Nothing means more to someone then a gift that took more time to make than money to buy. This is an example of such a gift. Set your way-back-when machines to 2002. Getting ready to finish high school, I had built up some hacker level of electronic knowledge. My parents; both nautical people; have a large lighthouse fountain in their backyard. My mother’s only wish for Christmas that year was for me to build something that would illuminate the lighthouse as if it were a functioning beacon. I obliged, with a circuit consisting of a 555 timer and a 4017 decade counter.  It resulted in a simple device that did the job.

The Kill A Watt is an awesome product; it measures volts, amps and power factor of an individual appliance which can be used to calculate power, cost to run, etc. It’s also quite hackable. But I wanted something that would give me the same data for my whole apartment. After some Googling, the best I could find was this project from picobay, but I didn’t want to invest in an expensive network IO platform. There were also some off-the-shelf solutions, but they too were expensive and limited. Well, time to design my own solution then.

It’s the time again and I bring you an update to my ever aging ‘Mad Scientist’ Halloween costume. What started out as a college budget built led labcoat with just a clock and 4017 decade counter has evolved to include now two Arduino micro controllers. One runs the individual LED rows you see running random patterns. The second runs the scrolling marquee hanging off my chest. Everything is run off a 14.4V Li-Ion battery pack that I custom built.  Even the LED Marquee is custom built.

I’ve set out designing what I’d like to call ShiftTrix, a Arduino powered Marquee. The idea is this, low cost LED matrix driver boards that are easy to work with at (hopefully) around $10 a board including the LED matrix itself.  A similar serial driven LED matrix can go for $35 per 8×8 matrix. That can add up fast if you want to chain more then one together for a large display. Instead, my design is 1/3 the price, and can easily be chained together to create larger displays.

Here is a video of the LED Lab Coat with the better PWM code. If you are interested in how I programed 8 channels of software PWM, here is the source available for download.

A bad video of the new Lab Coat. I rewrote the PWM code after this and the fades are more smooth. Better video coming soon.