At Burning Man, I’ve long been entranced by projects with hundreds of pixels, that is, LEDs that can change brightness and color under individual computer control. If you array a lot of these, they can do very, very cool patterns. What if we made a coat that could do the patterns? Of course, it’s been done, and Arren is way, way deeper geek than me. Still, it sounds fun, and I could learn a lot. Here we go.
I met Boz at Noisebridge, and he started me down the path with basic Arduino ideas and some wiring thoughts. I spent a few days thrashing around worrying about how to solder hundreds of tiny LEDs on top of fake fur, but that was a wrong direction. Boz pointed me at LED strands from Adafruit. These have 25 LEDs in a continuous strand. Each pixel has an LED and WS2801 chip, so each pixel on the whole strand can be addressed individually with only two wires (CLK and DATA), plus GND and +5v.
Boz also alerted me that supplying power is going to be a significant problem. Each strand of 25 LEDs will draw approximately 600 mA per LED * 25 = 1.5Ah. That’s a whole lotta power. Thinking starts.
A side note: starting about 11 years ago, I spent quite a while building desktop computers. I built maybe 10 of them for myself and others, buying the CPU, motherboard, memory DIMMs, disks, case, power supply, etc. Then I’d install gnu/linux on them, and enjoy. The point was not so much to get a cheaper computer (they were always more expensive than a comparable Dell). The point was not so much to get a computer that did not have Windows pre-installed, though that was a plus. I did it because it was fun and I liked learning how all the pieces interact. I don’t do it any more because a) I use OSX now and the hardware is utterly unhackable; and b) I use laptops. I still have a giant, ridiculously heavy, power-hungry, and now underpowered machine I use as a linux box when that’s useful.
Anyway, the coat is “for Burning Man” in the same sense that the computers I used to build were “for computing.” Yes, that’s how I’ll use it, but there were much easier paths. The journey is the way, the destination a side effect.