Measure PWM Current with a Modified Moving Average

How do you measure a signal that keeps changing?

Measure PWM Current with MMA

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).

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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’!)

Tutorial Contents

The video starts with a couple of (mixed) motor examples. Do you know what a “stator” or “rotor” is? If not, that’s okay because that’s one of the first things we explain. After that, we add part like the commutator and brushes to make the Brushed DC Motor. After that is control with a transistor and an explosive reason you need a protection diode. 🙂 Then we show how an H-Bridge Works. Lastly, the advantages and disadvantages of this motor type.

You can see the full Brushed DC Motor Tutorial on YouTube or on the AddOhms page.

Social Media Guide for Engineers, a How-To

Click here to find the 1 magic trick to using social media ;)

Social Media Guide for Engineers

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.

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3D Printer Tips I wish I knew 3 years ago

Here's how I stopped getting annoyed

3d printer tips by bald engineer

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.

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5 Common Arduino Programming Mistakes

Code compiles but doesn't work? Check these 5 mistakes.

5 common arduino programming mistakes

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.

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3 Way Camera Shoe

Thingiverse.com
17-JUL-2016

DSLR Shoe AdapterWhen 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!)

Your ideas for test equipment alternatives

test equipment alternatives

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.

Sometimes when working on a project, whether hobby or professional, you just don’t have the tools you need on hand. Or worse, you cannot afford it. So here are some of the responses you all sent me.

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Adafruit Temperature Sensor Comparison

10 Options, which one is right for you?

adafruit temperature sensor comparison

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.

I couldn’t find a comparison in my quick search, so I built my own comparison table. Here’s my chart for an Adafruit Temperature Sensor comparison of their breakout boards.

adafruit temperature sensor comparison chart

Updated: 2016-JUL-27

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IEEE EMC 2016

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.

James at IEEE EMC 2016

For the IEEE EMC 2016 conference, I am attending on behalf of my day job. I’ll be on the tradeshow on Tuesday, Wednesday, and Thursday. Stop by the KEMET booth (#903) to learn about AC Chokes, EMI Filters, a flexible EMI shield, EMI Cores, and X/Y Safety Capacitors. Since I’ll be in Ottawa Monday through Friday, let me know if you’d like to meet up.

Finally, check out the EMC Society website if you’re interested in the group behind this conference.

Date:July 25, 2016—July 25, 2016
Appearance:IEEE EMC 2016 in Ottawa, ON
Outlet:IEEE EMC 2016
Location:Ottawa, ON Canada
Format:Other

Arduboy Review and Hands-On

What's great about combining Arduino with Retro Video Games

Arduboy Review Combing Arduino and Gameboy Banner

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.

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