ESP8266 on Bald Engineer

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.

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.

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.

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.

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

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.

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.