Rocky Mountain College * Department of Computer Science * 406 208 3193 * turn on javascript to see my email


In the last several years I've become a far of robotics, microcontrollers and in particular the Arduino microcontrollers. Here are a few recent projects:

Blinky lights badge

I've wanted to try and use the Arduino-family of products to try and get middle-school students interested in computers. While I've seen a number of "blinky lights badge" kits at different places, the goal of this project was to 1) design something that could be programmed like an Arduino, 2) could be made from scratch so that at the end of the project the student could walk away with something in their hands that they made and worked, 3) had a much lower cost than the kits I've seen online.

Read more here...

iPhone-based Garage Door Opener

We have a very old garage door opener in our house, and it only has one remote control, and is too old to use a "universal" garage door opener. I wanted to try and make two new ways to open the door. The first was a keypad so my son could open the door from the front. The second was a method to open the door using our iPhones.

Read more here...

Low-Budget Arduinos

While the Arduino and its various shields are far cheaper than larger robotics systems, costs can still add up. The first project has been using the attiny systems as an alternative to the full-blown Arduino system. We've worked with the attiny85, a simple 8 pin version of the chip in the standard Arduino controller. With those 8 pins, you get 5 different i/o channels, either digital or analog. While that is not enough for complicated systems, it is enough for something simple like a keypad. And at a single unit cost of around $2, that opens up many more projects to microcontroller.

I've also looked at alternatives to the ArduMotor shield or the DFRobot Romeo Arduino w/ integrated motor controllers. While both are great products, they are expensive, especially when compared with the cost of an attiny85. We have built alternative motor controllers using the ULN2004 7-channel NPN darlington array. Essentially the ULN2004 is just seven NOT gates, but they have high power outputs. Each channel can sink 500ma at up to 50V, and the chip is designed so that multiple channels can be directly tied together without any additional circuitry. So each ULN2004 is capable of driving 3.5A. Best of all, the ULN2004s are available at a cost of $3.20 for 5 chips through EBay.

You know we're constantly taking. We don't make most of the food we eat, we don't grow it, anyway. We wear clothes other people make, we speak a language other people developed, we use a mathematics other people evolved and spent their lives building. I mean we're constantly taking things. It's a wonderful ecstatic feeling to create something and put it into the pool of human experience and knowledge. -- Steve Jobs, Rolling Stone, November 1983.