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I Wrote Another Book

Building Your Own Electronics Lab

Building Your Own Electronics Lab

I wrote another book.  This time it’s about building your own electronics lab, titled Building Your Own Electronics Lab.  It gives the reader a gentle introduction to electricity and electronics and how to safely learn and play with them.  Basic tools and components are discussed and some simple starter projects are presented.  The main idea that I tried to put forward is that the electronics hobby is fun.  It’s also fun to share with others.

Both paperback and e-book versions are available from, or find it at your favorite bookseller using the ISBN 978-1430243861.

Dale Wheat’s USB to TTL Adapter

Photo of Dale Wheat's USB to TTL adapter

Dale Wheat's USB to TTL adapter

Yes, that’s what it’s called. I’m not too creative when it comes to naming products. I try to be descriptive; sometimes I succeed.

This is a minimalist USB-to-TTL adapter for use on a solderless breadboard. I designed this to use with my Breadboard Arduino class. It’s based on the FTDI USB UART chip, which is the same, identical chip used on “real” Arduinos, so it uses the same, identical drivers and works on most PCs. The only differences are that it is tiny, it plugs into a breadboard and lines up with the RESET, TXD and RXD pins of an ATmega328 chip (the Arduino main-brain) and it says “Dale Wheat’s USB to TTL” when you plug it in the first time. I make these here in the lab, by hand.

Here is the schematic (PDF, EAGLE) and the PCB layout (EAGLE). I program each chip with a unique serial number to prevent COM port build-up. I use the MPROG 3.5 utility from FTDI with these settings.

Originally I was only selling these USB-TTL adapters with the Breadboard Arduino kit, but due to popular demand, I am now selling it separately in my online store. You’re more than welcome, however, to make your own using the files provided above. The entire design is placed by me in the Public Domain. Go nuts.

There have been some USB-TTL failures in the field from the very first batch of 100. These are being investigated to try to improve their reliability. Every disappointing and frustrating failure is an opportunity for improvement. If you are having problems with your USB-TTL adapter, please feel free to contact me to see what might be the matter with it. I expect machines and tools to perform their function without a lot of fuss. I’d also like people to use these little gizmos to build interesting and fascinating things and not have to spend lots of time trouble-shooting the components.

Welcome MAKE Readers!

MAKE vol 25 features a little article I wrote about building a “Breadboard Arduino”.  You can buy a kit that contains all the parts for $40.  Click on the giant “Buy Now” button to order one today!

The kit includes everything you need:  a solderless breadboard, jumper wires, a pre-programmed ATmega328P with pin label, USB adapter and basic components to perform the basic “software experiments” in the article.  You need:  a computer with a spare USB port that can run the free Arduino IDE software and a USB A to mini-B cable.

The first 99 buyers also get the “Li’l Larson LED Scanner Expansion Pack”, for free!  OK, it’s just 5 red LEDs and some more jumper wires but you do get a really nice, custom laser-cut LED bezel for maximum Cylon (or K.I.T.T.) action!

Breadboard Arduino Kit

Breadboard Arduino Kit contains all the parts you need to build a Duemilanove-compatible microcomputer with your bare hands - no tools required!

12V Dimmer Kit V2 Now Available

12V Dimmer Kit V2

12V Dimmer Kit V2

Here it is, finally! The12V Dimmer Kit V2 is now available.  You can buy one in my on-line store for only $14.95.  They are also available from BG Micro in Dallas TX.

What is a 12V Dimmer Kit V2, you ask?  It’s an especially efficient PWM (pulse-width modulation) controller for 12V loads up to 60W.  Use it to variably dim LEDs or control the speed of DC motors.  It comes as a kit and you solder it together.

Have a look at the User Manual and Assembly Instructions (1MB PDF).  I’ve also got a schematic diagram available for your inspection.  The source code for the microcontroller is also freely available, if you’d like to tinker around with its innards, or just take a peek.

The 12V Dimmer Kit V2 is both new and improved.  “How can it be both?” you ask.  I’m glad you asked.  This is a redesign of of my previous 12V Dimmer Kit and includes several improvements in both the hardware and the software.  I’ve also added some completely new features that were not present in the original kit, so that makes it new as well.  See?  Aren’t you glad you asked?

This kit started out as a simple dimmer for one of my IR Spotlights.  A customer in the UK wanted to photograph bats at night and needed a variable infrared source for his camera.  I built two of those dimmers and they worked well for the intended purpose, but I was never really sure how well it would work in other applications.  Another customer showed me a kit he was buying from overseas and I thought I might try making my own.  It worked pretty well at about 25W and sold out every time I built a batch of them.  Unfortunately, I had designed in a component that was once cheap & plentiful in the surplus chain but one day ran dry.  It took a long time to find an adequate replacement that I could count on.  Once I did, I sat down and started designing the new version, hoping to basically duplicate the success of the previous circuit and make a couple of small improvements while I was at it.

Then yet another client wanted a custom version of the dimmer that was operated by a simple push button instead of a dial.  I could get so much work done if it wasn’t for these pesky customers!  (tee hee hee)  The push button version worked well enough, and it made me want to add that as a feature to the existing dimmer kit.  That was kind of tricky!  The upshot is that the new (and improved!) 12V Dimmer Kit V2 will work with either the dial adjustment (a potentiometer) or the push button – or both.

I also wanted to up the power-handling capacity to at least 50W.  I added an extra amplifier stage to the output driver, and was able to get the new kit to handle up to 60W without a heat sink on the output transistor.  It gets a little warm but not much (i.e., you can leave your finger on it).

Thanks to all my beta testers for helping me test the unit in the field, point out obvious bugs and even blow units up.  Your help and attention to detail (and abuse of poor, innocent electronics) has made this a much better product than I could have possibly made by myself.

Let me know what you think in the comments.

More is better, right? 12 LED Cylon scanner Prototype

While waiting for my 12V Dimmer Kit PCBs to arrive, I spent a little time building yet another Cylon-style LED scanner. This time it has 12 LEDs! That’s more than 5! Quick, someone do the math!
Here’s a short video showing how it’s coming along so far. It’s still on a solderless breadboard at this stage. I’m thinking about a PCB that’s about 4 inches long and maybe one inch across, or perhaps slimmer. It should run on two AA batteries.

Let me know what you think in the comments!