You can learn more at the Vidor Product Page on the Arduino website.

In this post, I briefly touch on the difference between an FPGA and a microcontroller. Then I walk you around the MKR Vidor 4000’s board. Using one of the examples, I talk a bit about how the various chips communicate with each other. This section also highlights what makes the Arduino FPGA board different from other development boards. Lastly, I answer “should you buy an Arduino MKR Vidor 4000?”

MKR 4000 VIDOR Hands-On Video | AddOhms Live

Tue, 14 Aug 2018 13:47:52 +0000

As promised, the Arduino team shipped the MKR 4000 VIDOR by the end of July. The graphical editor is still missing in action, but you can check out the board now. I received mine. In this AddOhms Live Stream, I turned it on and checked it out.

This video is a “working” live stream. Generally, I try to set up some demos and run through some canned actions. Not this time. I used the board once, on another computer. You get to watch how I attack a new board…live! Warts and all.

Standalone Arduino Turn-On and Debug

Mon, 09 Jul 2018 13:00:54 +0000

This AddOhms episode is part 3 of the “design your own Arduino” series. In this one I populate a bare PCB, reflow solder it, debug a few issues, and load the Uno bootloader. Originally, I designed 2 versions of the board. One version contained an error that I planned to fix in the episode. Well, turns out, the “correct” board had two issues which were more interesting.

Check out the #27 show notes for links to a bunch of stuff in the episode, including the design files.

Five Arduino math fixes for when it is wrong

Wed, 04 Jul 2018 13:16:52 +0000

While the Arduino library does an excellent job of hiding some of C/C++’s warts, at the end of the day, it is still just C/C++. This fact causes a few non-intuitive issues for inexperienced programmers. When it looks like Arduino math is wrong, it is probably one of these reasons.

When people ask me for help with their programming, I check each of these Arduino math mistakes. If your code seems to be hitting a bug, check to make sure it is not how the compiler handles math.

Arduino EEPROM stores any datatype

Wed, 20 Jun 2018 13:00:46 +0000

Funny how a simple idea can spider out into multiple paths. Arduino EEPROM seemed like a straightforward concept. A few a years ago it was as easy as having either 512 or 1024 bytes of flash memory. The Arduino IDE offered an EEPROM library which let you read and write a single byte. Today, however, with many different processor architectures saving data to EEPROM varies. It is now possible to save any datatype to EEPROM but not on all boards and not all using the same method.

Programming Adafruit Coin Acceptor on AddOhms Live

Mon, 18 Jun 2018 06:00:26 +0000

This week the bald engineer unboxes swag from electromaker.io, programs the Adafruit Coin Accepter, with a Pyramiduino, and answers questions along the way.

Interesting time code jump points:

7:59 - See Programming Bootloader Clip
12:11 - Coin Acceptor Programming
18:00 - Pulses on the R&S RTM3004 Oscilloscope
42:05 - Code working as intended!

Learn Six Oscilloscope Measurements with an Arduino DUT

Wed, 13 Jun 2018 18:44:22 +0000

One of the best ways to learn how to use a new piece of test equipment is to use it. Sounds easy, right? The problem is, sometimes when you are in the middle of troubleshooting your circuit, figuring out what the knobs on your scope do is an immense frustration. Use these 6 oscilloscope measurements, and just an Arduino Uno, to learn how to use a new or unfamiliar digital scope.

5 LDO Regulator Considerations other than voltage and current

Wed, 30 May 2018 13:03:28 +0000

For an AddOhms series, I created a DIY Arduino I am calling the “Pyramiduino.” It is an ATmega328p based board in the shape of a triangle. Other than being cute, the shape does not offer any other benefit. The design features a 3.3 volt LDO Regulator, which is also the subject of this post.

I forgot a fundamental aspect of design: read the freaking datasheet. The board’s LDO regulator was not turning on. Adding a passive scope probe to the circuit suddenly fixed the problem. The regulator turned on. When touching the enable pin, it measured about 1.25 volts. While I am sure Rohde & Schwarz would like me to ship scope probe with each board, that was not an option. With the impractical fix in place, I got to thinking about that voltage level. I remembered that the datasheet mentioned about 1.2 volts was needed for the “HIGH” threshold. Which meant, 1.25 volts applied to the pin enabled an active low input. Not only that, I remember the datasheet clearly said it had a pull-down resistor built-in. What was going on?

Creating an AddOhms Animations - Behind The Scenes

Mon, 28 May 2018 13:00:05 +0000

Pretty often I am asked about how I create the AddOhms animations. Currently, I’m working on the final part of the DIY Arduino Series. In the first part, I showed the elements of an Arduino schematic. The second part showed an overview of the PCB design. Finally, I will take the finished board and explain how to turn it on the for the first time. Lucky for me, there was a “mistake” on the board. This error gives some context for the episode.

Maker Faire 2018, Bald Engineer's Highlights

Wed, 23 May 2018 18:54:34 +0000

The Bay Area’s Maker Faire 2018 encompasses an impressive scope of activities. Pedal-powered live music, fire-breathing machines, kids building stuff, corn dogs, fresh honey, LEDs, soldering, roaming robots, and so much more. The last couple of days I made a few posts on the things I saw at Maker Faire. In this post, I’ll summarize many things that don’t fit together, but I wanted to mention that I enjoyed seeing.

Bay Area Maker Faire 2018 Photo Gallery

Wed, 23 May 2018 17:57:41 +0000

With the Bay Area Maker Faire over, I’m wrapping up my coverage with a photo gallery of my favorites. Some of these have been covered in my other Maker Faire 2018 posts. So check those out for details. FYI. Some of the products in this gallery will be covered in future posts.

Maker Faire 2018

5 Unexpected Brands at Maker Faire 2018

Tue, 22 May 2018 19:51:28 +0000

Maker Faire, like any festival, is a combination of passion products, startups, and larger companies generating awareness. As I walked around, I noticed many logos and brands. An obvious one to see is Make Magazine. Another I saw that made sense is Digi-Key’s maker.io. They had a strong showing, along with the Arduino booth. But that one is expected since so many projects, not just electronics, have an Arduino in them. That said, there were five brands that I did not expect to see at Maker Faire (and most had something interesting to show.)

Arduino Uno WiFi Rev 2 Features I noticed

Tue, 22 May 2018 02:10:34 +0000

Arduino announced several new products at the 2018 Bay Area Maker Faire. One of those products is the Uno WiFi Rev 2. (Check out this post for an introduction to the MKR Vidor 4000, an FPGA-based board. You can read their official announcement here. This new Uno board represents a significant upgrade for the 8-bit family of Arduino boards. However, I do have a few reservations.

Arduino Uno WiFi Rev 2

Starting off, I am not happy with the name. It is too long. For that reason, I am going to keep using the full name in this post to demonstrate why I don’t like it. Another reason I’m grumpy it that new microprocessor makes it incompatible with 328p code. That said,sketches (and libraries) using only the Arduino library will (likely) work fine. Anything that uses registers, like direct port manipulation, will have issues. Just like moving to any other architecture supported by the IDE. However, because it has the name “Uno,” many users will be tripped up by incompatibilities.

MKR Vidor 4000 brings FPGA to Makers

Mon, 21 May 2018 21:44:26 +0000

Arduino announced several new products at the 2018 Bay Area Maker Faire. One of those products is the MKR Vidor 4000, an FPGA-based board. You can read their official announcement here. (Over here is a write-up on the new Uno WiFi Rev 2.) The goal of the MKR Vidor is to make FPGA accessible to makers and innovators. It represents a new shift in hardware focus for the Arduino team.

An FPGA is a Field Programmable Gate Array. In other words, it is reconfigurable hardware. Unlike a microcontroller, an FPGA is not running software. Instead, its gate array changes configurations for a specific task.

Picking Pull-Up Resistor Value | AO #25

Fri, 04 May 2018 21:14:16 +0000

Common question that comes up about pull-up resistors: what value do you pick and why not just use a piece of wire? In this follow-up electronics tutorial, the bald engineer looks at how to pick a pull-up resistor value. Note that while focused on pull-up everything said in this video would apply to pull-down as well.

If you’re new to pull-up resistors, check out this longer Pull-Up Resistor Tutorial.

Watch the full video

Oscilloscope Probes Primer - Why so many types?

Wed, 02 May 2018 22:06:58 +0000

Unless you have a BNC or SMA connector your board, you will need a probe to get signals into an oscilloscope. Understanding what kind of oscilloscope probes are out there, which ones should you have for your scope and which ones to use for different measurements can be daunting. In this post, I look at some common scope probe types and offer some suggested measurements for each.

This post is not a comprehensive guide of oscilloscope probes. I am covering the types I have used. I do think this information should be enough to least form questions to ask your vendor before purchasing. Asking questions is important. If you have never bought specialized oscilloscope probes, you might not realize they can cost more than the scope itself. Maybe not an individual probe, but get one for each channel, and the cost rises. So picking the correct probe type is essential.

EAGLE 9 First Look - Couple of things I noticed

Wed, 25 Apr 2018 13:00:21 +0000

Autodesk released EAGLE 9. This new version continues the improvement that Autodesk has been providing since acquiring the infamous ECAD tool. There are three areas I look at in this AddOhms Livestream.

How I looked at EAGLE 9

In the beginning, I use an old training class I wrote about five years ago when I was using EAGLE daily. It shows how to design a 555 flashing circuit from schematic to PCB. A follow-on class taught how to mill the PCB on a Shopbot. I might update the course and release it if I have time. The exercise class helps me find some surprises with EAGLE’s incremental improvements.

FPC1500 Review, a Rohde & Schwarz Spectrum Analyzer

Wed, 04 Apr 2018 13:00:15 +0000

Everyone’s first piece of test equipment should be a multimeter. Next is probably a power supply with current limiting. For many engineers, the next step is an oscilloscope. At least those working on digital electronics. Even if you are not working with RF, do not overlook a spectrum analyzer. The Rohde & Schwarz FPC1500 is three instruments in one: a Spectrum Analyzer, RF Signal Source, and a Vector Network Analyzer. In this post, I combine an FPC1500 review with an introduction to these frequency domain tools.

IoT: Intelligent Outsourcing

Wed, 28 Mar 2018 20:37:14 +0000

Whether you are developing a WiFi-enabled coffee maker, a sensor to detect rainfall, or a livestock tracking drone, an IoT device will follow the same product development cycle.

A common mistake that engineers will make is trying to own the development at each stage, at least up until “deliver.” Who can blame us? The idea of delegating any part of our new product introduction can be daunting. Delegating, or outsourcing can be a powerful tool. It allows you to focus on the elements of your process that only you can do. Let others handle the rest. If your core contribution is the machine learning algorithm, then focus your effort there. Spending time designing the enclosure, or negotiating with suppliers, or even laying out the printed circuit board is a waste. Let the people who excel in each of those areas apply their expertise to your product.

Weller Zero Smog EL Review on element14

Wed, 14 Mar 2018 13:00:18 +0000

I have been soldering circuits for twenty-six years. Well, except for the last 6 weeks. I have had a Weller Zero Smog EL fume extraction unit in my lab. It has changed the way I solder. When I first used it, I thought “yes, this is nice. But not a necessity.” Then the other day I didn’t feel like moving the extractor to my secondary workbench. I was immediately irritated with myself for being lazy. The smoke was so annoying. I don’t know what else changed me so quickly.

DIY Arduino PCB Pryamiduino (Video)

Wed, 28 Feb 2018 14:00:03 +0000

Continuing the DIY Arduino tutorial series, this AddOhms episode shows how to create a PCB in KiCad. I make a joke that the original design was a rectangle, which I found boring and pointless. So instead, I designed a triangle to give the board 3 points. Get it? Puns! I am calling it the Pryamiduino. To be honest, I found not having a constraint to be a problem. By forcing a specific board size and shape, many decisions were more manageable.

Debug SONOFF AC Relay with a Thermal Camera

Thu, 22 Feb 2018 03:43:36 +0000

My recent SONOFF WiFi Switch experience reminded me of something from high school. I attended an off-site electronics class with my best friend. As teenage boys, we were prone to doing stupid things. One of our favorite games was to see who could handle the highest voltage. Our bench had a variable AC supply that went from 0 to 120 volts. So we would grab the alligator clips while the other person slowly turned the knob up. John once made it to 50 volts. I seem to recall my tolerance around 30 volts. First, DO NOT do this. It was stupid. Second, I think this game is why handling AC makes me so uncomfortable.

Circuit Python adds Python to Microcontrollers

Wed, 14 Feb 2018 14:57:09 +0000

Back in 2013, a Kickstarter ran for a project to put a python interpreter on a microcontroller. At the time I could not see the benefit. Cool project, but I asked myself: “why?” On my last Adafruit order, I received a free Circuit Playground Express. The board comes with CircuitPython pre-installed. After playing with Circuit Python, or CP, I finally “get it.”

For Valentine’s Day, I made an animated LED heart for a new love in my life, Circuit Python. Well, love is a bit of a strong word. The past couple of weeks I have been l earning Circuit Python, and I am excited by what it offers.

Hologram.io connects Adafruit FONA

Thu, 08 Feb 2018 03:00:18 +0000

While the buzzword “IoT “is relatively new, there has been a long time “internet of things” in operation. Those devices are called the far less sexy term “M2M” or machine-to-machine. These devices, around since the 90s, contain a microprocessor, some sensors, sometimes electromechanical hardware, and a cellular radio. These M2M devices were (and still are!) the early “Internet of Things.” Thanks to Hologram.io, you can join this new/old trend for free.

Signetics Write Only Memory 25120 Datasheet

Tue, 06 Feb 2018 20:18:37 +0000

Signetics started as an IC manufacturer. In 1975 they were bought by Philips Semiconductors, which is now NXP. Interestingly the address in the datasheet, I think, was the original site. Today, it’s home to a Lowe’s Home Improvement Store. According to this Wikipedia article, it was created by John “Jack” Curtis. Apparently, it was included in a real Signetics catalog as a joke! Imagine that happening today. Additional information about the joke is available on sigwom.com. (Which may be written by Jack himself, not entirely sure.)

Live millis() tutorial: AddOhms Live #5

Sun, 28 Jan 2018 19:47:46 +0000

&t=158s

When it is time to move away from delay(), it’s time to learn how to properly use millis(). If you’ve had trouble following my millis() examples, maybe a live tutorial will help.

In this AddOhms Livestream, I go through 4 code examples:

1. Blink, the one with delay(), as a starting point.

Adafruit Feather Review and Selection Guide

Wed, 24 Jan 2018 14:04:17 +0000

Four days ago, I found out I needed to make a piece of a costume. The idea was to combine a TFT LCD with a microcontroller and Bluetooth Low Energy. I checked my microcontroller bin and found some Adafruit Feather Boards. In this post, I will introduce the feather family and provide a decision chart for choosing the right one for your project.

adafruit-feather-layout

The Feather board have a standard footprint and pinout. Most(All?) have a USB connector, a microcontroller, two rows of pins, and a battery charger. They measure 50.80 by 22.86 mm, which is 2.0 by 0.9 inches.

DIY Arduino Schematic board and Checklist

Wed, 17 Jan 2018 14:00:18 +0000

One of the last significant steps in a project is designing the custom PCB. This stage means creating a DIY Arduino board that is custom to the application. Two examples of my past projects are BinBoo, a Binary Clock, and Open Vapors, my reflow oven controller.

While working on a project for a friend, I got to thinking; it would be nice to have a checklist for circuit elements to include on a DIY Arduino board. In the early days, I forgot to add a filter cap to AREF, for example.

What is the Bald Engineer doing?

Wed, 10 Jan 2018 19:37:46 +0000

The next AddOhms Tutorial is how to design a DIY Arduino board. What are the elements you need to include in your own circuit design? While editing the video, I ended up on this frame. It looked to me like I was praying. (At one point I was having serious technical issues with my equipment. But it is unrelated to that frame!) On Twitter, my friend Philip had a different take.

Unboxing Hackerboxes and more Q&A on AddOhms Live

Fri, 29 Dec 2017 18:51:01 +0000

Watch Archived Video: Unboxing Hackerboxes

Over the past year, I have been a Hackerboxes subscriber. When the first couple arrived, I opened them up immediately. In fact, I got my first ESP32 through Hackerboxes.

Sadly, I got caught up in so many things I stopped opening them causing them pile up. So to close out 2017, I’m Unboxing Hackerboxes live while answering your electronics questions.

2017's Best Bald Engineer Tutorials, Articles, and Reviews

Wed, 27 Dec 2017 17:45:25 +0000

As 2017 comes to a close, I looked back to see what readers made the most popular. It was an exciting year. The Arduino family came back together, Adafruit trolled the internet with rumors of a RadioShack buy out, and for me, I changed jobs.

Project wise I got my RetroPie SNES build completed, using an old Super Famicom case. This case is one I bought in Japan for 500 yen (about $5.) This work also led me to discuss voltage divider circuits. And I looked at a couple of scopes.

7 Arduino LCD display tips and tricks

Thu, 21 Dec 2017 17:30:03 +0000

When I started working on Open Vapors, I thought the stumbling point would be the PID algorithm or safe AC line control. However, it turned out; I spent a significant amount of time understanding how to print to the Arduino LCD display correctly.

Crazy Circuits Hands-On and Q&A (AddOhms Live!)

Mon, 18 Dec 2017 14:43:39 +0000

In April 2017 I backed a project on Kickstarter called “Crazy Circuits.” It looked like a cool concept that was well developed, so I even included it in the Baldengineer Newsletter. I do not typically promote Kickstarter projects–unless they are exceptional in some way. I liked the concept of circuits that worked with existing LEGO-sized boards and pieces. Their shipping was a couple of months off, but nothing compared to some Kickstarter disasters. I received my Crazy Circuits kit in November, compared to the promised September.

Arduino Keyboard Matrix Code and Hardware Tutorial

Fri, 15 Dec 2017 14:00:26 +0000

As a kid, I got the book " Upgrading and Repairing PCs." (Now in its 22nd edition.) It was the first book to explain to me the PC architecture. I considered, how were there so few pins on an AT-style keyboard connector when there were 101 keys on the keyboard? That is when I first learned about the keyboard matrix.

Intel_P8049_AH_controller

The keyboard matrix itself did not amaze me, but instead the idea there was an entirely separate 8-bit microcontroller inside of the keyboard. Early keyboards may have used the P8049AH, which, there is still some stock available to purchase. I was fascinated with the idea an entire computer was necessary to run the keyboard, to use my “real” computer. Why did it take something as complicated as a microcontroller?

Open Source Hardware Summit 2017 Recap

Wed, 01 Nov 2017 13:41:04 +0000

This year Denver hosted the 2017 Open Source Hardware Summit. It’s a one-day seminar with talks, demos, and a couple of drinks. The day after the official show Sparkfun and Aleph Objects hosted tours of their facilities. The combination of events made for a fantastic immersion into open source hardware.

There were many talks and demos setup during the summit. Here are three that caught my attention. Please note, this is not to rate or judge the quality of anyone’s work. Simply, a couple of weeks later these are the three talks that stuck with me.

PicoScope 2204A Review on element14

Tue, 31 Oct 2017 13:19:21 +0000

Previously, I wrote up a hands-on with the PicoScope 2204A. At the time I only spent a few minutes with the device. I used it to “debug” an I2C bus between an Arduino and OLED screen. Since that initial hands-on, I’ve used the PicoScope in my lab. Most notably, I hosted another “hands-on” via an AddOhms Live Stream. I used it for another live stream where I talked about op-amps. Unfortunately, the video isn’t watchable due to some technical difficulties.

Aluminum Polymer Capacitors on EE Journal's Chalk Talk

Mon, 30 Oct 2017 22:38:05 +0000

What are aluminum polymer capacitors? These are a solid type of capacitor that replaces the liquid electrolyte with a solid polymer material. Sometimes you might hear these capacitors called “organic aluminum.” Technically, they are still “electrolytic” capacitors. However, the colloquial term of “aluminum electrolytic” refers to the traditional wet electrolyte-based capacitors.

In this video, I meet with Amelia Dalton of EE Journal, and we discuss these capacitor types. Mouser and EE Journal developed the video in joint with KEMET. (Previously I talked on Amelia’s Chalk Talk about SSD Capacitors.)

Voltage Dividers as Regulators?! | AddOhms #22

Mon, 16 Oct 2017 13:00:15 +0000

Can you use voltage dividers as regulators? What if you add a Zener Diode? In this AddOhms episode, I show what happens when you try to power a complex circuit like an ESP8266 with a voltage divider instead of a regulator. (Spoiler: Get a voltage regulator.) This video tutorial is related to a write up I did recently on Zener Diodes. For questions or comments visit the AddOhms Discussion Forum.

Behind the scenes

A significant change for this AddOhms Episode is that I moved from Final Cut Pro X to Premiere Pro. I also shot the entire video in 4K, even though the output is 1080p. Animations were still done as 1080p compositions. One snag I ran into, the color corrections I applied in PPro, didn’t seem to get exported. You might notice when the breadboard is on screen, it has a very slight yellow tint to it.

FleaFPGA Ohm is a crowdsource project worth considering

Wed, 04 Oct 2017 13:31:38 +0000

Previously, I wrote a FleaFPGA Introduction. This board was about the size of an Arduino Uno with some GPIO pins, a VGA, USB, SD Card, PS2 Style Port, and a USB Host connector. At the time, the Lattice Mach XO2 provided the base logic. It found some success in the emulation community (*cough* x86 *cough*.) Unlike software emulators, the FPGA emulates the actual digital logic of classic computer ICs. Also known as ASICs.

Op Amp Circuits by Bob Pease

Wed, 27 Sep 2017 17:45:07 +0000

Op amps are one of the most versatile ICs in electronics. A purely analog device, they can be used for amplification, summing, integration, and a whole host of other circuits. AN-31 from Texas Instruments is 32 pages of op amp circuits. (Note: this document was created before TI acquired National Semiconductor.)

Even more amazing is that the author is Bob Pease. If you never heard of Mr. Pease, please spend a few minutes right now reading this TI page dedicated to him. His contributions to electronics are nearly immeasurable. (Sadly, he was involved in a car accident after attending the funeral of his equally famous engineering friend, Jim Williams.)

Zener diode makes for a lousy regulator

Wed, 20 Sep 2017 12:57:08 +0000

The Zener diode is often used to create a reference voltage. In tutorials and even college texts, there are mentions of creating a Zener diode based regulator. The idea is that the Zener maintains a known voltage drop. The problem is that current matters. This post looks a quick Zener diode overview and shows what happened when I tried to power a microcontroller using a “Zener diode regulator.”

Zener diodes overview

Just a brief overview if you are not familiar with Zener diodes. Like typical diodes, Zeners have low forward voltages. Typically you voltages are around 0.7. However, different material sets can offer different forward voltages.

Op Amps featuring the XL741 (and Q&A) on AddOhms Live!

Wed, 20 Sep 2017 03:40:45 +0000

Download AddOhms Live iCal Reminder

Sunday September 24, 2017, I will host the 2nd live stream of AddOhms. My first live stream was a test for the technology pieces. I’ve made some refinements and am giving it a second try. For that reason, I’m keeping the topic really simple.

The Agenda for the Live Stream is:

Introduction
News (3 stories or projects that I found interesting)
Op Amps with the XL741
Q&A
Whatever surprises pop-up.

In the livestream, I’ll be talking about inverting and non-inverting circuits using an op-amp. But I am not going to use just ANY op-amp. I’ll be using the MASSIVE XL741! (I did a review of Evil Mad Scientist Lab’s XL741 in the past.)

PicoScope 2204 Review and Hands-On

Wed, 13 Sep 2017 12:21:32 +0000

If you need a reason to be an Element 14 member, let me suggest their Road Test program. Companies partner with Element14 to get people to try out their gear. A couple of years ago I got a new microcontroller board. This week I received a new test instrument. Here’s my hands-on Picoscope 2204 review.

The scope is bus powered. With the BNCs and type-B USB connector, it is slightly larger than an external USB hard drive. There is not much weight to the device. It does not feel cheap, just lighter than I expected.

Enterprise SSD Capacitor Chalk Talk

Mon, 04 Sep 2017 17:01:20 +0000

&t=69s

In this video, I discuss considerations for SSD Capacitors, with a focus on enterprise applications. (No, not the ship kind, the business kind.) As more consumer devices use solid state technology, it gets easier for us to forget the importance of keeping data safe during storage. While solid state drives are more robust than their spinning counterpart, they are not perfect. Just like with spinning drives, there is a small delay from when a write occurs until the data is stored permanently. The highest performance solid state drives parallelize data in a way to minimize this propagation time. However, these drives also keep an active copy of the allocation table in RAM.

5 Voltage divider circuits that go beyond dividing

Wed, 23 Aug 2017 13:19:15 +0000

Here are some ideas of what you can do with the humble voltage divider. This elementary circuit has a few inventive uses. To be upfront, one of these uses is NOT as a voltage regulator. If you need a voltage regulated, get a voltage regulator! At some point or another, I’ve built all five of these voltage divider circuits. For me, the voltage level shifter is the most common.

Pi Cap Hands On Review

Wed, 16 Aug 2017 13:05:52 +0000

The Pi Cap adds capacitive touch buttons to your Raspberry Pi. Bare Conductive was kind enough to send me one. I do not have a project in mind right now, so here are my first impressions.

What is the Pi Cap?

Arduino tends to call daughter cards shields, while the Raspberry Pi community calls them hats. The Pi Cap is a hat. It plugs into the GPIO header of a Raspberry Pi and provides 13 capacitive touch pads. There is a traditional push button, an LED, and a prototyping area. While the Pi Cap does consume all of the GPIO pins, several are broken out near the GPIO header.

Brushless DC Motor Introduction | AddOhms #21

Wed, 26 Jul 2017 13:20:18 +0000

The first part of the tutorial looks inside of a Brushless DC Motor, or, BLDC. Then I show a discrete transistor circuit that can drive one. Of course, you’ll need a Microcontroller like an Arduino to drive it! Lastly, I briefly talk about an ESC.

Overall, a BLDC is better than a Brushed DC Motor (talked about those on #20) because:

There are no brushes to wear out
No sparks when the motor spins
You can get way faster RPMs out of a BLDC.

Check out the AddOhms #21: Brushless DC (BLDC) Motors. Show notes are available here.

Top of the P(acq) - Oscilloscope Talk

Mon, 24 Jul 2017 13:58:10 +0000

Supplyframe Hardware has published a video of a talk I gave in July 2017. This talk was at HDDG 22. The focus of my discussion was how an oscilloscope’s trigger circuit works. I built on that and talked about some of the behind-the-scenes stuff of what is going on with a digital oscilloscope. (You can download my HDDG 22 slides here.)

Aeroscope Review

Wed, 19 Jul 2017 13:11:36 +0000

Previously, I reviewed the smartphone DMM, Mooshimeter. It is a great meter. One feature I didn’t spend much time on in my review was the ability to graph. Some see it as an “oscilloscope alternative.” The past couple of weeks, I’ve been using Aeroscope. It is a Bluetooth-based oscilloscope about the size of an older active probe. The Aeroscope runs $199 direct from Aeroscope Labs. The question I address in this Aeroscope review: is it better to buy this, a USB-based, or standalone scope for about the same money. How does it measure up?

PWM a 3-pin PC fan with an Arduino

Wed, 05 Jul 2017 13:13:53 +0000

A question came up on IRC regarding how to PWM a 3-pin PC fan with an Arduino using analogWrite(). Controlling the fan was seemingly straightforward. The problem was that the hall effect sensor, or TACH signal, was incredibly noisy. The noise made it impossible to measure the fan’s rotation. Working through the question, I found three issues to tackle:

You need to use a PNP transistor
Filter capacitors help
Create a non-blocking RPM measurement (with millis())

This post addresses all three issues regarding how to PWM a 3-pin PC fan with an Arduino.

Oscilloscope Triggering: HDDG #22 Presentation

Thu, 29 Jun 2017 23:25:28 +0000

During #22 of the Hardware Developers Didactic Galactic meetup, I discussed Oscilloscopes. (Previously James talked about capacitors.) In the presentation, I broke down the internals of an oscilloscope. The presentation started off with a block diagram. Then I discussed the main components: vertical amplifier, A/D, memory controller, some of the computer side stuff, and the keynote was on triggering.

The trigger circuit of an oscilloscope fascinated me since very early in my HP/Agilent career. When I saw trigger modes like Pulse, Violation, Rise Time, and “Runt,” I thought: Wow, this must be the most complicated circuit in the scope! While it isn’t trivial, it very clever how just a few pieces of (relatively) simple hardware drive one of the most important aspects of a digital scope.

Raspberry Pi Startup Script Tutorial

Wed, 28 Jun 2017 13:03:46 +0000

The last couple of weeks I have been making progress and posts on my RetroPie build. I’m putting a Raspberry Pi inside of an actual SNES (well Super Famicom). Part 1 covered the schematic for a Soft Power Controller. In Part 2 I broke down the RPSPC state machine. This 3rd and final post of the series is a Raspberry Pi startup script tutorial. It covers how to make scripts run at startup and shutdown.

Signals Abound - #22 Hardware Developers Didactic Galactic

Tue, 27 Jun 2017 14:00:08 +0000

Oscilloscopes belong on the desk of every electrical engineer or hobbyist. They are invaluable in both debugging and characterizing a circuit. While most users can twist the knobs to make things show up on screen, most never fully understand what is happening behind the scenes. Having spent over a decade working at a couple of scope companies, I have unique insight into how these incredible machines actually work.

I’m super excited to be invited back to the Hardware Developers Didactic Galactic held at the SupplyFrame office (usually) in San Francisco. This time I’ll be talking about oscilloscopes (last time I spoke about Capacitors). The focus of my story is the mysterious “trigger” circuit found in all digital scopes. Which, ironically, is the last part of my presentation. ;)

Soft Power Controller State Machine

Wed, 21 Jun 2017 13:00:43 +0000

Previously I looked at the hardware needed to build a Raspberry Pi soft power supply. This week I’m looking the state machine for the microcontroller. Why is such a complicated circuit necessary? I am replacing a Super Famicom (SNES) motherboard with the Pi. The trick is, I want to use the original power switch to turn the Pi on and off.

This requirement presents a problem. When the switch goes into the “OFF” position, power needs to stay on long enough for the Pi to properly shutdown. So the switch itself can’t provide power to the Pi directly. With minor changes, the code in this state machine could be made to work with push buttons as well. If I add that feature in the future, I’ll update the code on the RPSPC GitHub project.

Raspberry Pi Soft Power Controller - The Circuit

Wed, 03 May 2017 23:18:56 +0000

The RetroPie project enables retro-gaming with a Raspberry Pi. All of the Pi models have enough computing power to emulate the major 8-bit and 16-bit computers of the 80s and 90s. With the Pi 3 I have even been able to play PS1 games with no problem. My current project is to put my Raspberry Pi running RetroPie into an old Super Famicom (SFC), or SNES, case. The catch? I want the original SPST power switch to work. And by work, I mean allow the Raspberry Pi to shutdown properly when the switch goes into the off position. To accomplish this task, I am building a Raspberry Pi soft power controller.

Share projects on one of these 4 platforms

Wed, 26 Apr 2017 13:00:54 +0000

Sharing is the maker community’s foundation. When you share projects with others, you contribute to the community. In the past, you might just post your project on a personal website. Today there are many options to share projects.

This weekend I “finished” my reflow oven controller, Open Vapors. Believe it or not, five years ago there were not a bajillion similar projects. In fact, I based my design on the only completely open source project I found. It is a reflow oven controller Arduino shield from Rocket Scream.

Detect short and long button press using millis

Wed, 19 Apr 2017 12:00:48 +0000

To detect a short and long button press using millis can give your project more functionality without adding more buttons. In this line-by-line example, I show how to react to a user pressing a button for a short period (100ms) or a long period (over 500ms). My example changes the blink rate of an LED on short presses. A long button press turns off the LED.

In the code, I make use of a struct so that a single variable can be used to track multiple parameters. The benefit of this method is that adding multiple buttons is easy. You could create an array of these tyepdef’d variables.

7805 is at the heart of a Super Famicom / Super NES

Sun, 16 Apr 2017 00:37:01 +0000

When I made the AddOhms Tutorial on Linear Regulators, I made a comment about the 7805. I said it may be one of the most important Integrated Circuits (ICs) ever made. That’s a bold statement. The 555, 805, or 7400 might all qualify for such a distinction. My feeling about the 7805’s importance is because it is a chip that is still popular today. It is used, or at least was used, in so many applications. And it is the heart of many 5V digital systems.

Best Sorting Resistors Method

Wed, 12 Apr 2017 13:00:51 +0000

When you buy a grab bag of components, you might need to tackle sorting resistors. Here’s how I sorted some bags of random resistor assortments last week.

Objectives

Then method I use for sorting resistors achieves these objectives:

Fewer Bins. It doesn’t take long to create a large matrix of resistor values. My resistor sorting method is relatively compact.
Quick to find. When I’m building up a circuit, I don’t want to spend time sorting through a pile. Once I know the value I need, I find a single package and then look for a single color band.
Works with 4-band and 5-band resistors. Let me be upfront: I *hate* 5-band resistor color codes. While the 5th ring is supposed to be slightly offset, or wider, or a different type of color; it doesn’t matter. It’s nearly impossible to tell read a 5-band resistor color code when they are in a pile. However, using my method for sorting resistors, it doesn’t matter if I’m looking at a 4-band or 5-band resistor. I can immediately identify the resistor value.

Based on #3 alone, you might be wondering what is the fantastic method (and how much will it cost to get it!) Here’s the basics of my method for sorting resistors. (For FREE!)

Arduino Data Logger: Serial Monitor Alternatives

Wed, 05 Apr 2017 13:00:56 +0000

The Arduino serial monitor is usable when you want to watch data from an Arduino. However, it does not have a built-in method for saving the data. Here are some ideas if you want to build an Arduino data logger with or without a PC.

Important note on Arduino Data Logger examples

With all of these examples, please remember that whenever you open the Arduino’s serial port, the board will reset. So if your log file shows “Initializing SD card…” with a few data lines in between, it is because there is a reset happening.

Sending simple serial commands to an Arduino

Wed, 01 Mar 2017 15:00:16 +0000

Sending simple serial commands to an Arduino is the easiest way to communicate between an Arduino and a computer. The computer could be a PC, a Raspberry Pi, or any device that communicates with serial.

By sending and “decoding” a single character it is easy to add a simple debug menu or even serial menu. Plus, it is easy to extend.

Single Character vs. Full Words

The mistake I see many people make is that they try to send full-text strings as serial commands. For example, to turn on a LED, I have seen (silly) commands like “RED LED ON” or “RED LED OFF.” While you could use something like strcmp(), as I showed on the Multiple MQTT Topics example, that tends to be overkill for most serial commands.

Multiple MQTT Topics with Arduino PubSubClient

Wed, 01 Feb 2017 13:00:22 +0000

In my Arduino MQTT Examples, I kept things simple by only subscribing to a single topic. One of the strengths of MQTT is that a device can subscribe (or publish) to multiple topics. The broker will sort things out. Even though my first example only showed one, it is straight forward to get the Arduino PubSubClient library to subscribe to Multiple MQTT topics.

The quick answer is that you need to look at the MQTT response to find out which topic sent the payload.

Why ceramic capacitors change capacitance

Fri, 06 Jan 2017 23:18:03 +0000

It is commonly known that ceramic capacitors change capacitance with applied voltage. What isn’t always as well known is how strong this effect can be and why it occurs. At KEMET we’ve put together a technical video that answers that question.

What is Ask An FAE?

Ask An FAE is a new video series we launched at my day job, KEMET. An FAE is a field application engineer. These engineers are very common in the electronics industry. Companies like KEMET, where I work, have FAEs who meet with customers to answer technical (and very detailed) questions about how to use their products. In UBM’s Mind of an Engineer survey, FAEs were ranked as one of the top information sources for design engineers.

2016 Great Year for Enginerds

Wed, 04 Jan 2017 14:01:49 +0000

While many want to call 2016 the worst year ever, I feel that is an entirely undeserved title. It certainly could have been a better year, but it wasn’t the worst that I can remember. For the engineering community, both professional and hobbyist, it seems to have been a fantastic year. My gauge for this feeling is the activity on baldengineer.com. In 2016, I saw almost half a million sessions contributing over 1.2 million page views. (That’s 98% more people looking at 313% more tutorials compared to 2015.)

Ripping apart soda cans with an Electromagnet

Fri, 23 Dec 2016 15:31:09 +0000

ArcAttack is a band that performs at the Bay Area Maker Fare, among other places. They feature massive signing Telsa coils. (Here’s a video I show when I saw ArcAttack in 2013.) Singing Telsa coils are awesome. Everyone knows that. Which is why I found when Dianna Cowern, the Physics Girl, visited the band ArcAttack, electromagnets are just as cool. In addition to talking about their music, ArcAttack’s Joe does something amazing. He splits an aluminum soda can with just an electromagnet.

Wolfenstein 3D on Gameboy Color

Tue, 20 Dec 2016 15:00:41 +0000

Wolfenstein 3D defined the FPS genre in a way no one could have predicted. Just like the Gameboy defined portable gaming in a way no one could have predicted. Cartridge based computing and gaming offered something that disk (or disc?) based media never could: additional hardware.

If the Moon Were Only 1 Pixel

Mon, 19 Dec 2016 17:41:43 +0000

A tediously accurate scale model of the solar system

When I was growing up, I watched a lot of Star Trek. Over time I’ve looked into other Sci-Fi series. The occasional hit, like the reimaged Battlestar Galactica, caught my attention. But, for me, the voyages of the Enterprise defined “space” to me. Or the stories on Deep Space Nine. (There are no other Star Treks.)

Mooshimeter Review - Smartphone Multimeter

Wed, 07 Dec 2016 17:23:41 +0000

For fifteen years I used my Radio Shack 22-168A digital multimeter as my go-to meter. A couple of years ago I bought a Fluke 115. Not because the RS meter lacked a measurement, but because I wanted a backlit screen. Here’s the crazy thing though in 20 years of multimeter development, there hasn’t been much innovation. Well outside of maybe auto-ranging.

All three meters I have, plus the Virtual Bench I reviewed about a year ago all continue to have the same limitation: they can only perform one measurement at a time. That’s one feature that makes my latest meter, the Mooshimeter, unique. It can measure both voltage and current at the same time. Oh, and it doesn’t have a screen.

Fading LED: analogWrite millis() Example

Wed, 23 Nov 2016 14:34:21 +0000

It’s a well-known fact of engineering: LEDs make everything look better. And that means a Fading LED is even better. Using Arduino’s analogWrite(), fading a LED is just a matter of a loop. If you use delay(), you can’t easily add other actions. What can you do? Well, Fading a LED with millis() is pretty simple. Here’s the code to do it and a quick explanation.

//pwm-fade-with-millis.ino
// Example Fading LED with analogWrite and millis()
// See baldengineer.com/fading-led-analogwrite-millis-example.html for more information
// Created by James Lewis

const byte pwmLED = 5;

// define directions for LED fade
#define UP 0
#define DOWN 1

// constants for min and max PWM
const int minPWM = 0;
const int maxPWM = 255;

// State Variable for Fade Direction
byte fadeDirection = UP;

// Global Fade Value
// but be bigger than byte and signed, for rollover
int fadeValue = 0;

// How smooth to fade?
byte fadeIncrement = 5;

// millis() timing Variable, just for fading
unsigned long previousFadeMillis;

// How fast to increment?
int fadeInterval = 50;

void setup() {
 // put pwmLED into known state (off)
 analogWrite(pwmLED, fadeValue);
}

void doTheFade(unsigned long thisMillis) {
 // is it time to update yet?
 // if not, nothing happens
 if (thisMillis - previousFadeMillis >= fadeInterval) {
 // yup, it's time!
 if (fadeDirection == UP) {
 fadeValue = fadeValue + fadeIncrement;
 if (fadeValue >= maxPWM) {
 // At max, limit and change direction
 fadeValue = maxPWM;
 fadeDirection = DOWN;
 }
 } else {
 //if we aren't going up, we're going down
 fadeValue = fadeValue - fadeIncrement;
 if (fadeValue <= minPWM) {
 // At min, limit and change direction
 fadeValue = minPWM;
 fadeDirection = UP;
 }
 }
 // Only need to update when it changes
 analogWrite(pwmLED, fadeValue);

 // reset millis for the next iteration (fade timer only)
 previousFadeMillis = thisMillis;
 }
}

void loop() {
 // get the current time, for this time around loop
 // all millis() timer checks will use this time stamp
 unsigned long currentMillis = millis();

 doTheFade(currentMillis);
}

Global Variables for Fading LED

Constants

The constant “pwmLED” is the pin that gets faded. (Make that pin supports analogWrite().) The two #define statements, UP and DOWN, are simple states for the LED. They make the code easier to read. The “maxPWM” value is set to 255 for 8-bit AVR boards like the Uno. If you’re using the ESP8266, set this value to 1023. (You can also use the constant “PWMRANGE.”)

Insert Caption Here

Tue, 22 Nov 2016 17:38:12 +0000

Took this screenshot while I waited for the AddOhms Q&A #02 Video to finish rendering. What could I be pondering?

(If this site still had comments, I would say leave it here…)

Electron Microscope Analyzing Vinyl Records (and other Spinning Media)

Mon, 17 Oct 2016 13:57:56 +0000

Ben Krasnow from Applied Science on YouTube uses his Electron Microscope to compare spinning media. The part of the video that caught my attention is the Vinyl Record. Not only does he show the groove and needle, but he puts it in motion! It’s a great look at how this technology works.

Additionally, I loved how he went into detail about how to prep the record for use in the electron microscope. (Spoiler: he had to make the record and needle conductive.) After the vinyl, he also compares a CD and DVD. The twist is that he also shows how a Capacitance Electronic Disc (CED) compares to the vinyl. You never heard of a CED?

Neil deGrasse Tyson's 4th Nerdist Interview

Thu, 29 Sep 2016 13:17:49 +0000

You are probably familiar with Neil deGrasse Tyson. He is as brilliant as he is entertaining. That fact is why I was so excited when I saw his name pop-up on my queue for the Nerdist Podcast.

Nerdist Podcast

In the past, I suggested some electrical engineering podcasts. The Nerdist isn’t like those. Hosted by Chris Hardwick, each episode includes an interview. As the podcast’s name suggests, most of the guests have some roots in today’s nerd or geek culture. So while not an engineering podcast, there may be the occasional guest that interest you.

Measure PWM Current with a Modified Moving Average

Wed, 28 Sep 2016 13:00:16 +0000

Pulse Width Modulation (PWM) makes it possible to dim lights, control the speed of motors, and (with the help of filters) generate analog reference voltages. When measuring the voltage or current of a PWM signal, there are unique challenges. You can use this tutorial to measure PWM current with a modified moving average (MMA).

As I’ve mentioned in a few posts, I’m working on an RGB LED IoT controller. Soon I’ll post some detailed information on that. In the meantime, one choice I made was to include an INA219 current sensor on the LED power supply. For prototyping, I’m using the Adafruit Breakout Board, but my final design uses the same parts integrated into a custom PCB.

Brushed DC Motor Video Tutorial

Sat, 17 Sep 2016 16:36:39 +0000

How a Brushed DC Motor works and how to use them

This Addohms Electronics Motor Tutorial goes into the third dimension. Using a 3D model, we show what makes a brushed DC motor, well, a “brushed motor.” (Hint: It’s the brushes!) Then, as usual, we break down two simple ways to control them with a microcontroller like the Arduino. You can use a single BJT Transistor (remember those from #10?), build a discrete H-Bridge to go in both directions, or use a popular H-Bridge chip like the L293D or L298D. (Notice the ‘D’!)

Social Media Guide for Engineers, a How-To

Wed, 14 Sep 2016 13:48:45 +0000

Bloomicon / Shutterstock.com

Engineers are notorious introverts. An untrue generalization is that introverts hate being social. Like all humans, introverts are social creatures. We just prefer only to discuss the topics which are of interest to us. We will listen to anything. This social media guide for engineers explains why and how you can participate in social media, without being social.

Let’s address something head-on. Gone are the days of just “here’s what I ate” or “I’m in the bathroom” social posts. Social media channels are mature platforms for communication. Sure, junk still exists. However. You can filter out the signal from the noise when you following my social media guide for engineers.

3D Printer Tips I wish I knew 3 years ago

Wed, 31 Aug 2016 13:00:48 +0000

While I bought my 3D printer a couple of years ago, in March of this year, it only had 75 hours of use. Since March, my counter is over 300 hours. Why? After spending some time doing the right tweaks my printer is printing crazy good. Here are some of my 3D printer tips.

Maybe you’re in the market for a printer, use one at school, get access to one through a maker space, or (like me) used to use yours for a desk ornament, these 3D printer tips are likely to help.

5 Common Arduino Programming Mistakes

Wed, 17 Aug 2016 13:39:41 +0000

Whenever someone sends me some code that doesn’t work, there are a few common Arduino programming mistakes that I check. Some of these mistakes I make myself. In most cases my code will compile just fine. Sometimes, these mistakes won’t generate any compiler error.

When my Arduino code is acting up, these are the first things I check. Here are my 5 common Arduino programming mistakes, I use to debug non-working code.

3 Way Camera Shoe

Thu, 04 Aug 2016 13:29:19 +0000

When recording videos for either baldengineer.com or, more often, AddOhms, I need at least two things attached to my camera. I used a Canon T5i. The two devices I need to have connected are a shotgun microphone and a wireless receiver. In the past, I just let the remote’s wireless receiver dangle. That really bothered me.

I’m still surprised this DSLR shoe adapter didn’t already exist on Thingiverse. Anyway, I created one. Head over to Thingiverse to download it.

Test Equipment Alternatives (Suggested By You!)

Wed, 03 Aug 2016 13:17:55 +0000

A couple of weeks ago, I asked my subscribers for their favorite test equipment alternatives. The reason I asked, was because I recently picked up a Mooshimeter. It is a modern take on the multimeter. However, I will cover that in more detail soon.

While I am fortunate that my bench has the usual equipment like an adjustable power supply, oscilloscope, multimeter, and function generator, I know that not everyone else does. I also had to think back to before I had this equipment, what did I use to troubleshoot my circuits.

Adafruit Temperature Sensor Comparison

Wed, 27 Jul 2016 15:00:32 +0000

Getting back to my IoT projects, I decided to pick up a temperature sensor. While looking through the Adafruit breakout boards, I found they offered nine different digital temperature sensors! This list is in addition to the analog TMP36 temperature sensor, so that’s ten. I needed an Adafruit Temperature Sensor comparison.

With so many options, I quickly found myself getting lost between the various modules. The 10 I found all measured temperature and provided an I2C interface. Except for the MCP9808 board, they all made at least one other type of measurement. The MCP9808 is the cheapest digital temperature sensor breakout that Adafruit offers, and also the most accurate.

IEEE EMC 2016 in Ottawa, ON

Mon, 25 Jul 2016 14:00:42 +0000

The 2016 IEEE International Symposium on Electromagnetic Compatibility is sponsored by, no surprise, the IEEE Electromagnetic Compatibility Society (EMC-S). The EMC Society is the largest organization dedicated to reducing EMI. The society looks at standards, measurements, interference techniques, equipment, and a broad range of other activities.

Previously, I attended the show when it was in North Carolina. A wide variety of information complimented into the deep technical sessions. The vendors on the show floor were varied. I find this to be one of the most technical shows I attend.

Arduboy Review and Hands-On

Wed, 06 Jul 2016 13:00:37 +0000

When it comes to Kickstarters, I have been relatively lucky. Most of the projects I back have shipped, even if years after I forgot. However, few Kickstarters are something I use on a regular basis. The Arduboy has been a pleasant surprise. This Kickstarter-backed project packages the ease of programming an Arduino into a game playing friendly form factor. Here’s my first Arduboy review, impressions and hands-on experience.

Looking back at when I was a kid, there were two gifts I received that made an impact in my life. I have them both to this day: my RadioShack Multimeter and my Nintendo Gameboy. No wonder that my two geek passions have always been electronics and (retro) video games. The Arduboy is a fun little device that combines both! The hardware has the limitations of early 8-bit game machines but the accessibility of an Arduino.

Current Flow Direction

Wed, 22 Jun 2016 13:00:15 +0000

A couple of weeks ago I wrote about four current flow direction myths. As a follow up to that popular post, I decided to dedicate this month’s AddOhms electronics tutorial video to Current Flow. In episode #19, I tackle the question of which way does current flow.

You might have heard about “conventional flow” and “electron flow.” In conventional flow, we assume that current flows from the positive voltage towards the negative voltage. In digital, the “negative voltage” is usually called ground. However, that’s not how the electrons move nor is it how they carry the charge around a circuit path.

Arduino Bootloader, What is it?

Wed, 15 Jun 2016 13:00:14 +0000

Almost all microcontroller (and microprocessor) development systems use some form of a bootloader. Often called firmware, mistakenly, the Arduino bootloader is one example. Since it is a rather popular platform, let’s use it as an example. Let’s talk about what a bootloader does and how it works.

When a microcontroller turns on, it only knows how to do one thing. Typically, that one thing is to run an instruction found at a specific memory location. Often this location address 0x0000, but not always. Usually, this memory location will contain a jump instruction to another place in memory, which is the start of the user program. The bootloader, however, exists in a slightly separate memory space from the user program.

KiCad BOM: Don't Bomb your BOM!

Wed, 08 Jun 2016 13:00:27 +0000

A KiCad BOM is a list of all the parts your design is using. The term BOM, or bill-of-materials, is standard for supply chain management and does not just apply to electronics. KiCad’s eeschema has a BOM export feature. Unfortunately as of Version 4.0, this feature is still somewhat lacking. Given the limitations, here are some tips to take your KiCad BOM from Schematic to Mouser.

Spending a few extra minutes while capturing (drawing) your schematic thinking about your KiCad BOM can save you a ton of time later on. Moreover, as you build up a database of parts, these extra minutes turn into seconds. Here are a couple of ways to describe your parts, especially passive components, better while drawing schematics in KiCad.

They're JUST Capacitors?

Wed, 08 Jun 2016 00:20:22 +0000

I was invited to speak at the 11th Hardware Developers Didactic Galactic group at the Supplyframe office in San Francisco. I talked about the misconception that capacitors are a simple device.

Chris Gammell recorded the discussion and posted it via PHY Media. This video is about 50 minutes.

In this talk, I break down a few things to know about Ceramic, Aluminum, Tantalum, and Supercapacitors. You can see the full video via PHY Media’s YouTube Channel: They’re JUST Capacitors. For links and the slides, check out this post.

6 Electronic Safety Tips I learned while Mountain Climbing

Wed, 18 May 2016 13:00:55 +0000

Electronic safety tips from mountain climbing? Yes! After spending two weeks in Europe for work, I had the chance to spend a weekend with friends in Germany. We hiked up Kampenwand in Bavaria. While working my way through the snow and rocks, I realized mountain climbing safety tips were the same as electronic safety tips. Really! Here’s how.

Grabbing a soldering iron and throwing polarized components around a circuit board is something I often do. So often, I don’t even realize I’m using some of these electronic safety tips. However, a new activity gives you a chance to exercise the safety portion of your brain. Especially when there are no guard rails.

Baldengineer at PCIM 2016

Mon, 09 May 2016 18:56:40 +0000

Do you happen to be around Nuremberg this week? If so, check out the Power Electronics Show, PCIM 2016. I’ll be floating around the show all week. Most of my time I’ll be at KEMET’s booth in building 7. The booth number is 7-302. Just ask for James. You can ask me about capacitors, electronics stuff, or just come to see that I really am bald!

Four Current Flow Myths Addressed

Wed, 27 Apr 2016 14:00:29 +0000

Current flow (direction) is the topic I’m planning for my next AddOhms tutorial. While preparing the script, I started to realize there are some myths or misunderstandings about electricity and current flow.

Ben Franklin Father of Current Flow

Everyone probably knows Ben Franklin. He discovered electricity, of course! Yet, he didn’t. Franklin was the first to prove that lightning was composed of electricity with his famous kite experiment. He was also the first to provide electricity’s well-known labels: positive and negative. And somewhere in there Franklin became famous for “inventing” conventional current flow.

Why do engineers (love to) hate Arduino?

Wed, 20 Apr 2016 13:00:02 +0000

A couple of months ago podcast I listen to interviewed an embedded engineer. Eventually, the topic of Arduino came up, and all three people on the show let of sighs of disgust. This lead to me to start thinking about why do engineers hate Arduino?

On this particular show, they said Arduino had too many abstraction layers to be useful. All three members of the panel agreed that direct hardware access was critical to success in embedded designs.

Top 25 Websites, Tools and Resources for Hardware Startups

Mon, 18 Apr 2016 13:00:45 +0000

Check out John Teel’s Top 25 Websites, Tools and Resources for Hardware Startups. Hardware startups have the unique challenge of having to spend real money, to physical products, with the end product being something … real.

You need all of the help you can get to succeed, which is why John’s list is worth a few minutes. I am familiar with many of the entries but did catch a few new ones. Personally, #9 is my favorite, but I am probably biased.

Switching Voltage Regulator Tutorial

Wed, 13 Apr 2016 13:00:04 +0000

A switching voltage regulator is one of my favorite circuits. In school, they were the first circuits I built where I understood how transistors worked. In fact, they were the first circuit I saw an inductor being useful! Switching regulators are incredibly efficient when designed properly. Of course, this detail about design is important. They are not as simple as a linear regulator, which is basically an IC and two caps.

Hands-on with Arduino Create and Arduino IoT

Wed, 06 Apr 2016 13:00:00 +0000

This past weekend Arduino fans celebrated Arduino and Genuino Day 2016. In classrooms, maker spaces, and impromptu meet-ups around the world enginerds got together to learn and create with Arduino. At the Jacobs Institute for Design Innovation on Berkeley’s Campus, I first heard that Arduino Create had been launched.

In addition to hands-on learning workshops, there was a display of Arduino/Genuino projects by students. In the afternoon, three Arduino co-founders gave a short talk. David Mellis spoke on Machine Learning. Tom Igoe did his first talk on Technology and Humanities. Lastly, Massimo Banzi talked about IoT.

How to Turn Your Arduino Prototype Into a Manufacturable Product

Wed, 30 Mar 2016 14:00:33 +0000

Dreaming of bringing a new hardware product to market? Perhaps you think your product will make the world a better place, or maybe you just dream of making millions of dollars.

Energy Density of 9V battery vs. AA batteries

Wed, 23 Mar 2016 13:00:53 +0000

Previously I wrote up why the 9V battery sucks. As I thought more about that post, I realized, I never explained how much energy is in a 9 V battery versus say a couple of AA batteries.

For this post, I am going to break down the energy stored in a 9 V battery, the small rectangular kind and compare it to what you get with 6 AA batteries. Yes, it takes up a little more space, but you might be surprised by the difference.

Review of The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution

Mon, 14 Mar 2016 13:00:31 +0000

Reading a blog post like this one is something we all do multiple times a day. As early as 20 years ago, such a concept was still entirely unknown to the rest of the world. Walter Isaacson’s “The Innovators…” book is a history telling of the players involved from the early days of Ada Lovelace all the way through to Google’s search success.

Here are some of my favorite highlights from the book.

KEMET Adds AEC-Q200 Capability

Fri, 11 Mar 2016 14:00:47 +0000

Back in December, John Day’s Automotive Electronics Blog featured a post I wrote. The subject was KEMET’s (then) recent Automotive product introductions. Here’s a summary of the article.

KEMET has been working hard to meet the needs of automotive engineers in recent months. These efforts have resulted in several technology developments that will be of particular interest to design engineers involved with automotive electronic systems.

Firstly, the company made several key developments in polymer electrolytic capacitor technology. Recent additions to their high-voltage MLCC’s ArcShield line include new automotive grade parts rated for >500V and an X2-Rated Film capacitor that passes AEC-Q200’s qualification guidelines as well.

Chuck Norris On Pull-Up Resistors

Fri, 11 Mar 2016 06:51:18 +0000

Think you can do without Pull-Up Resistors? Only Chuck Norris doesn’t need them.

Logic Analyzer Tutorial and Introduction

Wed, 09 Mar 2016 16:00:17 +0000

A DMM, or multimeter, is the go-to instrument for debugging most circuits. You probably already have at least one DMM on your bench for this reason. Me? I have three. But that’s a different story. Let’s talk about a Logic Analyzer.

Digital signals represent two states: on (usually “1”) and off (usually “0”). A multimeter (DMM) may be of limited value for these signals. When using the DC voltage measurement, you can see “something” is happening, but not exactly what that “something” is. For example on a PWM pin, you’ll see the RMS Voltage change as you modify the duty cycle. However, you can not see if the signal is “ringing” when turning on and off.

Arduino to ESP8266, 5 reasons to switch

Wed, 02 Mar 2016 16:00:04 +0000

A couple of weeks ago I posted four things to know about the ESP8266 before using one. The biggest surprise from that post is people seem to think I do not like the ESP8266! This idea is not the case; the ESP8266 is awesome. I like them so much that my Adafruit Feather HUZZAH with ESP8266 has become my go-to Arduino board.

Wait what? James uses something other than Arduino? Yes, I do! I have many different boards and have used most of them for one task or another.

MQTT Tutorial for Raspberry Pi, Arduino, and ESP8266

Wed, 24 Feb 2016 16:00:45 +0000

This week’s MQTT Tutorial connects a Raspberry Pi, ESP8266 (or Arduino), and a PC together. Remember last week’s post provided an overview of message brokers and MQTT. We learned that MQTT is a hub and spoke protocol for sending messages between IoT devices. Clients can subscribe or publish messages to a central server, called a broker.

Now it’s time to connect our IoT devices together!

For this MQTT tutorial, I have three main elements:
• My Computer, which will act as the broker.
• Raspberry Pi running Python
• ESP8266 controlling an LED

Hardware Developers Didactic Galactic 0xb: Capacitors (HDDG11)

Fri, 19 Feb 2016 01:39:45 +0000

Hardware Developers Didactic Galactic is a group for hardware designers, hackers, and enthusiasts to discuss hardware-related topics. HDDG11 (or 0xb) featured a presentation from SnapEDA CEO on Footprints and my presentation on Capacitors.

Titled “They’re JUST capacitors?” I used content from my time as a KEMET Field Application Engineer.

Overview

In the presentation, I address the common myth or guideline: “capacitors should be derated 50%.” Comparing Aluminum, Ceramic, and Tantalum we discuss why each technology has a de-rating associated with it. Turns out, they all have different reasons to de-rate.

MQTT Introduction and Tutorial Part One

Wed, 17 Feb 2016 16:00:25 +0000

MQTT is an easy way for Internet of Things (IoT) devices to communicate with each other. This light-weight protocol can be used with a simple 8-bit Arduino to a Raspberry Pi to a multi-core PC to Amazon Web Services. It is that versatile.

This MQTT Tutorial is broken into two parts. Part one is an MQTT Introduction. You’ll understand how publish/subscribe message brokering works. Next week, Part two will be a tutorial on using MQTT to communicate between a PC, Raspberry Pi, and ESP8266.

HDDG #11 - Capacitors and Footprints

Mon, 15 Feb 2016 22:48:06 +0000

Super excited that I’ll be speaking at this month’s Hardware Developers Didactic Galactic (HDDG) #11. The meetup is on Thursday, February 18, 2016. It should come as no surprise that I’ll be talking about capacitors–something I have a bit of experience on.

Also presenting will be SnapEDA CEO’s Natasha Baker. I’ve written about SnapEDA in the past post, How to find Parts for your Electronics.

One reason to come is just to see what the Hackaday / Supplyframe office looks like!

Raspberry Pi GUI Tutorial

Wed, 03 Feb 2016 17:58:53 +0000

My favorite Raspberry Pi add-on is the PiTFT from Adafruit. With it, you easily get a Raspberry Pi GUI interface and touch screen. The PiTFT software install is just a few things and it is good to go.

Adafruit PiTFT - Click for more info

This screen is what I needed for my IoT project. The Pi+Screen will act as the primary controller for all of my things. The problem is I didn’t know much about writing GUI applications in Linux. So what could I do to create a Raspberry Pi GUI?

Full Size LEGO BB-8 time lapse build by Bright Bricks

Tue, 02 Feb 2016 19:00:23 +0000

Quick timelapse video of Bright Bricks building a life-size BB-8 unit. Surprising to me was that I always imagined these builds solid with LEGO pieces. Turns out, they are built an internal structure, which makes more sense really. Either way, watching this short LEGO BB-8 build is fun.

IoT: Internet Of Nothing

Thu, 28 Jan 2016 14:00:44 +0000

IoT (n): Internet of Things

Things that connect with the internet, to share information.
Devices that communicate with each other.
1. No wait. Nothing does. It’s the Internet Of Nothing!

It continues to amaze me how few Internet of Things (IoT) devices actually communicate with each other. Isn’t Internet connectivity suppose to make it EASIER for things to talk? Computers have been communicating with the Internet for 45 years. Why can’t Light Bulbs from two manufacturers do it?

Use Arduino millis() with buttons to delay events

Wed, 27 Jan 2016 16:00:16 +0000

One of the common questions related to using the millis() function in Arduino, is around timed events. After an event occurs, you want the code to wait for some time before doing the next step. But you don’t want to stop the program with delay().

In this example, we will use millis() to wait a few seconds after a pushbutton press to turn on an LED. Then a few seconds later, we will turn it off. All without using delay().

Bald Engineer's Top 2015 Stuff

Wed, 30 Dec 2015 16:00:33 +0000

As 2015 wraps up, I took a look at baldengineer.com’s traffic for the past year. Here’s some of the most popular stuff from my blog, in case you missed it.

Everyone with a blog looks at their traffic numbers. For me, traffic data provides feedback on what tutorials or posts are helping people most. Each year, the traffic to my blog grows at ridiculous numbers. As someone with both an engineering and marketing background, I find the numbers impossible to believe.

Is the Raspberry Pi Zero worth $5?

Wed, 16 Dec 2015 16:00:57 +0000

What makes the Raspberry Pi so attractive? At $35 it is an unbelievable value for a single board computer. Since its introduction, a price race to the bottom has begun.

The C.H.I.P. claims to have started shipping the $9 computer. Which, many pointed out, doesn’t cost $9 once you add things like support for display. I would like to point out, I was an early backer and have yet to receive one.

Getting PCBs from KiCad to X-Carve

Wed, 09 Dec 2015 16:00:27 +0000

The last time I looked at using an X-Carve for Printed Circuit Boards (PCBs), I created a demo board with EAGLE. Since then, I have learned more about using KiCad, the open source electronics CAD suite. While not a step-by-step tutorial, here is my rough KiCad to X-Carve PCB workflow. These are just the high-level steps, the tools necessary, and the settings I’ve discovered for each—so far.

Eventually, I will make this a more detailed KiCad to X-Carve PCB tutorial, so make sure you subscribe to my RSS feed for updates.

Need a G-code Viewer? Check out this Open Source CAM Simulator

Mon, 07 Dec 2015 16:00:39 +0000

A gCode viewer is essential when doing anything with a CNC. Knowing where the tools is going to run can mean the different between a failed cut and a broken bit. Or let’s say you’re trying to debug some gCode scripting, no need to wait an hour to find out you messed something up. That’s where a GCode Viewer can help.

There are several on-line options that let you upload files and see them in a 3D view. However, if your CNC is setup like mine, there isn’t a good internet connection available. Camotics, formerly the unfortunately named OpenSCAM, is a cross-platform open source gCode viewer / simulator.

Four ESP8266 Gotchas and a tip for a first time users

Wed, 02 Dec 2015 16:00:13 +0000

Adding WiFi to any project can be difficult. There are a few off the shelf options that make it easier. One option is the official Arduino WiFi shield. This full-featured shield uses its integrated microcontroller to handle the WiFi protocol, security, and the TCP/IP stack for you. From “plug it in and go” perspective, this is an awesome option for Arduino-based projects. Plenty of example code supports the nicely designed hardware. The main downside to some people is the price.

2015 Holiday Gift Guide

Wed, 25 Nov 2015 16:00:49 +0000

This week marks the start of the 2015 Holiday Shopping Season. Being a short week for me, I thought I’d offer up some gift suggestions for engineers.

Being the only engineer in my immediate family, gift giving time is always interesting. Many times I wished I could give them a list of unusual items, without saying “here buy these.”

Whether you want to gift something to a fellow electronics enginerd or you to offer your family some suggestions, there is something on this list.

The Martian

Fri, 13 Nov 2015 07:30:47 +0000

The Martian by Andy Weir is an engineer’s dream story. The story opens with Mark Watney being stranded on Mars after an accident occurs. The book is a collection of his daily logs on the Martian surface, chronicling the measures he takes to stay alive.

Rarely do I read a fiction book so well thought out, I start solving the problems along with the characters. Midway through I was excited because I would see Mark’s solution as one of the possible answers in my head. I also found myself invested in what happens to Mark. He is a likeable guy and, at least for me, easily relatable.

Difference between Programming and Native Ports

Wed, 11 Nov 2015 16:00:04 +0000

When you hear the name “Arduino,” does a picture of the Uno come to mind? While the most popular, this 8-bit based board isn’t the only Arduino available today. There are some other boards available like the Due and recently introduced Zero, which are far more advanced than the humble Uno.

These are 32-bit microcontroller boards that have a very different architecture compared to the relatively straightforward Uno. In fact, one of the most striking differences is that the Due and Zero have two USB ports.

Build a proper R-2R DAC

Fri, 06 Nov 2015 16:10:58 +0000

Creating real analog outputs from a digital pin is possible when you use an R-2R DAC. What is a DAC? The letters stand for D igital to A nalog C onverter. This simple DAC is built using resistor. The principle works on voltage dividers. By enabling different combinations of resistors, it is possible to get various voltage levels.

Obviously, such a simple design will have some trade-offs.

FleaFPGA Introduction

Wed, 04 Nov 2015 17:00:09 +0000

Can’t find the digital chip you need on Mouser or just wish you could make it yourself? With the FleaFPGA board, you can! As a college freshman, we heard rumors of a custom Integrated Circuit (IC) class. Surely what had to be a senior level class, I couldn’t wait until I understood electrical engineering enough that I got to make my own IC!

Two years passed, I was learning Verilog and VHDL in a class titled “Complex Programmable Logic Devices.” In short, CPLD. Those devices were the precursors to today’s modern FPGA devices.

Learn the basics of Acrylic

Tue, 03 Nov 2015 14:00:21 +0000

One of the most popular materials to use with a laser cutter is acrylic. Head over to buy some acrylic from Inventables and you’ll see options for “extruded” or “cast” types. Not sure what that means?

This Make Skill Builder on Acrylic gives the basics on the material. You’ll understand the differences between the two: especially important if you plan to mill or laser cut it. Additionally, there are tips for bending, shaping, and gluing acrylic.

A Whole New Engineer

Mon, 02 Nov 2015 18:38:30 +0000

A couple of weeks ago I was invited to join The Engineering Commons podcast to talk about capacitors on episode 93. I had been a listener of the podcast because I heard about it in this book. A Whole New Engineer looks at the changes are needed in engineering education. My personal interest was to see if there were elements I could apply to the AddOhms Electronics Tutorials I create. Like all aspects of our lives, evoluation is occuring and educaiton is no different. On top of that, traditional education techniques rarely prepare students for live after school.

The Isolated Engineer

Wed, 28 Oct 2015 16:00:27 +0000

James and I were talking over e-mail the other day, and he said that he felt isolated living in South Florida. Isolated? You should try living in South Africa, James - Then you’ll know what isolation is!

Learn the difference between laser types

Tue, 27 Oct 2015 13:39:39 +0000

inside a laser diode

One of the most versatile tools in a shop or makerspace is a laser cutter. The recently funded Glowforge makes having one in your garage a possibility.

With so much exciting around laser cutters, you might be wonder what is a laser anyway? There are two primary laser types: Gas and Diode. Jordan Bunker goes into detail in the Make: Skill Builder article, about the difference.

Print your own Graph Paper

Mon, 26 Oct 2015 13:00:54 +0000

Ever need graph paper for a project, but can’t wait for Amazon Prime? No problem, this free online tool lets you generate graph paper on the fly. Multiple types of graph lines are available and each are fully configurable. Once done, you get a clean PDF of graph paper to print.

Here’s a short run-down of the graph paper types available:

Squares
Triangle and Hexagons
Circular and Polar (Think Smith Chart)
Asymmetric
Note Taking

Check out the free graph paper generator at incompetech.com.

Proper Larson Scanner with Software PWM (Repost)

Wed, 21 Oct 2015 16:00:03 +0000

Last week I had a detailed Arduino tutorial on software pulse width modulation using millis() and micros(). Why? Because I wanted to create a Proper Larson Scanner, with persistence and at least 8 LEDs.

KITT larson scanner example

Even though it is a popular project for the Arduino Uno, most Larson scanner tutorials, like my first one, have a few flaws. First, there is no persistence, or tail, to the LED as it moves back and forth. Persistence could be solved by using pulse-width-modulation. The Uno and other 328p-based micros only have 6 Pulse Width Modulation (PWM) pins. And let’s be honest, every project is made better by adding more LEDs. :)

Additive Manufacturing (aka 3D Printing) Infographic

Tue, 20 Oct 2015 13:00:47 +0000

While I was attending a material science conference, I learned the value of listening to something new. The paper I came to see was finished, and the next was about to start. It was titled, “Additive Manufacturing.”

I almost left!

What a dull phrase, right? Well, I was stuck in the middle of a row with four people on either side of me. So I decided, it was a good time to catch up on Reddit. What I didn’t realize is “additive manufacturing” is what almost everyone else in the world calls “3D Printing.” Plus, this presenter was talking about doing it with metal!

Capacitor Interview on The Engineering Commons Podcast

Tue, 20 Oct 2015 02:08:10 +0000

The awesome hosts on The Engineering Commons (TEC) podcast asked me to join them on Episode 93-Capacitors! They told me I was the first passive component expert they had on their shown. It was a blast talking to Jeff, Carmen, Brian, and Adam.

The unique thing, in my opinion, about The Engineering Commons is that it covers multiple engineering disciplines. A couple of episodes ago, they talked traffic. Since I am about to move, the episode on Garage Setups was great.

Huge archive from Project Apollo now on Flickr

Fri, 09 Oct 2015 13:00:49 +0000

moon from apollo project archive

Years of hard work, curation, and archiving have brought the Project Apollo Photo Archive to a Flickr album. Kipp Teague writes,

“This new Flickr gallery would have not been possible without the support of Mike [Gentry], Steve [Garber], and Eric [Jones], and many others.”

In this note, he corrects a misconception that this archive itself was an NASA undertaking. While the photos come from NASA, the archive is an independent effort.

The War On Science - AsapSCIENCE

Thu, 08 Oct 2015 23:41:42 +0000

The latest video from AsapSCIENCE, The War on Science, addresses the preverbal war between science and society we are experiencing today. 100, 200, or 1000+ years ago you could argue the ignorance of science was due to lack of information availability. However, that does not apply to today’s world. The entire World’s knowledge and the sum of collected data are available to virtually anyone, anywhere at any time. This moment isn’t just historical; it is pivotal. Yet. Society as a whole seems to continue the trend of ignoring this data in favor of emotional social media posts.

Elegant and cheap storage solutions for your shop

Thu, 08 Oct 2015 13:00:04 +0000

lattice as shop storage

The article caught my eye because I’m about to make a move, and I’ll be setting up my shop soon. Seeing these clever alternate uses is already giving me some ideas.

The perfect shop doesn’t need expensive storage options. While there are stores dedicated to containers, they to tend to run on the expensive side. A workshop, may not need the most expensive storage gear. Especially if it gets as dusty as mine! This Make article offers 5 Simple Shop Storage Solutions.

Arduino Software PWM with millis()

Wed, 07 Oct 2015 13:00:04 +0000

The Arduino Uno has six pins dedicated to Pulse Width Modulation (PWM). PWM is great for analog-like control for the speed of motors or LED fading. But what if you want to control more than 6 devices? Or what if you’re using the PWM pins to control servo motors, but still want to fade an LED on a 7th pin?

One option is to change boards and processors. For example, you could move up to the Arduino Mega 2560. That means a bigger board and more cost.

How Arduino digitalWrite Works – and why AVR is Faster

Mon, 05 Oct 2015 13:00:18 +0000

Previously I looked at the speed difference between digitalWrite and direct port manipulation. It was a chance to check out a Saleae Logic Analyzer. Andrew at !Crash-Bang Prototyping took the analysis a step further. He broke down what is going on inside of digitalWrite().

This study is useful. When you’re ready to move beyond the Arduino IDE or the core functions, you can decide if you need your own version of digitalWrite().

Build your own Ghostbusters Trap

Fri, 02 Oct 2015 13:00:19 +0000

Deck out the rest of your Ghostbuster gear with a Ghost Trap. Dustin McLean from DIY Prop Shop from AWE me builds a trap in this quick 12-minute video. The build uses very basic materials: cardboard, popsicle sticks, tape, PVC, and spray paint. Of course, the tools used are just basic cutting and straight edges.

If you aren’t familiar with DIY Prop Shop, the show–as the name suggests–takes a DIY approach to building famous movie props. Totally fun to watch and get ideas for your projects.

EngineerDog explains why stressed plastic turns white

Thu, 01 Oct 2015 13:00:51 +0000

Polymer Crazing via engineerdog.com

Ever notice when you over-stress plastic, the stress points tend to turn white? The color or type of plastic doesn’t seem to matter, does it? So what is going on? This awesome post from EngineerDog explains why stressed plastic turns white.

If you’re starting to work with ABS on your 3d printer, it will help to understand what is happening to the polymer chains. It’s a process called crazing.

My Modular Soldering Station for the Space Limited

Wed, 30 Sep 2015 13:00:06 +0000

Solder is the glue of electronic circuits. In addition to a permanent mechanical connection, solder provides an electrical connection. Not too much unlike glue solder combines two separate metal pieces with a bonding material. In this case, the bonding material is a metal or allow with a relatively low melting point.

When soldering together a circuit, the quality of the solder joint is crucial. Most people probably recognize the need for a high-quality soldering iron, like the FX-888D from Hakko, but about the other tools?

Capacitor reliability can be improved with the right materials

Tue, 29 Sep 2015 22:52:52 +0000

Capacitor lifetime depends on the materials

Although not all applications are safety critical or mission critical, reliability is still a vital consideration for many electronic products. Making informed choices at the part selection stage can help ensure the product will perform correctly over its intended lifetime.

When choosing capacitors, properties such as volumetric efficiency, frequency stability, temperature rating or equivalent series resistance are often the primary factors that govern technology choice. In these cases, understanding factors affecting lifetime can help engineers make sure the product will deliver the required reliability.

Corner Case: 90-deg turns for WS2812

Tue, 29 Sep 2015 13:00:34 +0000

NeoCorner from josh.com

If you’re working with the WS2812B and need to turn corners, you’ll want to check out this NeoPixel Corner adapter PCB from josh.com. It’s a pretty simple board. I came across it as a solution for an upcoming lighting project.

In josh’s example, he used a CNC to mill the PCBs. If you’re using one-sided FR4, that might work well. You’ll want to double-check thicknesses if you want to use OSHPark or similar.

Makers keep your eyes out for these 8 "Trash" Types

Mon, 28 Sep 2015 13:00:48 +0000

Dumpster diving can be a rewarding experience for a maker. You never know what components you might be able to recover from electronics otherwise discarded. What can be hidden inside of an “obsolete” box? Motors? Sensors? Capacitors?

Older technologies like VCRs and Scanners can be a treasure trove of stepper and servo motors. Under-powered, by today’s standards, computers probably have cables that can be re-purposed into your current project.

Cool learning resource: KEMET Engineering Center

Wed, 16 Sep 2015 13:00:21 +0000

Whether you are an engineer with enough experience to be called a graybeard or a novice that keeps grabbing the wrong end of a soldering iron, there is one component that eludes everyone working in electronics.

It’s the humble capacitor.

A seemingly simple device, turns out, to be incredibly complex. While the basic electrode-dielectric-electrode structure sounds simple, the materials used in that structure drastically changes the characteristics of the device.

KEMET Engineering Center Screenshot, Courtesy of KEMET Corporation.

Review of EMSL's XL741

Thu, 03 Sep 2015 01:25:09 +0000

When you need to buffer the output of an R-2R ladder or an RC filtered PWM signal, an op-amp is a single chip option. Unlike a discrete NPN transistor like a 2n3904, there is a lot going on inside of an LM741—or any op amp for that matter.

What if you could look inside of the op-amp? Wouldn’t it be cool to see how many transistors make up these small chips?

Periscope demo: Pros and Con

Thu, 20 Aug 2015 13:00:41 +0000

After fighting bugs, bad connections, and burned out chips your project is working–or even done. The next step? Record a video, edit it, and upload it to YouTube.

Too many steps? Then maybe you just want to do a Periscope demo. Within seconds, you can be broadcasting your project to the world.

This past weekend I tried my first couple of scopes. The first Periscope “demo” was me soldering together a Three Fives from Evil Mad Scientist Labs. The others periscope demos were 3d printing related.

Circuit Trading Cards Review

Wed, 12 Aug 2015 13:00:18 +0000

One of my early hobbies as a kid was collecting baseball cards. At every card show, I was on the lookout for the 1989 Ken Griffey Jr Rookie card, #1, from Topps.My collecting craze lasted until the baseball strike in 1994. Then I lost interest in professional baseball and its collectibles.

You’re asking, what does this have to do with electronics? Well, the Circuit Trading Cards from Arachnid Labs reminds me of the days I spent trading baseball cards. Instead of memorizing RBIs and Homerun counts, these circuit patterns trading cards teach you circuit basics.

AddOhms #15: Pull-Up Resistors (and buttons)

Mon, 10 Aug 2015 13:00:05 +0000

The latest AddOhms looks at why you need a pull-up resistor when using push-buttons. This video goes into what happens when you leave a pin floating, what a floating pin means, and how the pull-up works. You can get more information about the video on the AddOhms Episode page.

Pull-Up Resistors can be a difficult topic to understand. That’s why I made this video.

This tutorial is the 2nd time I’ve made a video on pull-ups. Despite being a single resistor, it can be a difficult topic for new hardware designers to understand. The pull-up video was the first video tutorial I ever made. In fact, the YouTube version uses YouTube’s “stabilization” algorithm, which gives the video a very warped feel.

Blink without delay() explained line-by-line

Wed, 05 Aug 2015 13:00:27 +0000

Making the move to millis()-based code can be daunting. You have to rethink your logic, implement flags, program a state machine — and more importantly, start using millis(). Generally in forums and on IRC people will just point to the “blink without delay” example, hoping the commented code is enough for a new user. It’s not enough.

I have a growing list of millis()-based tasks posted in my millis() cookbook. But sometimes that those examples might be too simple or not close enough to your project’s end target. That got me thinking about different ways to help explain how millis() works. I thought “wow, you need to understand every line of an example” which leads me to: line-by-line.

Microcontroller state machine with enum tutorial

Wed, 29 Jul 2015 13:00:07 +0000

Flag variables are great, and totally not evil, when you just have two states: ON or OFF. What about when you have multiple states? Is there an option better than creating multiple flag variables?

The C-language has a declaration type just for this purpose. It is called an enumeration, or enum.

Setting up a state machine with enum is a surprisingly simple. Arduino and embedded programmers should use them!

All you need to do is create descriptive tag names, and let the compiler assign them an integer value. Unlike a #define which is just a macro replacement, the compiler treats an enum as your personal variable type.

Benchmarking Arduino's digitalWrite() with a Logic Analyzer

Wed, 22 Jul 2015 13:00:55 +0000

Recently I picked up a device called Logic from Saleae. It’s a 4-channel USB-based logic analyzer. While learning how the simple, but effective, UI works I ran some timing benchmarks on my Arduino Uno. The subject? digitalWrite(). I wanted to know how fastdigitalWrite() could turn on two (or more) pins.

Almost all Arduino users start out with the simple “blink” sketch. Turn pin 13 ON, delay, turn it OFF, and delay again. The heart of this version of “Hello World!” is the digitalWrite() function. Many Arduino users never even think about all of the stuff this single function call hides.

Engineers

Fri, 17 Jul 2015 13:00:02 +0000

Found this one while going through some old files. One of my favorite volunteering activities is introducing kids to engineering. After judging a FIRST competition, I learned about Central Texas Discover Engineering. They had a program that gave me a chance to spend an entire day talking to middle school kids about engineering.

I started the class with a simple question: “What do engineers do? Surprisingly, most of the kids answered pretty well. Then I went through these slides to give them an idea of other types of engineers. Lastly, we did a fun “engineering” activity.

Flag variables are not evil (for Microcontrollers)

Wed, 15 Jul 2015 13:00:13 +0000

Getting programming questions answered on the internet can be problematic. Programmers love to have opinions, stick to those ideas, and express them to you even when their opinion has nothing to do with your question(s).

Not only am I going to explain how to use flag variables in your code, I am going to encourage their use—which most programmers avoid.

However, this advice comes with two caveats.

This information only applies to limited resource environments like an Arduino, LaunchPad or PIC.
Use flag variables very carefully when you do use them.

The following flag variable usage examples are Arduino-centric but apply to any microcontroller platform, including the Energia project for TI Launchpads.> Flag variables are a Good Thing(tm) – when used properly

P-Channel MOSFET Tutorial with only Positive Voltages

Thu, 09 Jul 2015 01:20:55 +0000

On every page of my blog, you might notice a chat window. If I’m not busy, we can chat in real-time. If not, the messages come to me by email. Here’s one I got from Matt the other day:

Let’s talk a bit about how (and why) you would use a P-Channel MOSFET. Matt, and he’s not the only one, is probably asking this question based on the “myth” that P-Channel MOSFETs require “negative voltage” supplies.

Which Arduino Starter Kit is the Best?

Wed, 01 Jul 2015 13:00:33 +0000

The other day my friend called me up. He told me how much he missed building circuits and wanted to start again with the Arduino.

So he asked me “which Arduino starter kit is the best to buy?” At which point, I drew a long breath. Easy question, not always an easy answer.

Picking out an electronics kit depends on a number of factors. You should consider:

Your budget
What you already have
What you want to do

#1 and #2 are probably pretty easy to figure out. For many beginners, it’s “not much” and “nothing.” When you don’t know #3, what you want to do, then it gets trickier. Coming back to my friend, what did I do? Well, I went out and bought each one of the kits in this post. I put myself in his shoes and maybe these are your shoes as well.

Check out the 240p Test Suite

Mon, 29 Jun 2015 14:00:29 +0000

Learned about it in this video from the YouTube Channel My Life in Gaming. Some of their videos are a bit more technical than the general “retro review” style, which is why I started watching.

In their RGB 300 Video Series, they covered a homebrew project called “240p Test Suite.”

This project includes a number of test graphics and patterns to help in adjusting the settings of a modern TV. Even more impressive are the systems it covers:

The Bernoulli Box - Where Physics Met Storage

Thu, 25 Jun 2015 06:30:11 +0000

Back in the 1990s, a 1.44mb floppy disk was a reasonable storage size for most documents. For bigger documents or backing up an internal hard drive, other options were necessary. You might remember the Zip Drive, but that wasn’t the first large portable media.

The Bernoulli Box was the precursor to the Zip Drive. It used custom media that could store 10s to 100mbs on portable disks. Well, portable compared to carrying around an entire hard drive. Operating using the Bernoulli principal, the drive’s head never comes in contact with the “floppy” material inside the protective case.

How to find parts for your electronics projects and designs

Wed, 24 Jun 2015 13:00:58 +0000

What part is the most important part in building a project? All of them! Okay, bad joke. Selecting the right parts or components for a design is an area where both new hobbyist and veteran engineers struggle. The wide variety of devices make it almost impossible to know if you are selecting the right one.

Looking at a curated List, using component search engines and browsing DIY shops are how I tend to find parts for my projects.

Machine Learning with Super Mario Brothers

Mon, 22 Jun 2015 14:00:02 +0000

Using a learning algorithm known as NEAT, this Super Mario World play through is an example of a machine learning how to beat the level on its own. Using an evolutionary process, a neural network was built–or learned–to complete the level. The name of the program used to control Mario is called… Mar-I/O.

N: Neuro
E: Evolution of
A: Augmenting
T: Topologies

The initial play through is fascinating as well as the breakdown of what is going on. Well worth the 5 minutes.

Control a Rigol Scope with Linux

Sat, 20 Jun 2015 22:11:03 +0000

The Rigol DS1052E digital oscilloscopes are very popular for both hobbyist and professional engineers. These are very affordable scopes that pack a lot of value. Most of the software tools offered from Rigol only run on Windows. Al Williams has fixed that with the the qrigol project on GitHub.

From the readme file:

Uses USB communications with Scope
Allows keyboard to be unlocked so you can use both the panel and the software
Allows easy reading of all measurements as well as logging of all measurements
Control of common scope functions
Saves waveforms in CSV format
Integrates with external plot software like gnuplot to qtiplot
Diagnostic mode to send raw commands to scope

There’s a couple of limitations, but I want to draw attention to one. If your region uses a comma (",") as a decimal point, you might run into issues. For more information, you might want to check out the qrigol thread on the EEVBlog.

X-Carve CNC Review and Hands-On with PCB Milling

Wed, 10 Jun 2015 14:00:07 +0000

There are two methods to making a prototype PCB: 1) Etch Your Own or 2) Send to a Prototyping Service. While there are many prototyping service options, most cause you to wait anywhere between 24 hours and 30 days before you get your boards back.

If you need a PCB done today, etching at home is a great option. Chemical etching involves all kinds of steps with all kinds of weird chemicals. If you don’t want your neighbors to think you’re the next Walter White, then mechanical etching is a better option. Which is why I bought an X-Carve from Inventables. It’s a CNC Milling Kit you build yourself.

How do you remove Jitter from a signal?

Fri, 05 Jun 2015 14:00:00 +0000

Use de-caffeinated Silicon, of course!

Get electronics help with the right question

Wed, 03 Jun 2015 14:00:03 +0000

4 keys to getting electronics help for your project

When describing a person, do you ever use the phrase “their strength is their weakness?” That’s how I feel about Internet forums. The strength of forums is the collective knowledge of like-minded people, some with more experience than others. Sadly, that is also the weakness of Internet forums… Whether it is a topic-specific site like the EEVBlog Forum or an almost anything site like Reddit the strength/weakness holds true.

What's the difference between Series and Parallel Circuits?

Wed, 27 May 2015 14:00:28 +0000

Tutorial on schematics basics

The funny thing about schematics is that they are much easier to draw than they are to read. There are many common circuits. When an experienced engineer looks at them, it’s like a second language. When someone less experienced looks at them, it looks like random lines and symbols thrown together at the last-minute. (Or maybe that’s just the schematics *I* draw.)

Other than reading Schematic Symbols themselves, one of the basic skill necessary to read a schematic is recognizing series and parallel circuits.

Add wireless with one of these five wireless modules

Wed, 20 May 2015 14:00:07 +0000

Your IoT project needs one of these wireless modules

Getting your project connected to the internet is relatively easy these days. Here are five off the shelf modules that will easily add wireless to your project.

Back when I was in school, I remember spending an entire semester making a RF amplifier board. In fact, I had to use a pencil eraser to remove oxidation on the copper traces to remove an unwanted oscillation, caused by the impedance mismatch of the oxidation on the copper traces. Talk about tough.

DIY Battery Powered Apple Watch Charger

Mon, 18 May 2015 14:00:49 +0000

Apple Watch Charger on Thingiverse

Using an Adafruit Charger Board, a cut-up magnetic Apple Watch Charger cable and some 3d printing, guypl has created a DIY battery-powered charger for the Apple Watch.

The cool thing about the design is that the 2000mAh battery he used, can be recharged with a standard micro USB cable. As someone who travels often, this setup is ideal for me. One less cable to carry and a self-contained charger for the Apple Watch.

Pushbutton and Flashing LED tutorial with millis()

Wed, 06 May 2015 14:00:21 +0000

How to blink (or flash) a LED without delay() and detect button pushes

One of the limitations of the delay() function is that nothing else can really be done. This presents a problem when you want to flash a LED while waiting for a pushbutton to be pressed.

Flashing the LED with millis() and using a flag variable to find if the LED should be flashing solves this problem.

Consider this another example to my virtual millis() cookbook.

Cutting Perfect Breadboard Jumper Wires

Fri, 01 May 2015 14:00:22 +0000

Learning to a breadboard is critical when adding electronics to a project. A skill often overlooked is how to use breadboard jumper wires correctly. For example, when I breadboard a circuit I only use Red, Green, or Blue for positive voltages and Black for ground. Other colors, it depends on the functions of the wire. The idea is to keep it clear when I look at the board, what each wire is doing.

Five ways to make a schematic (quickly)

Wed, 29 Apr 2015 14:00:37 +0000

Engineers make a schematic to explain their circuits.

One time I was looking for a non-tourist pub in Japan. I asked someone for help. She said, “I’m sorry, but I do not speak good English. I will bring my friend, and she will draw you a map.” (Exact quote!) The map her friend drew, gave directions to a bar with a “Neon Yellow Sing.” She meant “sign.”

Learn Arduino Programming

Mon, 27 Apr 2015 14:00:49 +0000

When learning to use an Arduino, you have two things to learn: programming and hardware. In the past, I’ve taught some classes on how to program the Arduino. These are the slides I used to explain what the Arduino “Language” is, basic debugging concepts, how to use variables, and basic structures.

Getting started with Energia and the MSP430

Mon, 27 Apr 2015 14:00:16 +0000

An Open Source IDE for TI’s line of MSP430-based boards. Based on the same software as the Arduino project, Energia brings easy of use to an awesome family of microcontrollers.

Apple ][ Watch and It is Real

Fri, 24 Apr 2015 14:00:40 +0000

Today “regular” people will start receiving their pre-ordered Apple Watch. Whether they spent $350 or over $10,000 dollars, they’ll now have a device that connects to their iPhone and tells time. Like their iPhone does. But with Bluetooth!

What if you don’t want an Apple watch, but want to celebrate a real computing achievement? Check out this video on an Apple ][ watch. Oh and it is real.

That’s right, this isn’t just some clever movie-magic hoax. Following this Instructable, you can build your own Apple ][ Watch.

Energia and MSP430: Arduino Alternative

Wed, 22 Apr 2015 14:00:49 +0000

Does Energia stack up as one of the Arduino alternatives?

With all the recent noise around Arduino LLC and Arduino SRL, I felt like I needed a break from Arduino. So I decided to come back to a platform I set aside a while ago: TI’s MSP430.

Previously I wrote it off because of the Windows-centric software. In fact, I made my first “review” video based on it. (I’m a Mac / Linux guy.)

Arduino pinMode on Analog Inputs

Mon, 20 Apr 2015 14:00:50 +0000

All Arduino boards contain analog and digital pins. The Arduino functions have different calls depending on the pin type. For example, when calling analogRead(), an analog input pin is automatically changed from a digital input (or output) into an analog input. For this reason, it isn’t necessary to call the pinMode function on the pin. However, when I write Arduino Sketches, I still put a pinMode(A0, INPUT) in setup anyway.

An Open Letter to Arduino LLC and Arduino SRL #OneArduino

Fri, 10 Apr 2015 13:00:31 +0000

Most of the major electronic blogs have covered the controversy between Arduino LLC and Arduino SRL. My first deep look into it was from Hackaday’s Arduino v. Arduino. Since it has been covered so well by others, I won’t re-hash the already known facts.

If you want to join in giving feedback to these companies, please tag your posts, tweets, and content with " #OneArduino".

Don't be afraid of learning a new tool

Wed, 08 Apr 2015 14:07:13 +0000

Behind-The-Scenes of AddOhms #14

After moving from learning a new tool to mastery, the resistance for me to switch becomes very high. This can apply to hardware tools like a drill, saw or CNC milling machine. It can also apply to software tools like EAGLE, Programming Languages or video editing software. In AddOhms #14, I gave an overview of the VirtualBench from National Instruments which I’ve covered on this blog as a hands-on, written review and video review.

Can a 1µF decoupling capacitor be too much?

Wed, 01 Apr 2015 14:06:12 +0000

To save time, breadboard pins or just lack of knowledge people try to skip adding even one decoupling capacitor to a circuit. Either on IRC or in Forums you can almost always see it coming: “randomly, my circuit stops working” And then, “what do you mean a decoupling capacitor?” question.

While working on breadboard Arduino, I came across some unexpected measurements. Initially, the only capacitors on the breadboard were the two 22pF from crystal to ground and the capacitor connected to RESET for Auto-RESET.

Case Study in Optimization: Faster SPI on AVRs

Mon, 30 Mar 2015 13:03:48 +0000

The Arduino Library provides functions like shiftOut() and digitalWrite(). These functions are simple and effective, but they are slow. Of course, they’re doing a lot more than just toggling bits. Faster isn’t always necessary and can sometimes lead to more difficult debugging. And as Donald Knuth said,

…premature optimization is the root of all evil.

So what happens, when you do need to optimize? For example, if shiftOut() is too slow for your project, what do you do? In Ralph’s post, Fastest AVR software SPI in the West, he breaks down different SPI code implementations into their assembly code.

Vintage Turntable Repaired with Arduino (via pitface123)

Fri, 27 Mar 2015 13:55:21 +0000

element14 is running a Design Challenge called Enchanted Objects. The idea is to add magic, or modern technology, into older objects, enchanting them. How could you turn an ordinary household object into something extraordinary?

You can see the content intro video here.

With my recent interest in retro-electronics, an entry by Jan Cumps caught my eye. He’s repaired a vintage record player (turntable) using an Arduino and Pulse Width Modulation (PWM) control. For more information on his work, the project page is here. Jan’s YouTube channel is at pitface123.

Sleep Infographic Using Raspberry Pi and Fitbit API

Thu, 26 Mar 2015 14:58:55 +0000

The Fitbit API allows you to get data from a Fitbit and use it in your own applications.

Paul wrote a Python script which runs on his Raspberry Pi which extracts the data. Then we processes the data using Excel. Once doing so, he created the above sleep infographic–his first effort.

The interesting aspect here, to me, is the idea of these wearable devices and their data. It is great we have large-scale data creation, but it is even better have access to the data for processing.

Check-out these seven new features in the Arduino 1.6 release

Wed, 25 Mar 2015 16:15:00 +0000

The (official) Arduino team has finally released the 1.6 version of the Arduino software. After being in the making for over 2 years, this release is an exciting one!

1.6 marks the end of split releases between the traditional 8-bit boards and ARM based boards. There’s some really cool features built-in, so keep reading to see my take on the good, the bad, and the ugly.

Arduino Compiler for LabVIEW

Mon, 23 Mar 2015 14:20:18 +0000

Aledyne-TSXperts, a National Instruments Alliance Partner, has released an Arduino compiler for NI’s LabVIEW. Now it is possible to build a VI and download it into your Arduino.

The price tags from $99 to $499 might seem a bit high to the average hobbyist. However, at least it comes with a 7-day evaluation period. It is also compatible with the Home Edition of LabVIEW.

Video Review of NI's VirtualBench

Fri, 20 Mar 2015 14:30:33 +0000

National Instruments changed the world of instrumentation when it released the VirtualBench. For about $2000 (USD), they give you a bench’s worth of equipment in a box about the size of Horowitz’s The Art of Electronics! In this video review, I take a look at the VirtualBench’s 6 built-in functions.

This is a follow-up to my written review of the Virtual Bench. I use the same mixed signal oscilloscope (MSO) demo board, to point out what I like and don’t like about the VirtualBench.

Five Raspberry Pi Alternatives (via makeuseof)

Mon, 16 Mar 2015 08:05:44 +0000

Not to long ago the only question about embedded boards was: Arduino or Raspberry Pi. Which really breaks the question down to “microcontroller” or “microprocessor.” Once you decide on a microprocessor platform, there are a bunch of Raspberry Pi Alternatives to consider.

Of course, no single board will always be the obvious “best.” Heck I’ve even got a pile of them on my bench that I haven’t messed with yet.

Awesome 3D Board (BRD) Viewer for EAGLE

Thu, 12 Mar 2015 15:05:44 +0000

3D Render of MSO Demo Board

Earlier I posted a PCB Checklist of items to double-check when sending your board out to a fab. The Dangerous Prototypes blog pointed to a 3D EAGLE PCB tool from a Bulgarian-based developer called Cytec that takes an EAGLE BRD file and renders it in 3D for you.

Come See The Baldengineer's Presentation at APEC 2015

Wed, 11 Mar 2015 14:01:44 +0000

Supercapacitors in Transportation Applications at APEC 2015

The Applied Power Electronics Conference 2015 (APEC 2015) celebrates its 25th year in Charlotte, NC. The conference opens on March 15, 2015 and is focused on power electronics. The schedule of technical sessions range from industry experts to students presenting research papers. APEC’s exhibit floor is usually packed with every vendor in the power electronics supply chain. This is one of the largest electrical engineering shows in North America—and I’m excited to announce I will be presenting in one of the industry sessions!

Funny video from Rockwell Automation on their "Encabulator"

Fri, 06 Mar 2015 17:03:23 +0000

In this Rockwell Automation video you’ll learn all about their latest Encabulator technology. The presenter goes through each piece of the system expertly describing both its name and its function. Now, since this video is from 2008, it is a little bit older. And in today’s technological terms, may be difficult to understand.

(BTW, this is what you probably sound like when you try to explain your projects to your friends.)

PCB Checklist - What to check before you submit

Wed, 04 Mar 2015 15:22:50 +0000

Recently I’ve been expanding my retro game collection to include game cartridges imported from Japan. The problem is that I don’t have Japanese game systems (yet). So I’m creating an open source adapter to convert Famicom carts to the NES. Before I submit the PCB to OSH Park, I’m going to run through this PCB Checklist to make sure I don’t forget something silly.

This PCB checklist is something I’ve built over my years of creating boards. If you’ve got tips from your own list, don’t forget to leave a comment letting us know.

Autorouters Suck: Autorouter: 0. Baldengineer: 1

Tue, 03 Mar 2015 15:06:54 +0000

I am not a fan of relying on the Autorouter in EAGLE – or any PCB CAD software for that matter. When laying out a board, I’ll use the autorouter to get an idea if the part placement is going to work or not. In this case, I was reminded how much autorouters suck! Even after running for while, the autorouter could only route up 50% of the nets (signals).

Check out a SDR based on the Teensy

Mon, 02 Mar 2015 15:18:50 +0000

Teensy SDR Panel from Open Emitter

Several months ago I used my first software defined radio (SDR). This was a USB Dongle that did the digitizing and used Gqrx and GNU Radio for the actual decoding. Playing with an SDR is really fun. At the time I thought about using my Pi as the decoder, but found some performance issues. Imagine my surprise when I saw this project.

How 3D Printing Filament is Made

Fri, 27 Feb 2015 15:56:33 +0000

Make joins Joshua Smith at Makergeeks.com to find out how 3D Printing Filament is made. They make their own filament from scratch and not just source it ready-made from China.

More information and pictures are available at http://wp.me/p22K2I-1Xt2.

AddOhms Electronics Tutorials DVD Now Available

Wed, 25 Feb 2015 15:12:56 +0000

When I was in elementary school, I remember Ms. Coker telling us we needed to memorize our multiplication tables because we wouldn’t always have a calculator. Years later in college I was told, “learn to use the library, it’s not like you can carry the internet in your pocket.”

Buy On Tindie

Seems strange that I always carry 3 devices on me that do both.

Today a generation of people are growing up with the mass of all human knowledge available to them from birth. No formal education is necessary. And the only need is a modern device with WiFi.

ECN's 14 Best Engineering Shows on Netflix

Tue, 24 Feb 2015 12:42:32 +0000

Your Netflix might have some hidden gems buried inside of the growing list of streaming TV shows. It is probably well-known that Mythbusters is available on Netflix, but did you know about these 13 other shows? Not only does this list contain shows like Modern Marvels, there are also a couple of stream-able movies like the Andromeda Strain. Which, for me, was the first non-Star Trek or Star Wars Sci-Fi I remember watching. Which is interesting, because it is directed by Robert Wise, the director of the first Star Trek movie.

Awesome Look at Olympic-Class ships (aka Titanic)

Fri, 20 Feb 2015 15:11:22 +0000

The most well-known Olympic-Class ship is the famous Titanic. While known for his maiden voyage’s epic fail, the Olympic-class ships were amazing feats of engineering. Bill Hammock breaks down the engineering and construction of the RMS Olympic, the first of the class.

Hammock is one of the Author’s of Eight Amazing Engineering Stories, which I already reviewed here. He gives his usual excellent treatment on a subject. I included his Podcast/Video series on my 5 Electrical Engineering Podcasts you should subscribe.

5 (Electrical) Engineering Podcasts You Should Subscribe

Wed, 18 Feb 2015 15:25:12 +0000

Podcasts are an amazing way to extend your knowledge in any subject. This (generally) free content is updated often, comes in a variety of formats, and covers nearly every subject.

Your definition of Podcast might vary from mine. So for this list it means: content regularly produced with the intention of informing on a particular subject which is available either as audio, video, and ideally a RSS feed.

Keep reading to see the different electrical engineering podcasts I listen to.

Review of NI's VirtualBench, All-In-One Instrument

Wed, 11 Feb 2015 15:13:40 +0000

The first time I saw the VirtualBench from NI, I was amazed by its shear size—or lack of size. At the time, the unit I had access to an uncalibrated pre-release unit at the Austin TechShop. So I didn’t think it was fair to do a full review. Fast forward to today. Now that I’ve spent a week working with the VirtualBench I have some comments and thoughts. What follows is a review of this “All-In-One Instrument” that runs $1999 USD.

PacMan theme in 10 different styles

Fri, 06 Feb 2015 15:16:31 +0000

In the mood for some retro game music? Check out D Wave’s YouTube Channel for a fresh take on some retro game tunes. The PacMan melody is good. You might also like his take on the SMB Theme.

Help Adafruit test their #RaspberryPi Bootstrap

Mon, 02 Feb 2015 15:22:41 +0000

When you first get started with a Raspberry Pi, there are a number of operating system images already available. The one most people start with is Raspbian, which is based on Debian Linux.

Adafruit created a fork of Raspbian which they called Occidentalis. Their aim, of course, was for hardware hacking with the Pi. Included are some patches that help make accessing the breakout pins easier.

Their latest project is the Adafruit Pi Finder, which makes it easier to configure a Pi over a network. Check out the details on Adafruit’s blog.

Neodymium Magnets - Will It Blend?

Fri, 30 Jan 2015 15:12:48 +0000

In this “Will It Blend?” Tom takes on neodymium magnet balls. This is a fun one to watch because the balls spark up while flying around. Some really good slow motion replay work here.

If you aren’t familiar with “Will It Blend”, it is a video series presented by the blender maker Blendtec. Tom Dickson attempts to bend various items. Not only the star of the clips, Tom is also the Founder of Blendtec. You can find all their videos at willitblend.com.

Capacitor Questions Answered on The Spark Gap Podcast

Thu, 29 Jan 2015 15:01:24 +0000

Karl and Corey run The Spark Gap Podcast which is focused on embedded electronics. On Episode 25 they interview me about Capacitors. We covered all the major types of caps, plus some application bits. Check out their show notes for an impressive array of links on the subject.

Also, my favorite episode of theirs so far is episode 18. The guys talk about different serial protocols like SPI, I2C, CAN, etc. Really good stuff.

iCircuit's circuit simulator goes from iOS to Desktop

Wed, 28 Jan 2015 17:53:48 +0000

When it comes to schematic capture and circuit simulation on a mobile device, iCircuit for iOS got it right from the start. iCloud integration, intuitive touch controls, and fast application performance. Now (or Finally?), my favorite mobile circuit simulator, iCircuit, is available for OS X.

iCircuit is based on the Falstad Circuit Simulator, which sadly, is a Java-based web app. For years I’ve installed the App on my iPhone and iPad almost immediately after turning on iCloud [for Android users, that’s basically the first step of activating an iOS device].

DIY Active Differential Probe Project

Tue, 27 Jan 2015 15:28:50 +0000

Active Probe Setup (via xellers)

Back when I worked for an Oscilloscope company, we were pretty proud of our differential probes. Even the “low-bandwidth” probes were still around 1GHz of bandwidth.

Daniel Kramnik built an active differential probe and looks like he is seeing about 400MHz usable bandwidth. And really, it looks relatively flat. Not bad for a DIY effort. I’m impressed.

Pretty amazing to think about the possibility of building your own (active) scope probes.

HPDisk - GPIB Disk Emulator

Mon, 26 Jan 2015 15:25:46 +0000

Images from http://www.dalton.ax/hpdisk/

Popular on eBay are old test equipment like Spectrum Analyzers, Oscilloscopes, and Multimeters. HPDisk by Gustafsson Anders creates a virtual GPIB interface that stores data to a SD-Card.This is done by emulating a special HP disk drive, that some HP instruments know how to write to when connected. (As Anders points out, this is not emulating a built-in floppy drive.)

Keep reading if you aren’t familiar with GPIB.

Bill Gates talks about the Altair 8800

Fri, 23 Jan 2015 15:49:57 +0000

Go back to 1975. The idea of a computer at home was something that only happened in Science Fiction books. When the Altair 8800 was introduced, not only could you have a computer at home–you could build it yourself!

For some “computer” is a bit liberal. Based on the Intel 8080, the “computer” supported some toggle switches and LEDs on the front panel. As Gates explains in this video, there wasn’t even any kind of interactive terminal.

Is Graphene Unobtanium?

Thu, 22 Jan 2015 15:57:15 +0000

("Graphen" by AlexanderAlUS - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons)

Every day a new application involving the seemingly miraculous material Graphene is announced. For example, being in the capacitor industry, I am asked often if my employer uses it. Before answering the question, I usually have to explain what Graphene is and the challenges in producing it.

The lack of supply and limited (real) commercial applications leads me to think of it as Unobtanium… at least, for the near future.

10 Popular EAGLE Libraries

Thu, 22 Jan 2015 15:34:03 +0000

Having good libraries in EAGLE is critical to making schematic capture and PCB design fast. Dave at element14 put together a top 10 library link, which includes the list below.

Remember, if you’re having trouble Add Parts, you might want to look at this tutorial on enabling EAGLE libraries.

element14’s RIoTBoard
element14’s Raspberry Pi Compute Module Development Kit
element14’s BeagleBone Black
Linear Technology
Molex
Vishay
Microchip
Atmel
Arduino
Texas Instruments

Role of EMI X1, X2, Y1, Y2 Capacitors Ratings

Tue, 20 Jan 2015 15:52:17 +0000

Understanding what X2 or Y1 capacitors actually are and are not is important when designing them into an AC-mains connected power supply. Recently Electronic Products Magazine ran an article I wrote on the proper role of X and Y safety rated EMI Capacitors.

The X2 capacitor rating means different things to different people–except for UL. When I wrote this article to discuss some common misconceptions around what X2 Rated Capacitors are, and how they can be properly used.

Captain Picard on Decoupling Caps

Mon, 19 Jan 2015 14:56:25 +0000

Fun with the meme generating. When it comes to adding decoupling caps, Make It So.

Space Invaders on Gecko EFM32

Fri, 16 Jan 2015 15:05:08 +0000

The Gecko Zero EFM32 Weather Station Evaluation Board from Silicon Labs is intended to show off the low-energy or energy harvesting capabilities of the EFM32 Zero. The ARM-based board has physical and cap sensitive buttons along with the LCD.

It comes pre-loaded with a demo program, which is the classic Space Invaders.

If you’re interested in more about the board, I wrote a road test of Gecko EFM32 on element 14. (Spoilers: I wasn’t impressed. Not a bad board, but rough development environment.)

Clean Ground Planes on DIY Boards

Thu, 15 Jan 2015 15:14:41 +0000

If you’re making your own PCB with the toner transfer method, you might find that getting nice clean ground planes is difficult. John on twitter (@ johngineer) realized a simple, but effective method.

Use a hatch pattern for your planes and then fill in the squares with a Sharpie. Simple, but effective. The paper detaches easier and the etch comes out cleaner.

For help on creating ground planes in EAGLE, check out this video tutorial I put together.

CES 2015 Highlights

Wed, 14 Jan 2015 15:43:26 +0000

This is my first year attending CES. Apparently, nobody told anyone here about the death of the trade show. As an enginerd, here is my perspective. First, if you’ve never been, this show is huge. Huge. You aren’t just walking around 100 or so booths. This thing is spread across 3 different conference centers in downtown Las Vegas.

With over 160,000 attendees, CES was spread across three massive convention halls. Nearly every company offering electronic products were on display. From Televisions to Appliances to Computers to Automotive Electronics to Wearables. Broken down below are highlights and pictures from the show, based on industry or application area.

Eight Amazing Engineering Stories: Using the Elements to Create Extraordinary Technologies

Tue, 13 Jan 2015 15:11:54 +0000

Bill Hammock’s “Engineer Guy” podcast series was one of my first video podcast subscriptions. His explanation videos hit the right balance between “high level’ and “low-level” details in a few short minutes, which was actually an inspiration for the format of AddOhms. With each of his videos, you will learn something and get a few laughs–which is rare for engineering related videos.

His book, with co authors, “Eight Amazing Engineering Stories”, was added to my Kindle App as soon as it became available. The book breaks down everyday objects and technologies down to their science and engineering fundamentals.

Capacitor innovations address emerging opportunities on PSD

Mon, 12 Jan 2015 14:57:28 +0000

Article I wrote on some innovations KEMET has implemented in their capacitors:

" There is no Moore’s Law for passive components like capacitors, but relentless development is delivering the kinds of devices engineers need to deliver cutting-edge new products for modern living. Capacitors have for many years enabled electronic designers to manage energy within circuits and fulfill basic functions like filtering noise or harmonics, correcting power factor, stabilizing feedback circuitry, coupling/decoupling, interfacing between voltage levels, and storing energy. But the demands placed on these components continue to increase, as electronic devices are expected to be smaller, longer lasting, more feature rich and more robust."

Quake on an Oscilloscope

Fri, 09 Jan 2015 21:53:43 +0000

Video is rendered on a PC and provide to the analog scope for X/Y graphing.

Installing Arduino Library from GitHub

Wed, 07 Jan 2015 14:45:58 +0000

What happens when you have a random chip or sensor you want to interface with an Arduino, but don’t know how? You search for a pre-existing library of course. And where are many libraries hosted and available from? A place where eager developers hack together code, post updates, and collaborate with others: Github!

Installing a library

Many Arduino libraries are available from GitHub. It really fosters the spirit of Open Source work. If you come across a library you need on GitHub, getting it into the Arduino IDE is relatively simple. However, if you’re new to GitHub (or the Arduino IDE) you might miss the simple steps.

[TIP] Fixing Garbage Serial / UART Communication

Tue, 06 Jan 2015 15:02:43 +0000

If you’re using serial (or UART) communication between two devices and seeing data corruption, there could be a simple fix. For example you might be trying to communicate between two Arduino boards, using one Arduino Uno as a Serial-to-USB adapter for another board, or have an Arduino connected to a Raspberry PI.

If you’re getting corrupted transmissions that get worse at lower speeds, double-check you have common grounds between the boards. Inductive coupling is probably letting the communication work. Without the common ground though, your transmission is going to be susceptible to all kinds of noise.

Rigol Offers 100MHz and MSO for $1,000 USD

Mon, 05 Jan 2015 17:02:24 +0000

Oscilloscopes are the most critical tool when it comes to debug and analysis of electronic circuits. In recent years, digital oscilloscopes finally surpassed their analog equivalents. (10 years ago I would still make an argument for analog, but not anymore.)

The most innovative change to digital scopes came with “Mixed Signal Scopes.” In addition to the high-resolution analog channels, you get 16+ digital channels time-correlated. Digital channel in this context means only seeing a 0 or 1, kind of like a logic analyzer.

Astronomically Correct Twinkle Twinkle | MinutePhysics

Fri, 02 Jan 2015 14:53:39 +0000

MinutePhysics, one of my favorite YouTube channels, has done a collaboration project to provide an animated short on a scientifically correct version of the Children’s song, “Twinkle Twinkle Little Star.”

They are also offering an eBook at: http://minutephysics.com/twinkle

(Looks like if you pre-order the printed book, you’ll get a free copy of the eBook.)

[App Note] Extending Soldering Iron Tip Life from OKI/Metcal

Thu, 01 Jan 2015 15:20:16 +0000

After mentioning how much I like using a brass sponge when soldering, I came across this App Note from OK International. This is a great note to read through. It discusses what is inside of a soldering iron tip, why they fail, and how to keep them in good shape.

Image from OK International’s Tech Note

The note actually makes me realize two of my own mistakes.

My Top 10 Posts from 2014

Wed, 31 Dec 2014 14:07:30 +0000

From Jan 1 2014 until today, baldengineer.com’s traffic has increased 150%. With so many new readers, I thought about how to make better posts for you. That lead me to look at the top posts in 2014. Below are the most viewed posts from the past year, plus some honorable mentions.

Learnings

You know what is interesting? There is only one post for 2014 and it’s #1 on the list. Guess that one resonated with some people. Also, except for #8, the top posts all relate to Arduino in some way.

Brass Sponge over Wet Sponge

Tue, 30 Dec 2014 15:12:10 +0000

Keep your soldering iron tip from oxidizing.

As it gets dull and gray, it’ll be harder to make good solder joints. My favorite tool to clean a tip is a Brass Sponge. The other option is a damp cellulose sponge, but I’m not a fan of those.

I have just never found a sponge gets the tip as clean as a light dabbing from the brass sponge.

Just be careful not to “scrub” too hard, you don’t want to scratch the tip. When you done soldering, make sure you clean it with the sponge then coat the tip with fresh solder. Leave that solder on the tip until the next time you use it. The layer of solder will prevent oxidation from building up while the iron sits unused.

Signal and Power Integrity - Simplified (2nd Edition)

Mon, 29 Dec 2014 16:25:32 +0000

Let me start by saying, this book is not for new comers, or (ugh) “newbies”, to electronics. This book is intended for those who have a solid understanding of electrical engineering fundamentals, but want to expand to the next level. Bogatin’s amount of detail is on-par with a textbook but writing style is more casual.

Understanding signal integrity use to be “Black Magic.” It is taught in a language which resembles engineering speak, but sounds like randomly assembled terms purposefully meant to confuse people. Personally, I remember hearing “signal integrity engineers talk” and wondered if they were speaking in code.

How does a transistor work by Veritasium

Fri, 26 Dec 2014 16:05:17 +0000

One of the best ways to describe a transistor is as an “electronic switch.” They are solid state devices that make up almost everything in our world. This video by Veritasium, which is a bit older, covers how n and p-type transistors actually work.

This complements the Addohms videos on BJTs and MOSFETs, which are more about how to use them.

Happy Holidays and Merry Christmas

Thu, 25 Dec 2014 11:00:19 +0000

Minecraft animation from PoetPlays.

Happy Holidays Everyone.

An example of when comments would have helped

Tue, 07 Oct 2014 14:00:05 +0000

What was one of the first things you were taught, when learning to program? “Comment Your Code!” And of course, like all programming students, you ignored that advice. Or, if you are like me, you made vague comments as the lines of “variable called var.”

Tonight I opened up some code I haven’t touched in two years. Code that when I wrote it, made perfect sense to me… at the time.

Software Defined Radios are Awesome

Wed, 10 Sep 2014 12:00:27 +0000

Early in my engineering career, I worked for an oscilloscope company in the high performance product line. The last project I worked on was defining the features and requirements of a 33GHz (that’s giga-, not mega-) scope. This experience gave me a strong appreciation for processing digitized signals, especially those in the RF range. So when I picked up my first Software Defined Radio (SDR), you can imagine how much fun it was to use… with the help of some open source hardware.

Open Vapors (Reflow Oven) Controller Update

Tue, 29 Jul 2014 14:00:00 +0000

The Open Vapors project has taken some big steps forward recently. The controller’s enclosure is now a custom box, has a front panel, and the LCD’s menu system is almost done.

Hardware

Some notes on the hardware pieces, pretty much everything has been

IMG_6556

Behind the scenes of AddOhms #11 (MOSFETs)

Thu, 24 Jul 2014 14:00:40 +0000

The 11th AddOhms Video is live and the subject is What is a MOSFET, and how to use them. This turned out to be the longest video I’ve made so far. In fact, I probably should have broken off the power dissipation part, but felt it needed to be addressed. I think many non-engineers look at a MOSFET (or regulator) datasheet and see a huge power value or current rating, but not realize you need a heatsink to achieve them.

Hands On: National Instrument's VirtualBench

Mon, 21 Jul 2014 14:00:27 +0000

Modern smartphones have eliminated the need for a number of devices. Often I use my smartphone as a scanner (CamScanner), car GPS, voice recorder, security token, pedometer, light controller, and oh yeah, a phone. My electronics bench is currently home to a Bench Power Supply, an Oscilloscope, and a Function Generator. While good instruments, they should worried because they’re going to get replaced with one device: National Instrument’s VirtualBench.

This relatively small box (10in x 7.5in x 3xin) gives you a rack of equipment in a compact package. Plus, the performance of the instruments is seemingly good for the approx $2000 (USD) price point.

First Impressions of Electron, a new Node.js IDE for Arduino

Mon, 07 Jul 2014 14:00:53 +0000

The Arduino IDE is great in that with a single download on any PC platform, new users can start writing code and see immediate results. The same simplicity though, limits some of the more “advanced” features found in modern editors. Also one of the IDE’s greatest strengths is cross-platform through Java. This is also one of its weaknesses. Java is outdated and it’s time to move on.

There’s a slew of other Arduino development environments out there, but most of them are limited to 1 or 2 platforms. Electron is a novel idea because it is based on Node.js, meaning it runs in Google’s Chrome.

6 Simple Mistakes Electronics Beginners Make

Mon, 30 Jun 2014 14:00:47 +0000

Sometimes the hardest lessons are the ones you have to learn multiple times. When getting started with Electronics circuits, there’s a handful of things that can ruin a day (or experiment.) Here are 6 mistakes I made when I got started, and mistakes I see in the beginner classes I teach. In fairness #6 isn’t one I did starting out, because Fritzing wasn’t around. However, it took me a while to learn the value of providing a schematic, even a simple sketched out block diagram.

Please take my 2014 Reader Survey

Mon, 23 Jun 2014 15:00:49 +0000

I want to make my blog a better for your interests. That means, I need to know about YOU!

Would you please take a few minutes and answer a few questions? By doing so, you’ll actually be helping yourself. How? Because I’ll be able to make better content and more posts that are relevant to you.

Survey link: https://www.surveymonkey.com/s/VLHQSZJ

To keep all of the responses anonymous, I am using SurveyMonkey. The reader survey is only 2 pages and 10 questions, so it should takes you less than 5 minutes.

Are you an engineer?

Wed, 11 Jun 2014 20:48:26 +0000

One of the recent changes in pop-culture is that “nerds are cool.” Most people who claim to be a nerd like to wear 1950s (non-corrective) glasses and download Apps on their iPhone. Some go farther and say they’re engineers. Here’s how you can sort out the posers.

The original author for this test is unknown. A quick Google search comes up with a number of duplicates, but no one claiming to be the author. So, republished with my own comments (and slight edits) is, the “Engineer Identification Test.”

"Post your code" to the style of "Let it Be"

Mon, 09 Jun 2014 15:00:06 +0000

A friendly reminder video to everyone asking for help in a programming forum.

Lately I’ve been looking for ways to expand on the content in the AddOhms YouTube channel. One of the thoughts I had were taking some of the hard engineering lessons and turning them into a “Public Service Announcement”. You know, like those short films that would run on TV after school or NBC’s famous " The More You Know." Not something so dry, but something at least a little entertaining.

Well formatted Arduino code in one click

Fri, 16 May 2014 15:00:06 +0000

Warning, the title of this post is a little bit misleading. It isn’t just one-click to get cleanly formatted code, it’s actually two.

There are two things seasoned programmers will tell new programmers, that they don’t understand (at first):

Always comment your code
Properly indent code

The problem? As a new programmer, you might not know how to do #2 until you get some experience.

How indenting helps

The reason you indent code is to make it easier for a reader to understand the code’s flow. A compiler (well except in Python) doesn’t care if two lines line up or not. T he recent issues around Apple’s “goto fail;” are a great example of how indentation is meaningless to a C compiler.

Review: The Art of Electronics [Book]

Mon, 12 May 2014 15:00:34 +0000

Title: The Art of Electronics by Paul Horowitz and Winfield Hill.

Most electronics books are written by engineers, for engineers. It is difficult to find an extremely comprehensive book which covers most Electronics subjects that is written in plain english.

This is that book.

Book Structure

The book’s chapters are broken out into logical sub-groups like “Foundations”, “Digital Electronics”, and “Microprocessors.” There are 15 chapters and a number of appendixes with useful information. Within each chapter information is broken out into a number of headings. At the end of most chapters are “Circuit Ideas”, “Bad Circuit [examples]”, and Exercises.

AddOhms #10: BJTs as Transistors

Fri, 09 May 2014 11:30:15 +0000

Every Addohms project follows the same pattern. About 80% of my original idea makes it into the video while the remaining 20% I make up on the fly. Of course, when I do that, I spend 80% of my time on that 20%. AddOhms #10 on BJTs is no different.

The 4 best transistors to keep in your parts kit

Mon, 21 Apr 2014 15:00:38 +0000

When your project needs a transistor, there are tons of choices. Which makes answering the question “Which transistor should I use or buy?” a daunting task. Fear not, before wading through spec sheet after spec sheet, consider one of these four general purpose transistors. Every electronics enginerd’s toolbox should have a few of each.

Transistors are one of the most versatile discrete components in electronics. In digital circuits, they switch on and off while in analog circuits they are used to amplify signals. For most projects, they are used to turn on a load that would kill the I/O pin of a microcontroller or microprocessor. For most circuits either a BJT or MOSFET can be used, depending on the load current you need to switch.

Let's connect on element14

Fri, 11 Apr 2014 11:00:36 +0000

What does Silicon have to do with Social Media? Silicon’s Atomic Number is 14. Wait what? Oh… element14 is, basically, a social media site for electrical engineers, embedded designers, makers, and hobbyist. Forums, blogs, videos, and all kinds of resources from “celebrities” around the EE world.

It’s one of the most active communities and, in my opinion, one of the cleanest layouts. Over the past few months, I’ve been becoming more active there. If you’re there, check out my activity feed and add me as a contact! It’s a great way to stay in touch.

Teach your Arduino to listen with µSpeech

Tue, 08 Apr 2014 15:00:11 +0000

When most people say “Arduino” they mean an ATmega328 based board like the Uno. This means a simple 8-bit microcontroller with only 2K of RAM. That’s 2,048 bytes of memory to work with. So when someone asked me if the Arduino could do speech recognition, to be honest, I laughed. Then my jaw dropped when I saw µSpeech. A speech recognition library for the Arduino Uno’s ATmega328.

The algorithm used is sophisticated and results will vary based on the types of words used as well as the hardware. It uses only 160 bytes of RAM.

Arduino: Assignments != Comparisons

Thu, 03 Apr 2014 15:00:59 +0000

There is one mistake that all C programmers make, regardless of experience. You’ll do it often when you get started, but never completely stop. The mistake? Confusing the “assignment” operator with the “comparison” operator. Take a look at this line of code:

if (something = 0) {

Notice the problem? If not, then you might fall into this common trap. The most annoying part? A C-Compiler won’t give an error. That code is legal C. Legal code doesn’t mean you’ll get the results you expect. In fact, this is probably not even close to what you wanted. This simple mistake and why it “works” is explained below.

April Fools' 2014 Jokes for Enginerds

Tue, 01 Apr 2014 16:35:12 +0000

Each year it is fun to see who gets “got”. With Twitter fever getter hotter each day, people can’t help but spread juicy news details. Here’s a running list of the April Fool’s Gags I ran across in 2014 (updated links at top of list)

OSHPark is going to switch to Green PCBs
- https://twitter.com/oshpark/status/451084822317113344
Instructables going to sell all their Instrustables in a single book
- http://www.instructables.com/community/Coming-Soon-EVERY-Instructable-one-massive-book/
Waze Introduces WazeDates (Video)
- https://www.youtube.com/watch?v=XfCS9CN91RU
Make Magazine’s list of reader’s pranks
- http://makezine.com/2014/04/01/prank-call-and-answer/
Sphero Introduces “Selfibot” (Video)
- https://www.youtube.com/watch?v=ZaR4X2iJo6M
Raspberry Pi Shows off new retro design
- Click here for a Cached Screenshot of the Pi Joke Page
Kickstarter is changing it’s name (less vowels)
- https://www.kickstarter.com/blog/the-new-kickstartr
Single Person Tool Shop, Boldport, Acquired by Apple
- http://boldport.blogspot.com/2014/04/apple-acquires-boldport.html
Octopart Now supporting Snapchat
- http://octopart.com/blog/archives/2014/4/now-send-rfqs-using-snapchat%2521
iFixIt Acquired by Apple
- http://www.ifixit.com/apple_press_release
- Complete with red herring as shown in their new Smartphone Replaceability Indexes
Think Geek’s Flux Capacitor Charger
- Seriously hope this one becomes real: http://www.thinkgeek.com/product/1ba1/
Sparkfun ran a sporting contest
- https://www.sparkfun.com/news/1443
Bored Elon Musk’s Tweet on if you should do an April Fool’s Joke
- https://twitter.com/BoredElonMusk/status/450765914875518976

I can’t help but think that Apple is going to not like repeatedly being used in these yearly jokes. What jokes have I missed or what were your favorites? Leave them in the comments.

AddOhms: Questions and Answers #1

Fri, 14 Mar 2014 02:00:31 +0000

In the past couple of months, AddOhms has caught a little bit of a following. Nearly every day I have new questions coming my way. I decided to it was time to address a couple of really good questions in a video response. Ironically, in the video I mentioned giving “behind the scenes” info with each video. However, for this one, I don’t really have any. I can say that the next video is going to be on transistors…

9V Batteries Suck -- And why you shouldn't use them.

Fri, 14 Feb 2014 12:00:37 +0000

Smoke detectors beep when their backup battery dies, which always seems to occur in the middle of the night (at least for me.) These backup batteries are usually a small rectangular 9V. They have become popular choices for electronics projects. If you need your Arduino project to last longer than a day, this isn’t the battery you want to use. Here’s why.

What is a 9V Battery

The 9v battery comes in a standard package about 25mm wide, 16mm tall, and 47mm long. On top there are standard snap-style connectors. The design of these connectors prevents you from attaching the battery backwards.

3 Options for Keeping Track of your Parts

Wed, 12 Feb 2014 12:00:45 +0000

As your electronics hobby grows, so does your parts collection. Eventually the growing number of Mouser boxes with crudely written labels just won’t cut it. Also, you’re tired of re-ordering parts you had but forgot about. Here’s a couple of ways to keep track of your parts like a pro.

Text File (aka Evernote)

The most basic option is a text list stored as a text file or in your favorite note taking app. Eventually I moved my text file over to Evernote. It had the benefit of being mobile so I could update it as I found those parts hiding in plain site. The limitation though is that it’s just a flat text file. No sorting, limited searching, and nothing to prevent duplicate entries.

AddOhms #8: LEDs and Current Limiting Resistors

Mon, 10 Feb 2014 12:00:49 +0000

The idea for AddOhms #8 has been around for quite some time. I’m always trying to find ways to explain why current limiting resistors are necessary. So while working in the shop one day, I decided to play with some LEDs and a bench-power supply. Then I decided to record what happens.

Stuff from Tokyo

Fri, 24 Jan 2014 12:00:50 +0000

It’s been a little quiet on the blog because I spent the last three weeks in Asia. There’s some electronics enginerd stuff coming next week. Until then, I hope you’ll excuse this rare off-topic post. While in Tokyo I saw a number of awesome things and thought I’d share 2 of them: ASIMO at the Miraikan Museum and a dinner show at the Robot Restaurant. Click Read More to check out some pictures and videos.

EAGLE Trivia Challenge: Why the ratnest?

Sun, 05 Jan 2014 12:00:40 +0000

Your challenge, if you chose to accept it, is to determine why EAGLE is showing a ratsnet connection on the far left of the PCB layout. The pads shown with the yellow unrouted line are both GND. They are both surrounded by a ground plane, which is also connected to GND.

Hint: it isn’t a bug and it is something many people might ignore by mistake.

Can’t figure it out? Or you want to see if you got it? Use a ROT-13 converter for the answer:

EAGLE: Creating a Custom Library for your own components

Fri, 03 Jan 2014 12:00:38 +0000

When you start creating your own parts in EAGLE, you’re going to want to store them somewhere. Here’s how to setup EAGLE to use custom directories and how to create your own Library, which gets stored in the custom directory. There are a number of steps involved, but once setup custom libraries give you a place to store components you create as well as the ability to copy other parts into your library.

When do you use the Arduino's Serial.flush()?

Thu, 02 Jan 2014 12:00:47 +0000

In the Arduino library, the Serial object has a method called “flush().” Often users go throwing it into programs without fully understanding what it does. It doesn’t help that it’s functionality changed when version 1.0 of the Arduino IDE was released.

Does Serial.flush() affect the Transmit Buffer or the Receive Buffer and when do you need to use it?

What does Serial.flush() do?

From the Arduino reference for Serial.flush (found on this page):

5 Myths Everyone Believes about Arduino (that aren't true)

Wed, 01 Jan 2014 12:00:59 +0000

Having spent the past 6 years writing code for the Arduino platform, I’ve noticed a trend in myths from both newcomers and veteran users. Here are the Top 5 Myths I see come up on forums, in classes, and on IRC.

1. The Arduino uses its own Language

This myth isn’t helped by the Arduino.cc home page used to say

“T he microcontroller on the board is programmed using the Arduino programming language.”

Unlike Speed Limits, Ohm's Law isn't a Suggestion

Tue, 31 Dec 2013 12:00:51 +0000

Getting started with electronics always involves a discussion of Ohm’s Law. What is this mysterious sounding law and how can you use it when building electronic projects? One the main uses for Ohm’s Law in your projects is to calculate the resistor value needed for a LED. This article takes a look at what Ohm’s Law is and how to use it with LEDs.

Overview

Ohm’s Law is really a mathematical rule based on two points. In electronics those two points have a voltage across them (aka potential difference). The amount of current that flows from one point to the other, is going to depend on the resistance between those points. So Ohm’s law says that the Resistance of a device is equal to the Voltage Across it divided by the Current that Flows through it. The formula looks like this:

Electronics: Introduction to Breadboards

Wed, 18 Dec 2013 23:32:05 +0000

Soldering every circuit you build probably isn’t practical. At some point you are probably going to want to use some type of temporary method to connect different components together. One of the popular methods is using a breadboard. This simple (and cool) looking device only needs a few instructions before you can begin

Layout of a Breadboard

There are various colors, shapes, and sizes that breadboards come in. However, they all generally look about the same and have the same basic functionality. The board shown in Picture 1 is a pretty common “medium” sized breadboard.

AddOhms #7 - Comparing Arduino and Raspberry Pi

Mon, 16 Dec 2013 12:00:59 +0000

The seventh AddOhms TutorialCast has gone “live”. (Gone “uploaded” sounds wrong.) Being able to understand difference between an Arduino and a Pi is a critical point for many new electronics hobbyist. The boards seem so similar, but they are so different. AddOhms #7: Comparing the Arduino and Raspberry Pi

Full Episode Notes are available on the Episode’s homepage.

Arduino: De-Bounce a Button with micros() or millis()

Fri, 13 Dec 2013 12:25:45 +0000

The Arduino is fast, humans are slow. When you push down a button, what seems like a single change to slow humans is really multiple presses to an Arduino. This is known as “bouncing.” Figure 1 is an oscilloscope screenshot showing what could happen when a button is pressed.

Figure 1 - All the bouncing!

The top trace shows the high-low-high transition of the button press. But notice all of the activity at the start of the high-to-low transition. The bottom trace is a “zoomed-in” view of that area. The button is actually transitioning multiple times before staying low. Internally the contacts are “bouncing.” This could result in false reads. In software, we can ignore these bounces by waiting some period of time after the first transition.

Arduino: Chasing LEDs with millis()

Thu, 12 Dec 2013 12:00:34 +0000

A popular LED project is the “Larson Scanner.” This scanner emulates the effect seen on KIT from Knight Rider and the Cylons in Battlestar Galactica. The code is usually written using “delay()” which means you can’t combine it with anything else. The following code could be put into a function, called periodically and allow your code to scan while doing other things.

One thing to note, a proper Larson Scanner has some persistence to the next and previous LEDs, this code does not. Maybe that would be a good exercise for the reader?

Arduino: Timing Code with Millis() as a Stopwatch

Wed, 11 Dec 2013 12:25:22 +0000

Since most Arduino boards do not have debug capability, this limits the programmer to using Serial.prints. A useful piece of information might be knowing how long certain parts of code are running. Here’s a simple example that demonstrations:

How to properly use Serial.flush() (hint: it’s for TRANSMIT, not RECEIVE!)
How long Serial.print()s can “tie up” the Arduino.

At 9600 baud, you’ll see that the Arduino is only busy for about 20 milliseconds in the first chunk of code, but busy for 93 milliseconds in the next. That’s because the Arduino (since 1.0) started using a transmit-buffer. Did you know your code doesn’t wait for a Serial.print to finish?

Arduino: Independent On-Off Times with Millis()

Tue, 10 Dec 2013 12:25:29 +0000

When using delay() to flash a LED there is a time for the LED to be on and then off. This makes it easy to have independent control of the “on” and “off” times. The standard blink without delay example doesn’t give you this flexibility.

millis-cookbook-two-duty-cycles

This example code gives you complete independent control of how long a LED (or any OUTPUT pin) stays “ON” or “OFF”. This also demonstrates a very simple two-state state machine.

Arduino Millis() Examples

Mon, 09 Dec 2013 23:00:51 +0000

You’ve recently learned about millis() and can’t way to delete all of your references to delay(). The problem is that you don’t know quite how to convert your code into millis()-compatible code. Here is a (running) list of millis() examples I’ve put together to help.

Baldengineer’s Arduino millis() Examples

Arduino Multitasking - Step by step examples of how to convert delay() code into millis() based code, to simulate multitasking.
Police Lights - Flash two LEDs like strobing police lights
Control ON and OFF time for a flashing LED. - More control than “blink without delay”
Stopwatch Example - Calculate how much time code takes to execute
Chasing LEDs - Larson-scanner style chasing pattern
De-bounch a button (or switch) - No need for de-bouncing capacitor
Delayed events after a button push - Timed events (button push is just example.)
analogWrite() PWM Fading - No delay() and a simple function to keep a LED fading with PWM
Detect Short and Long Button Press - Give one button multiple functions

You might also want to check out my “Blink Without Delay - Line by Line Tutorial.” It is a much more in-depth explanation than the comments provided with the Arduino IDE example.

A week of Arduino Millis()

Mon, 09 Dec 2013 13:25:24 +0000

By far one of the most powerful functions of the Arduino library is the millis() counter. It is also one of the most misunderstood functions. Mastering millis() can unlock incredible amounts of potential with an Arduino. That’s why I’m spending an entire week on millis().

Each day this week I’m posting a new example of how to use millis() in your code. Each will be cataloged on this newly created Arduino Millis() Cookbook Page. If you have ideas for other examples, leave comments below.

EAGLE: Clean up the parts list by disabling libraries

Wed, 27 Nov 2013 12:25:08 +0000

Does it take a few seconds every time you click the “ADD PART” button on EAGLE? Tired of scrolling through an enormous list of parts just to find a capacitor? Here’s how you can reduce the parts listing without deleting a single library.

The Control Panel

In addition to the usual Schematic and Board windows inside of the EAGLE user interface, there is also a “Control Panel” window. This control panel is typically the first dialog you see when you launch EAGLE. Depending on how your directories are set up, your Control Panel may look like mine when everything except “Libraries” is collapsed.

The sounds of dialup on a Spectrogram

Tue, 26 Nov 2013 12:25:17 +0000

This beautiful Spectrogram video is instant nostalgia for any of us who used BBSes back in the 80s and 90s. The video comes from Scott H on Youtube.

Several of the videos I have made incorporate the initial connection sound (until the echo suppression is disabled.)

The hidden Arduino Macro F() fixes random lock ups

Wed, 20 Nov 2013 12:25:33 +0000

It’s 3am but you are not going to bed until you squash this last bug. You sprinkle Serial.print() statements everywhere you can think of, and then that’s when all hell breaks loose: Your code randomly locks up, the LEDs go crazy, and you’ve had it. What’s going on? You’ve run out of RAM!

All of those Serial.print() statements are composed of c-style strings. Which are “constant character arrays.” In order for those arrays to work properly, they get loaded into the ATmega’s RAM before your code starts running. Which can be a problem because 2,048 bytes of RAM doesn’t allow for much.

Three Alternatives to Arduino's Serial Monitor

Tue, 19 Nov 2013 11:39:29 +0000

The Arduino IDE includes a “Serial Monitor” which is decent for basic serial communication. However, when you need real time serial interaction or data logging capabilities, that’s when one of these serial monitor alternatives can come in handy.

putty [Windows]

Download: PuTTY. License: MIT.

Hands-down one of my favorite terminal applications for Windows is PuTTY from Simon Tatham. In addition to being a great serial terminal it can also handle telnet, ssh, and a host of other things (no pun intended). The source is available and looks like it runs on UNIX platforms, but I have never tried. If you’re using Windows, this is probably your best go-to terminal application. Every Windows machine I use gets PuTTY in the Start Menu shortcuts.

EAGLE: Using the Add Part's Search

Mon, 18 Nov 2013 06:41:10 +0000

If you are anything like me, your copy of EAGLE has an extensive list of libraries. Most of them probably came with the installer, some which you have added. This, of course, leads to the problem of finding the parts you need when drawing your schematic. Here’s how to use the “Search” box to help.

The Problem

Here’s what my Add Part screen currently looks like:

It’s a mess right? All those libraries, how can I find a single part? That’s where the Search box really play a critical role.

Using Adobe Illustrator to Create A Sine Wave

Fri, 15 Nov 2013 11:33:52 +0000

When working on the AddOhms video on the difference between AC and DC, I needed a vector diagram with a sine wave. Using Adobe Illustrator, I tried with a Bézier tool, but it didn’t look quite right. Here’s two methods I found to create a better line sine.

The Quick (but not Accurate)

This method will give you something that looks sort of like a sine wave, but isn’t actually a sine wave. So if you just need a quick wavy line, this is pretty simple.

Const vs #define - When do you use them and why?

Thu, 14 Nov 2013 11:13:40 +0000

Arduino boards have microcontrollers with notoriously small amounts of RAM. The Uno only has 2,048 bytes of static RAM available for your program to store variables. So when you need to keep non-changing variables out of RAM which is best to use const or #define?

What is #define

#define is often misunderstood because it isn’t a programming statement. Instead, it sets up a macro which causes a text replace to occur before code is compiled. For example in this code:

AddOhms #6: Analog and Digital

Wed, 13 Nov 2013 12:52:09 +0000

It isn’t always clear what is meant by calling a device or a signal “analog” and “digital”. This AddOhms tutorial explains the difference between analog and digital by using an analogy to clocks. Old-school clocks with hands are a great example of “analog” while alarm clocks with digits as their display are an excellent example of “digital”.

Introduction to Polymer Capacitors

Tue, 12 Nov 2013 13:15:37 +0000

November 2013’s issue of Electronic Products features an article on the cover titled “Introduction to Polymer Capacitors.” The author is, well, me. This article explains the differences between traditional MnO2-Tantalum and Polymer-Tantalum capacitors. Previously I explained these differences in the post on the fire hazard the Arduino GSM shield poses (due to improper derating).

You can find the Electronic Products article wherever magazines are sold or here: Introduction to Polymer Capacitors. Check below for links to high-resolution pictures.

Arduino pinMode(): When to use and why

Mon, 11 Nov 2013 11:57:39 +0000

All Arduino boards have GPIO pins with digital and analog capabilities. The Arduino pinMode() function determines how the pins will operate. A surprise might be that in some cases it is not necessary to use it. And when you do, pinMode() may not always work the way you expect. This post outlines how the Arduino pinMode() function works and when you should (or not should) use it.

pinMode(13, OUTPUT);

Arduino pinMode() scope

This post focuses on the 8-bit AVR Arduino boards such as the Uno, Mega, and Leonardo. The processors on these boards are the ATmega328, ATmega2560, and ATmega32u4, in that order. For the most part, this information does apply to non-AVR and 32-bit Arduino variants. When in doubt, double check with the Arduino Reference pages for details to specific platforms.

Understand the difference between DC and AC

Wed, 25 Sep 2013 14:10:17 +0000

The fifth episode of AddOhms tackled the difference between AC and DC. One of the things I wanted to stress in this tutorial is that even though the acronyms stand for “current”, they get used to describe voltages as well. Which, after a video on the difference between voltage and current, seemed like something that needed to be stated.

Learn how to use a Mixed Signal Oscilloscope

Tue, 24 Sep 2013 02:15:33 +0000

When I teach the Electronics Measurements class at the TechShop in Austin, I take a lot of pride in showing off the Mixed-Signal Oscilloscope. We have a Rigol DS1102D as well as a standard DSO. To help illustrate the power of the combined digital and analog channels, I created a Mixed Signal Oscilloscope Demo Board, based on a counter, that has an issue that could be turned on or off. This board is also my first time making use of OSH Park’s PCB service.

Ouch. The Arduino GSM shield has a pretty serious design flaw, with its capacitors.

Sat, 14 Sep 2013 02:44:39 +0000

Tantalum is a really misunderstood capacitor. Well, all capacitors are misunderstood, but that’s a subject for another post. I ran across this post on the Arduino forums on the Arduino GSM shield. In the post, ddewaele, reports that the shield blew up, catching fire. At first some might think it was due to abuse by the user. While it is possible that reversing the polarity or applying over-voltage could cause a catastrophic failure, it is also possible that the user doing nothing wrong could result in the same failure mode!

Minor updates to the Open Source Reflow Oven Project

Tue, 03 Sep 2013 00:06:06 +0000

The next stage of the reflow oven project is moving to a custom PCB for the controller electronics. Overall the board is based on the ATmega32u4 with a DS3231 RTC. The LCD module is intended to be driven by one of Adafruit’s Serial backpacks. There is an area of LED indicators (something I learned from a previous project) and some extra VCC/GND pins sprinkled about.

Screenshot of the controller board laid-out.

MSO Demo Board

Mon, 26 Aug 2013 00:10:15 +0000

Last Update: 09/24/2013

Status: Done

Github: https://github.com/baldengineer/Mixed-Signal-Oscilloscope-Demo-Board

Abstract

As a member of the TechShop in Austin, TX I teach a class on Electronics Measurements. The class includes a variety of test equipment like power supplies, DMMs, and Rigol oscilloscopes. One of the oscilloscopes is a Rigol DS1052D which is a “Mixed Signal Oscilloscope.” In addition to the two 100MHz analog channels, the scope also include 16 digital channel channels. It is a logic analyzer and oscilloscope in one!

EAGLE: Introduction Class Resources

Sun, 18 Aug 2013 02:03:25 +0000

The following resources compliment my EAGLE Introduction Classes and eBook. Files mentioned in those resources will be provided here, although, the original creators may have newer versions available.

EAGLE Tutorials

These are EAGLE tutorials I have created. There is a mix of written and video content.

Groudplanes (video): /blog/2012/07/25/eagle-ground-plane-polygon-fills/
Creating Split Names: /blog/2012/12/26/creating-split-net-names-for-eagle/
Copy and Paste (video): /blog/2013/03/01/eagle-tutorial-copy-and-paste/

More EAGLE Stuff

The following lists are resources which I have found on the web, which compliment my work in EAGLE. Often questions like “what is the best PCB place” or “who makes the best PCBs” gets asked. Best is subjective. These tools and manufacturers are ones that work best for me.

A new series on AddOhms, Electronics basics, starting with: Voltage, Current, and Power Explained.

Sat, 13 Jul 2013 00:53:31 +0000

Starting with this new AddOhms TutorialCast series, we are taking a look at Electronics Basics. The first topic is on the differences between Voltage, Current, and Power. The twist on this explanation is that we are not using the usual “electricity is like water” analogy engineers seem to love. Instead, we just use plain language to explain the difference between these concepts.

From a production point of view, I am really having fun with these videos. Using some green card stock, imagination, and easy to use tools, I am able to achieve some pretty cool effects. Well, I think they are pretty cool. Check out this screen shot from Final Cut Pro X.

EDN: What size and type of output wires should I use?

Tue, 11 Jun 2013 16:51:19 +0000

In an ideal world, wires would be ideal. They’d have no resistance, and therefore, no voltage drop. As we all know, our world is far from ideal which means so are our wires. While copper is an excellent conductor, it does have some resistance associated with it.

This means when designing DC circuits, very common in the hobby world, you may need to take into account the size of the wire you’re using.

Introducing the AddOhms TutorialCast

Sun, 05 May 2013 20:53:51 +0000

Over the past several months I have been kicking around a new way to teach non-engineers about electronics. My idea is to use simple language to explain complex engineering subjects. Each video will be in the range of 3-5 minutes. While putting together the first couple of topics I started to realize I wanted this to be something to stand on its own.

So I have created a separate webpage, twitter account, and YouTube Channel for this TutorialCast called “AddOhms.”

Prototyping quadrotor arm mounts with MakerBot Replicator 2

Sat, 27 Apr 2013 22:45:27 +0000

While practicing the Quadrotor’s motor mounts on a Shopbot gave me experience in how to register two sides for milling, I didn’t want to invest the time required for the arm mounts. So I decided to make use of the MakerBot Replicator 2 to print physical samples in PLA. Time per piece went from about an hour to about 15 minutes.

This is the first time I used the Makerware software, which looks to be a much prettier version of ReplicatorG. The workflow for using the software is a little bit more straight forward than ReplicatorG. For example, a single “Make” button generates the Gcode and Scd Files

HackEDA: Collecting and Sharing reusable pieces of electronic designs

Thu, 25 Apr 2013 09:14:56 +0000

One of the most commonly used phrases when writing software is “reusable code.” From the Wikipedia article on “Code Reuse”. Reusable code is:

the use of existing software, or software knowledge, to build new software.

Software coders have been sharing and re-using code since they first start programming. So why can’t this same idea be applied to hardware design? Doesn’t it seem silly to redraw the ATmega328 for an Arduino based project or even the really simple linear regulator circuit? Well, it can thanks to HackEDA you can start using reusable code to save time (and from creating mistakes).

100kGarages: CNC Router Bits Demystified

Tue, 23 Apr 2013 09:28:14 +0000

Early on in planning the design for the Quadrotor, we knew that eventually some of the metal parts would need to be milled. Having very little milling experience, other than a couple of basic-use classes at TechShop, I had no milling experience. When it came time to start buying router bits for the ShopBot and Tormach CNC routers, I didn’t know what kind of bits were necessary.

OSX: Fixing the "Green Screen" issue when capturing your desktop (with Quicktime or other)

Mon, 22 Apr 2013 20:46:23 +0000

After spending too much time waiting for effects to render on my new AddOhms Tutorialcast, I decided it was time to upgrade computers. When I went to capture a quick EAGLE video on my new MacBook Pro with Retina screen, I realized a problem with the Mac’s auto graphics chip switch. Quicktime recorded only a green Screen.

Architecture

The MacBook Pro Retina has two graphics processors. One is built-in to the Intel CPU while the other is an external chip with significantly more processing power. When on battery, I usually let the computer decide which need it needs to (hopefully) maximize battery life.

Custom Made Quadrotor - Overview

Sun, 21 Apr 2013 18:06:55 +0000

Status: Active, In Progress (Updated: 4/18/2013)

Abstract

Pictures: http://www.flickr.com/photos/cmiyc/sets/72157633185131473/with/8653034709/

This Quadrotor project is a collaborative effort between Mike Kurdziel and I. The unique twist on this collaboration is that he is located in Menlo Park, CA and I am in Austin, TX. We’re collaborating remotely while doing most of work on the TechShop locations in each of our towns.

Our Quadrotor is desgined from scratch. All major components have been adapted from other sources but, otherwise, designed by us for this project. We have no flight experience and neither of us has ever attempted a project on this scale before.

Building a custom Quadcopter from scratch

Sun, 21 Apr 2013 17:36:51 +0000

A couple of years ago I started looking at what it would take to make a quadcopter. At the time, I only had the limited tools at the Austin hackerspace available to me (which I don’t think even has a space anymore). So I shelved the idea since I didn’t see a time effective way to make any of the components. Fast forward to a few months ago when I joined the TechShop in Austin. Now I have no excuses to not make a custom Quadrotor.

Guide for finding the right fastener for your project from BoltDepot

Fri, 12 Apr 2013 20:24:58 +0000

BoltDepot.com sells a huge variety of fasteners which can be useful in hardware projects. One of the resources they provide is a Illustrated Guide to Fasteners. This is a great way to find the name of the screw or bolt you need to hold your hardware projects together. A printed copy is going into my toolbox.

PDF available from BoltDepot.com

EAGLE Tutorial: Copy and Paste

Fri, 01 Mar 2013 23:34:30 +0000

The concept of “cut copy and paste” goes back to a time when people hand wrote all of their documents. The modern concept was introduced to the computing world by Xerox PARC and Apple’s Lisa / Macintosh Now nearly every piece of software offers some level of copying and pasting, including CadSoft’s EAGLE Schematic and PCB software.

Unlike a text editor or illustration program, EAGLE implements copy and paste is literally a little bit backwards. This video explains how to copy single elements in an EAGLE schematic as well as copy entire groups of elements.

Simple Effect using Chromokey and Final Cut Pro X

Fri, 08 Feb 2013 14:30:58 +0000

Editing video has been something I enjoyed doing since High School. There I used my first tape-based NLE video system to make a Jeopardy episode where I played both a contestant and the host. In the skit I got into an argument with myself. Of course that was long before tools like Final Cut, After Effects, or even digital video cameras existed. Now anyone can do cheap effects for fun.

Sawtooth waveform with the Arduino Due's Built-In DAC

Fri, 08 Feb 2013 00:36:18 +0000

Users of the ATmega328 based Arduino boards will recognize that the analogWrite() function doesn’t actually do anything analog. It just sets the duty cycle of a pulse width modulated (PWM) signal. The (new) Arduino Due board, which I have had limited time to play with, actually sports two Analog DAC channels. Using a very simple for() loop, it is possible to generate a sawtooth waveform using these channels.

Math: Animated Factorization Diagram

Wed, 09 Jan 2013 05:26:23 +0000

The web site Data Pointed is run by Stephen Von Worley who is an artist and scientist specializing in data visualization research. He has created a Factor Conga which he describes as

a promenade of primes, composites, and their constituents, arranged with an aesthetically-tuned variation of Yorgey’s rules, one per second.

Check out the Animated Factorized Visualization, which appears to be all done with javascript.

The world's thinnest watch, the CST-01

Wed, 09 Jan 2013 02:23:15 +0000

There’s a Kickstarter project that Andrew Plumb (@clothbot) backed and caught my attention. It is a wrist-band watched based on an e-ink display. The battery cell looks like it can provide about a month worth of charge. A very unique looking watch and for an (apparently) limited time, there is a $100 reward level. As Andrew said, it might be worth it to just take the watch apart!

Revision 2 of the open source reflow solder oven is done!

Wed, 09 Jan 2013 01:22:48 +0000

One of the projects I really wanted to get back to when I joined the Austin TechShop was my Reflow Oven based on a Toaster Oven. The first prototype I made was a mess of AC wiring boxes with an Arduino sitting on the side. While the oven did work, it was far from pretty. Making use of the laser cutter, large workspaces, and friendly members at TS Austin, I was finally able to put together my 2nd prototype.

Laser Cutting Christmas

Tue, 01 Jan 2013 00:34:22 +0000

For Christmas this year, I decided to do something different for my immediate family. Instead of trading gift cards like we usually do, I decided to put to use the Laser Cutter at my Local TechShop. When done, I decided to use iMovie on my iPhone to make a mini trailer…

Creating split net names for EAGLE

Wed, 26 Dec 2012 21:27:17 +0000

As your schematics grow in complexity, it isn’t always possible to draw simple connections between chips or devices. Sometimes it isn’t possible to put two parts next to each other like a pin header and I/O chip meaning that wires have to run all over the schematic to make the connection. That gets messy quick and not very easy to follow.

EAGLE automatically connects all nets (or wires) inside of a schematic when they have the same name. This means even if they are not physically connected on the schematic giving them the same name will connect them together. Using this trick, it is pretty easy to break up nets across the page.

Tutorials

Thu, 20 Dec 2012 23:36:19 +0000

arduino_tutorial_250px

basics_tutorial_250px

eagle_tutorial_250px

Baldengineer's Projects Overview

Thu, 20 Dec 2012 22:33:15 +0000

open_vapors_125px

quadcopter_125px

mso_demoboard_scope_125px

binboo_1_125px

IMG_3165

msgeq7_250px

8x6_matrix_250px

Making a 3D print with the MakerBot Replicator

Sat, 24 Nov 2012 00:21:33 +0000

Recently TechShop opened up one of their shops in Round Rock which is just a few minutes from Austin, where I live. TechShop is an awesome membership based workshop with a huge variety of tools useful for making things. On this holiday Friday I decided to spend some time with the MakerBot Replicator.

For some time I have been looking at a mini-tripod for my camera/iPhone so I could get pictures of projects while working on them. While browsing Thingiverse, I came across design files for such a thing.

First impressions of the Arduino Due

Fri, 23 Nov 2012 04:49:45 +0000

I’ve been working with Arduino boards for a number of years, as shown by the dates on some of my older blog posts. In that time I’ve only used boards based on the ATmega8 (like the Duemilanove or Uno). The Due is the first Arduino board I have used in what I would call the Mega form factor.

Physical Differences

I’m surprised by the size difference. I’ve always thought the original Arduino form factor was small, the Due is larger but still feels small.

How to Fix: Arduino is damaged and can't be opened

Fri, 23 Nov 2012 03:06:52 +0000

Open source software that isn’t signed by an identified developer can cause headaches upgrading it on OSX. While working with the Arduino Due the first time, I downloaded 1.5 Beta of the Arduino IDE and ran into this error:

“Arduino is damaged and can’t be opened. You should move it to the Trash.

Here’s why you see the “… is damaged and can’t be opened” dialog and how to fix it.

Reverse Resistor Color Code Generator

Wed, 07 Nov 2012 10:14:48 +0000

The other night I happened to see a tweet come across my twitter stream from Joe Walnes (@joewalnes) about a resistor color code tool he created. You can find it at the clever domain resisto.rs. Type in a value and see what the proper color code should be. This is great for when you need to go searching through a pile of resistors and want to make sure you have the code right.

Arduino: Fixing "Serial Port in Use"

Mon, 08 Oct 2012 09:46:16 +0000

Here’s a couple of quick tips to get around the Arduino IDE error message “Serial Port in Use.” These mostly apply to OSX, but since it is UNIX based, they may make sense for Linux as well.

List Open Files

Applies to: OSX, Linux.

The check to see if another process (like a previous run of avrdude) is holding the serial port open is easy on both Linux and OSX. Just open a terminal and run the command: lsof. The command will report back all files that are currently open by the operating system. UNIX-based operating systems do everything through files, so this command is useful to see what is keeping a serial device open. Since lsof gives a list of everything that’s open, and there are a lot of “files”, use grep to only list what is relevant.

Voltage Regulator Tutorial and Basics

Sat, 06 Oct 2012 20:41:30 +0000

Regulator Types

Fundamentally there are two types of voltage regulators: linear and switching. The names come from how they operate and how they achieve voltage regulation. Linear regulators tend to be a little cheaper to implement, but they aren’t as efficient as their more complex switching variants.

There are also some “cheap and dirty” methods that some designs use. Below is a brief description and example of each.

Linear

A simple way to think of a linear regulator is to think of it as an active series resistor. It will vary its effective resistance so that the output voltage remains the same. The upside to such a design is that it is cheap, simple to implement, and provides a relatively clean output. The downside is that the regulator dissipates a relatively large amount of power.

LED Matrix Arduino Shield

Sat, 06 Oct 2012 16:28:07 +0000

Status: Completed

GitHub: https://github.com/baldengineer/8x6-LED-Matrix-Shield

Abstract

After getting a couple of flashing lights working on a microprocessor, the next fun project is generally building some kind of Matrix. At first I built a 5x5 LED matrix which was relatively simple to solder together. When trying to make one much larger, the task because significantly more complex. That’s when I decided to build a LED Matrix Shield for the Arduino which did not use Charliplexing, like the LoL shield. I wanted something that was simpler to understand and (ultimately) code for. Unfortunately, 5mm LEDs means 8 columns x 6 rows, instead of the traditional 8x8.

Tutorial that goes over the basics of different regulators types

Sat, 06 Oct 2012 09:13:19 +0000

Digital ICs like microcontrollers, memory, and shift registers need a stable voltage source to make sure they work as expected. Most circuits are designed with a voltage regulator to accomplish this stability. In theory voltage regulators will vary their output to stay at a set voltage, regardless of how much current the load is drawing. As a load draws a little bit more current, the supply voltage will begin to sag. Conversely when the load is reduced the voltage may rise a little bit. Regulators work to eliminate, well minimize, this change.

Resonant Frequency Calculator

Fri, 05 Oct 2012 09:06:40 +0000

When working with components like capacitors and inductors it is always helpful to know how to calculate a resonant frequency. This Resonant Frequency Calculator is an excellent resource because it allows for calculating for Frequency, Inductance, or Capacitance. Sometimes plugging in what you know is faster than working through some algebra.

Check out the: Resonant Frequency Calculator.

BoxMaker: Create a new box - perfect for laser cutters!

Tue, 02 Oct 2012 09:53:27 +0000

When I was working on BinBoo (A Binary Clock), I decided I was going to create a custom enclosure with a laser cutter. The process took me a couple of iterations. The very first box I had cut didn’t hold together because I didn’t make enough “teeth.” The 2nd box included these and holds together solid.

After all of that work, I was pointed to BoxMaker which makes Laser Cutting a Box very simple. Check out how easy it is with these 4 steps.

Long Overdue LaunchPad Review

Sun, 30 Sep 2012 14:13:26 +0000

Recently I realized most of my projects were all Arduino-based. There are lots of other prototyping platforms available in the market, and the TI LaunchPad, based on the MSP430 is one of them. In fact, I have had one of these boards sitting in my box of stuff ever since they came out. At $5, they because an impulse purchase when I was buying some other stuff.

Are you a Scotty or a Geordi?

Wed, 22 Aug 2012 09:51:11 +0000

Martin Rowe over at Test & Measurement World asks an interesting question: Are you a Scotty or a Geordi? While both were engineers in the Star Trek universe, they approached their jobs with a different philosophy.

Which engineer are you most like?

[Via: Are you a Scotty or a Geordi? | Test & Measurement World.]

Raspberry coming to a Hackerspace near you

Mon, 20 Aug 2012 09:58:51 +0000

One of the Raspberry Pi Foundation’s developers, Rob Bishop, is heading out on a Hackerspace tour in the US. Looks like he’ll be visiting a couple of spaces on the west coast, east coast, and my home town: Austin, TX.

[Via raspberrypi.org Raspberry Pi Foundation US Hackspace Tour | Raspberry Pi]

Engineering Resource: Web Equation

Fri, 17 Aug 2012 09:05:59 +0000

Documentation, Documentation. Documentation.

It is always critical to document progress is a log book. If using an electronic tool like Evernote or a Blog, it can be difficult to document equations or calculations you’ve made in a project.

Vision Objects has put together a demo tool that allows for writing your equation in freehand which then uses image recognition to covert into LaTeX code.

Renesas Promotion Board for RL78/G13 | Renesas Electronics America

Wed, 15 Aug 2012 10:42:23 +0000

Renesas is offering a promotion version of their RL78 microcontroller. This offer is only available to their Sample Component account holders, but the process for signing up for a sample account is pretty straightforward. (There may be EAR restrictions with this board.)

If you are looking for a powerful processor that is an alternative to PIC or AVR processors, this board might be worth a look.

Note: It appears samplecomponents.com might have been compromised at some point in the past. Google throws a warning page up. Proceed at your own discretion.

Updated Eagle Tutorial

Tue, 14 Aug 2012 09:26:09 +0000

A couple of weeks ago I posted an EAGLE Tutorial on creating Ground Planes. That tutorial has now been updated with the above YouTube video showing the steps. Let me know if there’s anything else I can do to make it more clear.

Arduino: Getting Real Time Help

Mon, 13 Aug 2012 09:30:08 +0000

Note: The IRC Channel (along with all of Freenode) got nuked.

While the Arduino Project Team provides their official Arduino forums, sometimes real-time help is just a bit better. When that is the case, I encourage you to visit the freenode.net IRC channel, #arduino. While as of today it is not an official channel, there are a number of great people available to help.

You can find me under the nick “baldengineer”, big surprise, I know. Others like kline, Yoston and pwillard are also excellent people to ping with questions.

Arduino: Sending and Receiving Multi-Digit Integers

Mon, 30 Jul 2012 09:18:32 +0000

When Serial data is transmitted to an Arduino, it is sent one byte at a time. Even though you might type “123” in the Serial Monitor, that’s not quite what is sent. Instead the bytes “1” then “2” then “3” are sent. Once received into a buffer on the Arduino, these individual bytes need to be reassembled into something useful. The Arduino IDE provides Serial.readBytes() as one option. However, if you aren’t sure how many digits you are going to receive, this may not work. So another option is to use Serial.readBytesUntil() like so:

Arduino Example: Police Lights with millis()

Sat, 28 Jul 2012 18:00:20 +0000

Based on a question from Andrew on the initial Multitasking with millis() tutorial, this example shows how to create a Police-Light like strobe effect. The following code uses no calls to delay().

Code also available via Pastebin.org.


// English for which LED to Strobe
#define RED 0x0
#define BLUE 0x1

// Variable to track which LED is on
byte whichLED = RED;

// Where are the LEDs connected?
const int LED_Red = 7;
const int LED_Blue = 11;

// State variables for the LEDs
byte Red_State = LOW;
byte Blue_State = LOW;

// Some delay values to change flashing behavior
unsigned long switchDelay = 250;
unsigned long strobeDelay = 50;

// Seed the initial wait for the strobe effect
unsigned long strobeWait = strobeDelay;

// Variable to see when we should swtich LEDs
unsigned long waitUntilSwitch = switchDelay; // seed initial wait

void setup() {
pinMode(LED_Red, OUTPUT);
pinMode(LED_Blue, OUTPUT);
}

void loop() {
digitalWrite(LED_Red, Red_State); // each iteration of loop() will set the IO pins,
digitalWrite(LED_Blue, Blue_State); // even if they don't change, that's okay

// Toggle back and forth between the two LEDs
if ((millis() - waitUntilSwitch) >= 0) {
// time is up!
Red_State = LOW;
Blue_State = LOW;
whichLED = !whichLED; // toggle LED to strobe
waitUntilSwitch += switchDelay;
}

// Create the stobing effect
if ((millis() - strobeWait) >=0 ) {
if (whichLED == RED)
Red_State = !Red_State;
if (whichLED == BLUE)
Blue_State = !Blue_State;
strobeWait += strobeDelay;
}
}

State Variables

Red_State and Blue_State

Instead of using digitalWrite() directly, “state” variables are used to determine the state (on or off) of each LED. This allows logic inside the loop() to determine when the lights should be turned on or off. Each iteration of loop() will update the LEDs with a digitalWrite() based on this state variable.

EAGLE: Ground Plane (Polygon) Fills

Wed, 25 Jul 2012 09:05:46 +0000

Creating PCBs in Eagle is a straight-forward process once you understand how EAGLE works. In fact, most users can get up to speed enough to draw a Schematic and then layout a simple PCB. Making the connections between components is not only fun but can be a form of artwork.

Arduino: Toggling Outputs

Mon, 23 Jul 2012 09:00:13 +0000

Did you know it is possible to toggle the state of a Arduino OUTPUT pin using a single line of code? It’s true! It’s also possible to use digitalRead() on an OUTPUT pin. Assuming pin 13 was set to output, this single line of code will cause the LED to change state (or flash) each time it is called:


digitalWrite(13, !digitalRead(13));

Keep reading to understand how these two tricks work.

Simulation: Java Circuit Simulator

Fri, 20 Jul 2012 09:30:48 +0000

Do you know who Paul Falstad is? If not, you really need to get to know him, or at least, his web site. He’s a Geocacher, a Java programmer, and a Math nerd. [Editor’s Note: I don’t know Paul, I just read his web site.] The easiest book mark I can access in my web browser is a link to one of Falstad’s applets: A Circuit Simulation written in Java. A very functional simulator, at that.

OSX: Cathode, Best Terminal Ever!

Thu, 19 Jul 2012 13:26:26 +0000

Cathode from Secret Geometry is, hands down, my favorite Terminal Emulator for OSX. It is, in my opinion, (near?) perfect emulation of classic computer terminals from the 1980s. When using it, it reminds me of how far computers really have come. It is also one of the funnest ways to ssh into a remote host to edit a CSS file real quick.

I like keeping mine set to 14.4k baud emulation. The screen blur, when running Full Screen in Lion, almost makes me forget I’m using an LCD!

TMW: What's a half digit, anyway?

Wed, 18 Jul 2012 09:30:45 +0000

Martin Rowe over at Test & Measurement World published an article quite some time ago (1994) that explains what it means when a DMM claims to have “½” digits in their display. Intuitively, to me anyway, when I heard this I always thought of gas-pumps and how we pay for 9/10 of a penny with every gallon of gas (in the United States).

Eagle Tip: Command Shortcuts

Tue, 17 Jul 2012 09:30:31 +0000

A very little known feature of EAGLE is the ability to type commands instead of clicking an icon on the toolbar. This can come in handy when trying to perform multiple actions like selecting a group and moving it to a different part of the schematic. For me, since I use OSX trying to use function keys in EAGLE can be more cumbersome than typing a few letters.

Arduino: How do you reset millis() ?

Mon, 16 Jul 2012 14:00:42 +0000

The quick answer to “How do you reset millis()” is: You Don’t! And here’s why: if you did, it would potentially break most libraries and functions that rely on it. Generally the reason people want to reset it, is that they are concerned about rollover. Instead of focusing on resetting millis(), here is how to use it correctly.

Avoiding rollover and checking how much time as passed is done in a single line:

BinBoo: Building the front panel LEDs

Sun, 15 Jul 2012 16:14:06 +0000

Short build-lapse video of building up the front panel “matrix” used in BinBoo. This isn’t a true LED matrix. Instead it combining all of the LEDs into a common Anode, since the Cathodes are all controlled by individual outputs of the TLC5940.

I decided to wire up 16 LEDs, even though a binary clock only needs 11 or 12. This gives some flexibility to other uses for the box, like a random sci-fi computer pattern.

Part Stock Checker: Findchips.com

Sat, 14 Jul 2012 00:00:20 +0000

How many times have you been part way through ordering parts for a project when you realize the distributor you are using, doesn’t have any of the part you need in stock? Or maybe you want to design a kit and compare prices of parts. This is where findchips.com comes into play. This awesome free resource will scan inventory across a variety of distributors for a given part number. Not only will you see inventory levels but it is also a fast way to compare prices.

(Accurate) RTC Shield Rev2

Sun, 08 Jul 2012 00:02:39 +0000

Accurate RTC Shield with Kapton Stencil

For the past couple of weeks I have been working with the DS3231 Maxim. This chip is a I2C based RTC with an integrated temperature compensated oscillator and crystal.This means despite changing temperature conditions, it will maintain a very accurate track of time. If you’re interested in the first rev of the PCB, let me know. I have a few available. They are functional, however, the prototyping area came bad.I have a set of new ones with a proper prototyping area, reset button, and power LED in process.

Soldermask as an air freshener

Sun, 17 Jun 2012 04:39:08 +0000

While testing my Toaster Oven’s maximum temperature I learned a valuable lesson. Soldermask has a pretty limited lifetime when it is exposed to temperatures above 250C. Looks like I need to spend some time building a temperature profile and not just brute forcing.

Build description here: Open Vapors Reflow Oven Controller Project Page

Arduino Power Simulator

Sat, 16 Jun 2012 02:00:01 +0000

How to use this simulator:

Press the power button for the desired connections. For example, for USB-only, press the power button near the USB connector.
Enter a voltage for the enabled supplies.
Use “Reset” to start over.

The voltage at the other pins will be calculated.

Note: This simulator does not take into account current loading.

Examples

Enter 12.0 volts for the Barrel Jack. Watch what happens to Vin, 5V and 3.3V.
Enter 5.0 volts for the Barrel Jack. Watch what happens to Vin, 5V and 3.3V.

Reset

Open Vapors - Open Source Toaster Reflow Oven

Thu, 07 Jun 2012 00:34:25 +0000

Last Updated: 2017-SEP-07 Status: Completed

View Open Vapors Details on Hackster.io

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GiHub: Open Vapors Reflow Control Software Flickr Set: http://www.flickr.com/photos/9849051@N04/sets/72157630154132342/with/7390533878/

Abstract

My first attempt at making a reflow oven controller. The project is being released as an open source project, with the name Open Vapors.

Electronics

Parts list:

Toaster Oven (Goodwill)
Low Voltage Electronics:
- Maxim MAX31855 Thermocouple Amplifier (Adafruit Breakout)
- K-Type Thermocouple (from Adafruit)
- Arduino Uno
AC Line-Level Electronics:
- 15-Amp AC Wall Outlet (Home Depot) Replaced with IEC Outlet
- 15-Amp AC Wall Switch (Home Depot) Removed. May be replaced in next version.
- 14 Gauge Romex (Home Depot)
- Donor Cord from 6-Outlet Strip (to plug into wall) (Home Depot) Replaced with IEC Inlet
- Crydom SSR D2425 (Mouser)
  - Heat Sink
  - Thermal Pad
To Be Added:
- A couple of LEDs Added
- Buttons Added
- Character LCD Added, 16x2 to be replaced with 20x4 display soon.
- Custom Enclosure Workd

Schematic:

Overall Hardware

Accurate RTC Shield

Tue, 29 May 2012 03:32:24 +0000

Status: In Progress, Last Update: October 14, 2012

GiHub: https://github.com/jamesc4s/Accurate-RTC-Shield

Abstract

The DS3231 is a Precise Real-Time Clock from Maxim. It requires almost no external components and is temperature compensated. This chip solves some of the RTC issues associated with the DS1307. This Arduino shield will make it simple to add a RTC to any project, especially one where lost time is not acceptable.

Electronics

Parts list:

Fuelling Your Arduino - Thermal Look at Arduino Power

Fri, 25 May 2012 13:52:05 +0000

There are many options for powering an Arduino board. The designers did a great job of designing an auto-select circuit that makes it simple to power the boards. However, there are trade offs in how much power is available and how much power gets wasted. Australian Robotoics has a great breakdown of what an Arduino looks like under a thermal camera, when powered from USB and various external sources. I don’t agree with everything that is said in this article, but the pictures are very revealing (and cool to look at).

Build the Enterprise, in 20 Years

Thu, 24 May 2012 00:18:15 +0000

Can you can imagine what people thought about today, 20 years ago? Think of all the crazy things you (or others) thought we would be doing today. Like… Video phone calls from your car, perhaps?

Now use the same futuristc imagination to imagine if someone put together a plan to build a first generation NCC-1701 (“No Bloody A, B, C, or D”). Not just a plan, but a plan to do so in 20 years! If successful, we could get to the moon in a matter of days and Mars within College Football season.

Binary + Bamboo = BinBoo

Sun, 20 May 2012 00:22:14 +0000

Several months ago I started a project to build a Binary Clock, using a Laser Cut enclosure. The plan was to use Ponoko’s laser cutting service. Looking through the materials available, I decided to use Bamboo. Knowing I was going to build a Bamboo enclosure for a Binary clock, helped me come to the name BinBoo. Even though I call it a Binary Clock, it is actually a BCD clock…

Measuring Battery Capacity

Mon, 09 Apr 2012 17:19:01 +0000

Why is choosing a simple AA battery such a daunting selection process? Manufacturers are keen on giving their products different names and brag about the chemical technology that makes them up. However, it is nearly impossible to make package-to-package comparisons of the battery’s capacitor.

Denis Hennessay has a GREAT write up on Measuring Battery Capacity with an Arduino. In addition to full details on how his project works, Denis even shares the results of several AA batteries. Nice!

Why You Suck At Changing The World; Try Hardware - Upverter

Tue, 14 Feb 2012 02:05:28 +0000

T he iconic picture of a homemade case for the Apple I, the computer that changed the world, is a great image for Upverter’s post about… changing the world.

While most of today’s attention grabbing innovation comes from clever software apps, most forget that the hardware the apps run on require significant investments in engineering time. Making the next “multi core processor” is not a simple copy and paste function. Nor are there any “Getting started with complex digital design books” you can breeze through in a weekend.

The next step in wearable fabrics: fabric batteries

Wed, 08 Feb 2012 02:22:38 +0000

Researchers at the Polytechnic School of Montreal have figured out a way to turn a battery into a flexible material. Each strand of the “battery” is 0.6V. While exciting, it has one major drawback before commercialization: it isn’t waterproof yet.

How to: Weave a flexible battery into fabric material - Electronic Products.

New Digi-Key tool lets Engineers share schematics - Electronic Products

Fri, 13 Jan 2012 00:33:36 +0000

Tools like National’s (now TI) WebBENCH have allowed engineers to design power supplies without downloading any software for quite some time. Recently I got an account at Upverter.com. This web application is focused schematic capture with social sharing.

Just announced this week, Digi-Key is looking to enter this area with their new web based tool to share schematics, Scheme-It(sm).

I haven’t had a chance to put it through its paces yet, but I look forward to comparing to Upverter and Eagle version 6 soon.

MSGEQ7 Simple Spectrum Analyzer

Sat, 07 Jan 2012 08:51:32 +0000

Abstract

Mixed Signal Integration has a cool little chip that has 7 built-in bandpass filters. Run an audio signal through it and you have an instant audio spectrum analyzer! This is a simple spectrum analyzer based on an Arduino. Each of the 5 LEDs represent a single section of the chip’s 7 sections of audio spectrum.

MSGEQ7 on Adafruit Protoboard

Electronics

If you want to replicate this setup, here is the hardware you’ll need to get.

Arduino and MSGEQ7: Simple Spec Analyzer

Sat, 07 Jan 2012 08:01:44 +0000

Putting music signal into the Analog Input of an Arduino can be pretty boring. That is, unless you use a totally awesome chip like the MSGEQ7. This simple Spectrum Analyzer driven with an Arduino only takes a handful of parts. I used these incredibly awesome protoboards from Adafruit for the first time. The protoboard alone gives a fit and finish even before it starts!

Arduino Comparison Chart

Sat, 07 Jan 2012 05:30:45 +0000

When getting started with the Arduino, the shear number of board options can be intimidating. While the variety is a great option, it can be daunting to a new user. Many people are afraid of selecting the wrong board, or their budget doesn’t allow for buying multiple boards. Just looking at the “official” boards listed on the Arduino.cc site, there are 14+ different Arduino board types to consider. Then there are a variety of 3rd-party boards with their own uniqueness.

Added a G-Docs comparison chart to help pick an Arduino

Sat, 07 Jan 2012 04:37:44 +0000

Can’t decide which Arduino Board is for you? Have a board you want others to know about? This Google Docs Spreadsheet compares some of the key attributes of various Arduino boards. Whether you are trying to decide which one to buy or just want to know the differences, this chart can help.

Arduino Internal Pull-Up Resistor Tutorial

Fri, 30 Dec 2011 07:31:32 +0000

When hooking up switches or buttons to an Arduino I/O pin, sometimes the results might appear completely random. Sometimes it will appear as though there is a delay from when the button is pressed until the state of the pin actually changes. Other times the pin’s value will seem to randomly fluctuate from HIGH to LOW. Even more maddening might be as your finger gets closer to the switch, the pin’s state changes! The fix to these problems is simple: use the Arduino Internal Pull-up Resistor. Here’s how they can fix this problem and how you can use them with an Arduino board.

Spotting Arduino Clones

Mon, 26 Dec 2011 23:40:20 +0000

Open Source Hardware (OSH) means not only releasing devices, but all of the documentation associated with them. For some projects, this may include the actual CAD files used to produce the device. For example, the Arduino team produces not only schematics but the Eagle PCB CAD files for each of their boards. The great thing about such disclosure is that one can easily tweak the existing design for their own purposes. The downside is that nearly anyone can submit the exact same files to their own production house and have immediate clones.

LED Tutorial - Learn the basics

Wed, 21 Dec 2011 03:13:39 +0000

Nearly every consumer device makes use of the Light Emitting Diode (LED). This highly versatile device offers an easy way to add an indicator to any project while drawing a relatively small amount of current. Once their operation is understood, adding them to any project is a simple task. This tutorial is a simplified explanation of how a LED works and how to select a current limiting resistor. The LED tutorial here is enough to use LEDs in a project but is not intended to be a thorough explanation.

Video Tutorial: Buttons and Pull-Ups

Mon, 19 Dec 2011 05:20:26 +0000

This is a 4-minute video version of the Arduino Pull-Up Tutorial:

BinBoo - Binary Clock

Sat, 10 Dec 2011 08:33:23 +0000

Status: Completed Hackster.io Project Page: https://www.hackster.io/baldengineer/binboo Github Code: https://github.com/baldengineer/BinBoo GitHub Repository for BinBoo

BinBoo Binary Clock made out of Bamboo

Abstract

Binary + Bamboo = BinBoo. This project is my first attempt at making a laser-cut enclosure. Ponoko was used to cut the project which holds itself together. The LEDs are driven by an Arduino-based clock that incorporates a RTC1307, FTDI chip, ATmega328, and TLC5940.

Now that's an Apple Pie! - EMSL

Mon, 28 Nov 2011 15:55:22 +0000

What is more American than an Apple Pie? Why, a Pie designed in California, made in China. This is one pie I’d like to jailbreak. Is applying too much heat to this pie considered an upgrade? Okay, that’s all the lame puns I have for this laser cut pie.

Evil Mad Scientist Labratories provides a tutorial on how to bake a Mac Mini Style Apple pie, complete with Laser Cutting Instructions. Yeah that’s right, a laser cut pie.

BinBoo Control Board, Alive

Sun, 30 Oct 2011 05:07:56 +0000

The control board is up and running, with some re-work. Shown next to the working LEDs is my original inspiration. Last Christmas my brother gave me the ThinkGeek Binary watch. Since then I’ve been fascinated with binary clocks. Finally I had an idea that can help with other projects.

Now that this board is up and running, I am looking forward to assembling the case. The case is being built by Ponoko. Based on Google SketchUp, it is going to look like this:

The Making of Arduino - IEEE Spectrum

Fri, 28 Oct 2011 16:41:57 +0000

Even knowing that the name Arduino was rooted in Italian, I have often wondered what it meant. David Kushner of IEEE Spectrum has a great write-up on the beginnings of the Arduino project.

Great read. The most surprising thing to me is that over 250,000 official boards have sold since 2005. That isn’t counting clones and stand alones. Wow!

Binary Clock Control Board

Fri, 28 Oct 2011 01:38:10 +0000

Untitled, a photo by JamesC4S on Flickr.

Assembled control board. The processor is an ATmega328, RTC is DS1307 RTC, and LED driver is a TLC5904. There is also a FT232RL on the back side for USB to Serial connection, however, it doesn’t appear to be working.Next I’ll need to turn on the RTC and make sure it can actually keep time.

One million ARM cores to simulate brain at Manchester

Fri, 08 Jul 2011 14:22:28 +0000

The lead hardware designer of both the original ARM core and the BBC Micro Computer, Professor Steve Furber, is leading an effort to simulate the human brain with ARM cores. Custom chips with 18 cores each will be used. Check out the story at Electronics Weekly for more information: One million ARM cores to simulate brain at Manche`ster - 7/8/2011 - Electronics Weekly.

Space Shuttle Infographic

Thu, 07 Jul 2011 15:23:53 +0000

Space Shuttle Infographic

A long time fan of the NASA Space program, the last shuttle going up is a little bit sad. Artist Alberto Cuadra has put together this infographic about the shuttle. Originally created by the Houston Chronicle. (Citation missing, please comment if you have one!)

Diodes adds 5V capability to Glue Logic

Thu, 23 Jun 2011 14:16:11 +0000

These days it is pretty rare to see a press release from a semiconductor company touting 5V TTL capabilities. Diodes is upgrading their 5V TTL logic as reported by Electronics Weekly. While the 5V operating will easily appeal to hobbyist, the package sizes may not. They are not through-hole components. However, the 74ACHT series will provide you surface mount solutions for AND, NAND, OR, NOR, XOR, Inverter, and Schmitt trigger glue logic.

Tamper resistant memory

Tue, 07 Jun 2011 23:17:55 +0000

Watch an episode of NCIS or CSI and you might get the impression that hacking electronic devices is a simple way to learn all you need to about a person. While these shows tend to gloss over the science of the forensic work, the truth is, most electronic devices only rely on obscurity to keep data safe. Here is an article from Cambridge researchers discussing how to read contents using lasers (but not feverish typing on a keyboard for software that is clearly graphical in nature.). That sound crazy right? Don’t forgot Princeton has guidelines on security based on the fact you can freeze RAM to extend its retention.

NASA Space Shuttle Owner's Workshop Manual Book Review

Wed, 20 Apr 2011 14:33:30 +0000

Over at Universe Today, there is a review of the book titled “NASA Space Shuttle Owner’s Workshop Manual.” When I first started using the Internet (over dial-up at 28.8kps), I came across JPL’s website. It lead me to the Operations Manual and Reference Guide for the Space Shuttle. At the time I couldn’t believe such information was available to the public. Then I realized, didn’t the public buy those machines in the first place? It is a shame we are garaging them.

Apple A5 vs A4 Floorplan Comparison

Wed, 16 Mar 2011 15:02:11 +0000

Apple’s latest magic trick was upgrading their previous A4 chip into a dual core variant, the A5. This chip powers the recently announced iPad 2 and is likely to be in the upcoming summer release of the iPhone 5 (4s?) The folks at Chipworks have done some reverse engineering (which may be using actual magic) to see what the inside of the A5 looks like… all 2.9Million gates of it.

EW: Single-chip GPS IC

Thu, 10 Feb 2011 07:13:14 +0000

Coming Q3 of 2011, ST-Micro will begin selling a Single-Chip GPS IC called the Teseo II. It has an ARM core integrated into it, which should help reduce the time it takes to get a fix, and simplify integration into any hardware project.

Pricing is set at $6 in volumes of 500k, so for hobby work it may be a cost/time trade-off.

ST selling single-chip GPS IC. - 1/27/2011 - Electronics Weekly.

Arduino UNO SMD Amnesia

Thu, 20 Jan 2011 16:10:22 +0000

On the Janurary 15, 2011 edition of Adafruit’s “Ask An Engineer” live video chat, I heard LadyAda mention something about “Arduino Amnesia.” After investing the situation a little further, it turns out there are some Issues with the new Arduino UNO Smd edition.

A bug in the new bootloader can be triggered on power-cycle causing the SMD version of the board to not load the previously stored sketch. The good news is there is already a fix for the bug. Either return the board to your Official Distributor or use a ISP to program the new bootloader.

millis() Tutorial: Arduino Multitasking

Fri, 07 Jan 2011 04:01:55 +0000

After learning how to flash a single LED on your Arduino, you are probably looking for a way to make cool patterns, but feel limited by the use of delay(). If you ask in the forums, you get told to look at the “Blink Without Delay” example. This example introduces the idea of replacing delay() with a state machine. If you’re confused how to use it, this tutorial is setup to take you from blinking two LEDs with delay, to using an alternate method, right down to how you can use millis().

IBM's 2010: 5 for 5

Thu, 16 Dec 2010 15:24:13 +0000

From the company that brought us, “There is a worldwide need for no more than 5 computers”. IBM is announcing 5 Innovative Technologies we will see over the next 5 years.

In summary they are:

3D Communications
Batteries that use air to recharge
Citizen Scientists (Sensors Everywhere!)
Personalized Commuter Information
Smarter Energy Grid

iPad/Arduino Controlled KegBot, by Yelp

Sat, 16 Oct 2010 16:25:03 +0000

Engineers at Yelp have put together an Arduino and iPad controlled Keg-o-rator. By swiping their RFID they can track how much a person is drinking, collect statistics about how others enjoyed the beer (by rating it), and maintain a leader-board of the office. Everything used in the project is based on off-the-self components. My guess is that they are communicating between the iPad and Arduino over the iPod Dock’s i2c interface. It looks like they are using the PodGizmo iPod Dock Conntector Breakout board available at Kinetka Systems. Drink up!

Purdue Boilermakers are MAKERS!

Thu, 14 Oct 2010 15:46:07 +0000

George at nbitwonder caught this outside the Armstrong Hall of Engineering Purdue while walking to class. The signs read:

I think work should be about making things work. Better. Faster. Smaller. Smarter. So I build bridges between what’s known and what’s not. I tinker. I toil. I write poetically in an abundance of languages (including code). I hack. I dissect. I have an insatiable desire to un-complicate the complicated. I am easily inspired. I believe that just because it hasn’t been thought of doesn’t mean it won’t be. Potential is my thrill ride. Imagination is my most-used tool. I am a maker, and I am what moves the world forward.

LED Calculator

Wed, 13 Oct 2010 11:44:05 +0000

Rob ’linear’ Arnold has put together a fantastic LED Series/Parallel Wizard. Not only will it calculate the current limiting resistor you need, it will draw a circuit diagram, and give you full statistics on power usage. If you are just getting started with Electronics, this is a great resource for learning about LEDs. Experienced users will enjoy a quick check of their math.

The array above is designed for some Blue LEDs I have laying around. I wanted them to run with 15mA which is well below their max, but still very bright. In this case 1/4W resistors should be fine and each should be 120 ohms. I should be safe hooking this array up to an Arduino since each LED will draw less than each I/O pin can handle AND total current draw is only 60mA.

What Capacitor Measurements Mean

Tue, 05 Oct 2010 12:57:00 +0000

Electronics Weekly has invited Dale Cigoy of Keithley Instruments to talk about how capacitors work. Since capacitors are part of almost any Electronic circuit or project, it is a good idea to understand these basic components a little more. The article is titled “Seeing how capacitors work is invaluable.”

EDN: ICs could run on heat waste

Thu, 30 Sep 2010 20:05:39 +0000

Joseph Heremans and Roberto Meyrs at the Ohio State University have been studying materials that could be used to turn heat from ICs into electricity. The research is focused on thermo-electricity and spintronics. In theory, this could mean mutual benefits to heavy processing: more effective heat removal from processors while generating the electricity they need to operate.

“All of the computers we have now could actually run much faster than they do, but they’re not allowed to - because if they did, they would fail after a short time,” Myers said in the statement. “So a huge amount of money in the semiconductor industry is put toward thermal management.”

8x6 LED Matrix Shield for Ardiuno

Mon, 27 Sep 2010 01:34:40 +0000

This is a quick video demonstrating the LED Matrix Shield for the Arduino. This Matrix is an 8x6 “Normal” matrix. (It is not Chairleplexed.) Blue LEDs were used to give it a brilliant hue and to provide another source of light in dimly lit apartment homes. Only one row of the Matrix is lit up at one time. This is done to save power and because the ATMega processor of the Arduino cannot source or sink more than 200mA of current.

Annotated Arduino UNO

Sun, 26 Sep 2010 23:26:30 +0000

westfw of the Arduino Forums has put together a nice Flickr Annotation of the New Arduino UNO. A couple of changes have been made from the previous Duemilanove. Interestingly they have left pads for either a crystal or resonator on the board. This may allow the end-user to use a crystal for more accuracy without adding additional cost for everyone else.

Matrix LED Shield PCB

Fri, 24 Sep 2010 15:48:25 +0000

The PCB for my very first Arduino shield arrived today from BatchPCB. At first glance everything looks good. The silkscreen with my name and web address didn’t come out so well but that was probably my fault on trying to fit in too much.

Looking forward to assembling then with some Blue LEDs!

EW: True Random Numbers from a handful of gates

Wed, 22 Sep 2010 02:54:27 +0000

Random numbers are a relative concept. In general, random numbers used in digital electronics are called Psuedo-Random sequences. There is a defined algorithm that is used to generate the sequence and does not actually occur in nature. In applications like Flashing a LED, this method is fine. However, for any level of encryption this is unacceptable.

Steve Buch at Electronics Weekly writes about how researchers Dr. Marie O’Neill and Dr. Jiang Wu at the University’s Institute of Electronics and Communications Information Technology (ECIT) has developed methods to generate true random bits digitally.

Inside the iPhone 4 Gyroscope

Wed, 30 Jun 2010 15:10:58 +0000

One of the major feature updates for the iPhone 4 included a gyroscope. There are two applications that a gyroscope can be used for: keeping an object in balance and providing precise positioning data. Obviously, the intended application in an iPhone is improved positioning and control of software objects. One of the questions I had about the iPhone 4 was whether there was something (very tiny) spinning inside of the iPhone or if the device was solid state. Until now, I had no idea that solid state gyroscopes existed. Engineers at iFixIt, with help from Chipworks’s Electron Microscope, have done a teardown of the iPhone 4’s MEMS based Gyroscope.

Flexible Print Circuit version of Arduino

Wed, 30 Jun 2010 14:57:43 +0000

The folks over at Seedstudio have created a first for Arduino: a FPC version! In the past, it was very common for this material to be used as interconnects between circuit boards in production products. The flexibility makes it simple to use and the ability to attach components directly saves space. These are just prototypes, but Seeedstudio is looking for ideas to help move into higher volume production. Who is going to make the first Arduino watch?

Lighting up fiber with Darkness

Wed, 30 Jun 2010 14:43:25 +0000

Electronic communications systems are made up of three basic components: a transmitter, a receiver, and a transmission medium. Use a video game system with a wired controller as an example. The controller is a transmitter, while the console is a receiver, and the wire that connects the two is the transmission medium. This wire is typically made up of copper. The distance from a couch to your tv is relatively short compared to the distance two continents separated by an ocean. For this distance fiber optic cables are used. Instead of electrical signals being transmitted, lasers are used to generate light across fibers of glass.

RTW Blog

Tue, 01 Sep 2009 18:03:22 +0000

In July, I left on a trip that took my friend and I around the world. While traveling, I kept a blog of the trip at trip.cmiyc.com.We visited New Zealand and Australia during winter. After that we spent a week swimming and sunning on beaches in Bali. Then we made some quick stops to Tokyo, Bangkok, and Egypt. In Egypt, we got to ride camels and see the Pryamids. While in London, I met with another friend for a few days before visiting Budapest and Ireland. Pictures can be found on my Picasa Albums. Now that the trip is over, it is time to get back to work. :)

TLC5940 Painter PCB

Sun, 05 Apr 2009 19:11:09 +0000

TLC5940NT Painter Board

This screen shot is an all-layer view of my TLC5940 painter board. The 1st draft featured two TLC5940s, but I decided it made the board too large. Instead, I wanted the ability to mount the painter boards around the LED’s shadow box. This should make routing all the wires much easier.

The board is approximately 1.25in x 3.5in. All signals have been routed on the top or bottom layers. Most of the components will mount on (or through) the top layer. Some coupling caps have been put on the bottom. Initially the board had a 7805 built in, to provide +5V to the painter boards and the arduino. Instead, I ripped that out and plan to use the regulator on the arduino instead. There are 6 data and power ports. SER-IN will either come from the host arduino, or from another painter board. SER-OUT contains 2 less pins than SER-IN. I included two surface mount buttons in the layout, so I could get some inputs back to the Arduino, these are entirely option and will only work on a single board.

Row Your Boat, Part 1

Thu, 26 Mar 2009 02:28:39 +0000

This pattern is called Row Your Boat. As one of the strips starts to get brighter, a nearby strip will join in the fading. After completing a fade cycle, they start switching colors. There is a random strobe thrown in there as well. The first 10 seconds are with a diffuser (piece of paper), the last 10 seconds are without. The final panel will use a diffuser.

The colors have no correction yet, so red is really dim and green is really bright. It looks like one of the channels of my TLC5940 is going bad. The center LED strip’s blue is very dim. I’m not going to look much into it right now though. Instead, I will wait until I fab a PCB for the 5940 (this weekend?)

Getting gEDA running on OS X

Mon, 23 Mar 2009 22:38:43 +0000

Quick schematic in gschem running on OS X.

In an attempt to find a free set of schematic and PCB tools for hobby work, I looked back at gEDA. The last time I used it was when the project first started, years and years ago. I was happy to see that OS X had a set of fink packages for the gEDA suite. After figuring out how to get X11 in Leopard (since I didn’t include it when I installed 10.5) and install fink, getting gEDA going was a snap. The user jluciani in the Arduino forums has provided some free pcb footprints he has used from previous projects.

Captain Awesome: FTW!

Wed, 18 Mar 2009 02:28:40 +0000

Landing on water isn’t easy. In fact, most aerospace engineers never considered it possible.

see more Political Pictures

LED Strip Fun, First Try

Sun, 01 Mar 2009 15:28:33 +0000

Initially I tried to get a LCD screen working with my Illuminato based Arduino. After a couple of attempts I realized two things: 1. The Iluminato is not ready for prime time. and 2. I burned out the LCD. So I decided to move on to the LCD strips I have from Sparkfun.

The program is pretty simple since I am using the PWM outputs. The first video is with the lights off and the second is with the lights on. I need work out the min / avg / max for the different colors. The next step is to create two columns (or rows) of LED strips, using a buffer chip.

5000 Miles (8050Km) to Snow

Wed, 18 Feb 2009 00:25:40 +0000

This morning I woke up somewhere in Southern Austria.When I looked outside my window, I found a very heavy snowfall.My local colleagues tell me that we received somewhere between 50 and 60cm of snow.That is between 10 and 20ft, based on what I can see.

Four weeks ago, I developed a rash (no, not that kind).My dermatologist (www.webmd.com) concluded it was a result of being exposed to extreme dry and cold conditions.In fewer words, I was allergic to Colorado.So, I moved from Colorado Springs back to Austin.Despite growing up in Northwest Indiana, which received significant amounts of snow fall and ridiculous below freezing temperatures, I am very warm blooded.After moving just 2 or 3 weeks ago and becoming acclimated to warm weather again, I found myself headed to Europe on a business trip.

Quick Re-Hello World

Wed, 04 Feb 2009 05:13:39 +0000

After a long time posting to cmiyc.com, an upgrade to Wordpress, and two physical moves I just wanted to make sure the blog still works….

MacCaching Build #97

Thu, 31 May 2007 13:11:46 +0000

Download: maccaching_build_97.zip(5.3mb)

Minor change in how uploads are handled (to correctly support USB). This is the only different from 96.

Serial Port List Utility

Sun, 27 May 2007 05:40:21 +0000

Download: OSX Serial Port Check (1.2mb)

A simple utility that checks for all of your Mac’s serial ports and copies the information to your clipboard.

Why are you spamming me?

Wed, 10 Jan 2007 03:01:56 +0000

Nobody at “cmiyc.com” or “cmiyc.org” will send you email. In fact, I don’t even have an outgoing mail server setup. So if you receive emails from me, a spammer is forging my domain name in the email headers.

There is little that can prevent this, since it is something that happens in between you and I. All I can say, it is perfectly safe to drop any emails that appear to come from “cmiyc.com”.

Announcing: v0.5.0 of MacCaching

Sun, 07 Jan 2007 23:12:34 +0000

Version 0.5.0 of MacCaching can be downloaded from its own site at maccaching.com.

Here is a direct link to MacCaching 0.5.0.

New Beta Build Available

Wed, 27 Dec 2006 05:33:02 +0000

Visit the MacCaching latest-build page for a “Christmas” build. Among the new features is an iPod Paperless Caching feature!

The Blog Has Moved…

Mon, 11 Dec 2006 00:11:51 +0000

MacCaching has taken off a little faster than I had thought. Turns out many others are interested in Mac-Geocaching software. Since cmiyc.com was a originally my personal site (and really my web sandbox), I’ve decided to move MacCaching. The first thing to go is the Blog. The main site is now: maccaching.com and the blog is maccaching.com/blog. Everything else (news, downloads, and latest) will be mirrored between the two sites for a month or so.

Geocaching 101 by Lifehacker

Sun, 10 Dec 2006 01:01:35 +0000

Lifehacker has put together a description of what they call the modern day pirate hunt. This is their way to honor the soon to be DVD, Pirates of the Caribbean movie coming to DVD. It describes the basics of Geocaching. This is probably a good article for friends you’d like to introduce to Geocaching.

Quick Fix: v0.2.4_r1

Tue, 05 Dec 2006 14:42:19 +0000

Turns out my complier isn’t creating i386 (Intel) binaries correctly. So this is a quick fix for Intel users. If you already downloaded 0.2.4 and have a PPC-based Mac, there’s no need to download this one.

Unite For Diabetes - Geocaching.com's Travel Bug Promo

Mon, 04 Dec 2006 17:06:22 +0000

On today’s PodCacher.com pod-cast I heard that Groundspeak launched the Unite For Diabetes Travel Bug Promotion to help raise awareness for diabetes worldwide. They have a limited number of travel bugs which they will ship anywhere in the world, for free! The goal for each Travel Bug is to reach its city and circulate throughout the city’s geocaches, spreading diabetes awareness as it goes.

There is a sign-up page there if you’d like to try get one of the specially designed travel bug tags with a blue diabetes ring. Visit the main site for more information.

v0.2.4 is now available

Mon, 04 Dec 2006 04:14:38 +0000

0.2.4. adds some key functionality while fixing a number of bugs. All reported bugs have been fixed, so if you see a problem, let me know. Download it from /dl/

Here’s a few things added: + Links to Google Maps and Geocaching.com (double-click on a Cache) + Coordinate Editor Allows all Text Fields to be Edited (75% Complete) + .LOC files now supported (Geocaching.com Data Files) + Drag/Drop files (GPX or LOC) into Cache List + Transfer of select CacheLists (instead of entire Library) + Check for Updates Implemented + GPSBabel now included with Application Bundle

Child's Play Charity

Sun, 03 Dec 2006 15:58:05 +0000

This Year’s Child’s Play Charity is underway. Here is a description from their site: “Since 2003, gamers have banded together through registered Seattle-based charity, Child’s Play. Over a million dollars in donations of toys, games, books and cash for sick kids in children’s hospitals across North America and the world have been collected since our inception.”

Video game players tend to get a bad rep because of the media’s great job of highlighting a few bad stories…

Child's Play Logo

Sun, 03 Dec 2006 15:53:08 +0000

New Latest available.

Wed, 29 Nov 2006 04:14:05 +0000

The new “Latest” Release contains the following major changes: \* In the Edit Coordinate dialog (double-click on one), links to Google Maps and Geocaching.com work! Check them out! \* A dialog will pop up asking which CacheList you want to transfer to your GPS, instead of defaulting to all. \* You can edit existing Caches by double clicking on them. (This is also a good way to view the extended Geocaching.com information.) \* gpsbabel is now embedded in the App bundle. You don’t have to locate it, I’ll always put it there.

Get the latest bugs, er, features.

Sat, 25 Nov 2006 08:14:47 +0000

Since this software is in constant development, I thought I’d start releasing my “in between versions.” These are basically the builds I use while I’m busy breaking the development code to do something new. If you run a “latest” release, please let me know what issues you encounter. From now on, they’ll simply be put at this link: MacCaching_latest-build.dmg.zip.

To see the Modified date look at the blank directory: /dl/.

LOC to GPX Converter

Fri, 24 Nov 2006 12:28:29 +0000

geocaching.com uses LOC files for its caches. If you are a premium member, then you have access to the GPX files. MacCaching was made around the GPX files. You can load a single cache or you import a pocket query. Initially, MacCaching didn’t support LOC files, so I created this wrapper around gpsbabel.

It is now a standalone LOC to GPX Converter for OS X (2.7mb). Simply drop your LOC file onto the program’s window and a GPX will be generated.

No caching at the Virgin Island National Parks

Fri, 24 Nov 2006 06:03:06 +0000

Officials for the Virgin Island National Parks (VINP) are concerned about the effect Geocaching has on their parks. The officials appear to want to make things right and find a way to regulate caching. For the time being though, caches aren’t allowed inside of VINP boundries. This article serves as an important reminder. You can not just assume you have permission to place a cache! Public lands like parks are often regulated to protect the land. Even though it is public, you can’t just place caches there.

MacCaching v0.2.3 Released!

Tue, 21 Nov 2006 19:57:46 +0000

This one took me much longer to complete than I had planned. I decided to go back and fix things I was putting off. For example, the Preferences work now and the program won’t crash if you delete your Library. Download v0.2.3 Here.

This is the first Mac application I’ve ever created, so I am learning as I go along. You’ll notice the new disk image only has two files (well 3 with the README). You should be able to drop these into your Applications folder and be off. The only gotcha I haven’t worked out on first launch is locating gpsbabel. You have to do that manually (sorry).

Arkansas commissioners not ready for Geocaching.

Fri, 17 Nov 2006 21:36:31 +0000

Re cently the Game and Fish panel decided not to allow Geocaching permits on agency lands. Doyle Shook, Chief of Wildlife Management, stated they simiply aren’t ready yet.

Makes me wonder if permits will be required for placing caches or finding them.

v0.2.3 is almost ready

Thu, 09 Nov 2006 06:12:03 +0000

Tonight I spent most of time working on usability issues. For example, now you can select multiple caches to delete or move to a playlist. Also fixed the navigation in the cache list, so the keyboard’s arrows can be used now. There was a bug when deleting caches from the main library. They didn’t get deleted from the Cachelist.

I’ll package up another release once I finish with the Preferences Manager (1/2 done).

Milestone: Cache named after me.

Wed, 08 Nov 2006 03:20:51 +0000

The other day I had some time between client visits, so I set out to look for a couple of caches. The cache, GCPA29, was listed as a nano cache. This was my first one. Right before giving up on it, I accidently moved it. I thought the nano cache was a rubber screw head cover. Imagine my surprise!

The cache originally had no name, so I suggested “Ticker Tape!” (You’ll notice that it is now named, Ticker Tape…)

Paperless by iPod

Wed, 08 Nov 2006 03:14:13 +0000

Next week i start traveling for an extended period. One of the reasons I started this project was to help with caching in new areas. So I’m working on importing a pocket query from geocaching.com. Right now things like the descriptions and hints are lost on import. I’m working to not drop those.

In addition, I’m going to put hooks in for iPod syncing. You’ll have the option of sync through your Address Book or through the “Notes.” The trade-off is, your address book can become full of caches. However, to use the “Notes” you’d have to enable Disk Usage in iTunes.

Bomb Squad Visits a Cemetery

Tue, 07 Nov 2006 03:17:18 +0000

From the St. Petersburg Times: “The two mysterious visitors huddled around the sign to Dunedin Cemetery, poking and snooping around.

Someone at former Dunedin Mayor John Doglione’s funeral saw the couple and called authorities.”

Source: St. Petersburg Times.

Quick follow-up release: 0.2.1

Thu, 02 Nov 2006 18:10:02 +0000

After “releasing” 0.2, I realized there were a couple of hard-coded things which don’t work on other systems. I’ve resolved them. You can now delete waypoints from the library (or a playlist.) The only two ways to add waypoints is from a new “Download” or Importing a GPX file. Also I fixed the bug where the program wouldn’t actually call gpsbabel.

MacCaching v0.2.1 is now available for downloading (2.5mb).

Next on the list is “sticky” preferences.

Podcacher Logo

Thu, 02 Nov 2006 00:20:13 +0000

Podcacher - Geocaching Podcast

Thu, 02 Nov 2006 00:15:34 +0000

The other day I ran across a great podcast called Podcacher. As of this week, they are up to 76 shows. Sonny and Sandy put on a great show with all sorts of Geocaching related information.

Their podcast is the most professional sounding non-professional podcast I’ve heard. (Even before their latest equipment donations!) If you search iTMS for “Podcacher” it’ll come up. Or head over to their blog and check out the Forums.

Halloween Release

Tue, 31 Oct 2006 05:55:03 +0000

The screenshot isn’t up to date, I didn’t spell check the README, the icon doesn’t show up, and the list of known issues is longer than the features. However. If you’re looking for a Universal Binary that lets you communication with a Garmin GPS, you’ve got it. The best part, it is free. Not $100, not $49.99, or not even twenty-bucks.

Granted, it doesn’t do a whole lot…. yet.

I’m targetting an update every 2 weeks until 1.0.0.

Progressing toward v0.2

Mon, 23 Oct 2006 19:00:18 +0000

I made significant progress this weekend towards v0.2. I am able to download (transfer) GPS coordinates from my Garmin eTrex Venture and import them into the library. I paused work on the Library manager because of a bug in my development enviornment. Since I discovered a work-around, I will move back to completing the v0.1 features. After the final Library features are implemented, I’ll work on coordinate uploads. Once I can upload and download coordinates, I’ll release v0.2.

Roadmap to v1.0

Mon, 23 Oct 2006 18:50:55 +0000

0.1: - Basic Libary Support - Basic Playlist Support - Integrate the coordinate converter utility

0.2: - Initial gpsbabel support. Upload/Download - Expanded GPX support (geocache namespace support) 0.3: - Actual Syncronization

Somewhere in 0.3 - 0.9: - “Sync to iPod” for Paperless caching - Nested Playlists. - Feedback system (e.g. type of unit being used) - Check for updates feature - Google Maps integration - Copy / Paste -> Parse pocket query emails - Getting Started Wizard/Assisant

Version 0.1

Fri, 13 Oct 2006 23:21:13 +0000

MacCaching is best describe as iTunes for Geocaches.

When I received my Garmin eTrex Venture for my birthday, I was dissappointed to see the software selection for my iMac. GPSBabel has a OSX port, but it didn’t work with my unit. GPS Connect looked promising, but doesn’t appear to be in active development.

As I got started with Geocaching, I found I wanted a way to organize all of the little GPX files litering my desktop. I also thought it’d be nice if I had a central place I could come back to and see the list of caches I’m currently seeking. In other words, something to link me back to geocaching.com.

penny-backer bridge.jpg

Fri, 14 Jul 2006 01:07:31 +0000

About CMiYC.com

Mon, 03 Apr 2006 03:34:37 +0000

CMiYC is my online name which I have used for over a decade. I first started using my online name during the BBS-era. The cyberspace name meant, good luck finding me since I wasn’t online as much as most people. I would leave it as a tagline. When I got my first car, a first-year Dodge Neon, I would street race. Not exactly the smartest thing ever, mind you. These days, I keep it on the track.

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Retro Repairs RoundUp Appearance

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NXP's MCX FRDM Board Hands-On

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April 17, 2024, at 1:00 pm CDT

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Mega IIe Supercon Links

Social Media Links

Slides

Thank You

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Difference between flux (for soldering)

Oscilloscope Trigger Primer

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Out of context screenshots are out of context

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UPS ESR Battery Measurements | Workbench Wednesdays #32:

Essential Consumables for Building Circuits | Workbench Wednesdays #31:

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Behind the scenes

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