As a followup, I've finished schematic and board layout, and it looks pretty fantastic. The version I now have in hand has:
- Xbee/RN-XV header.
- USB for programming and communication.
- DMX input and output.
- 425 lumen RGB+white LED.
- Onboard microphone and audio analysis chip that sends 7 band DC amplitudes for each frequency bin.
- All SMT components so that the entire back can be rigidly attached to an aluminum plate for heat sinking.
- 4.3" x 2.5" footprint (conveniently chosen to fit in the smallest of my favorite LMB Heeger Case - http://www.lmbheeger.com/products.asp?catid=68
- Automatic switchover power to allow programming over USB (as long as the LEDs are not activated since they'll blow the USB port...)
I'm really getting excited about this one. I had to toss out the shield connectors because of the footprint and routing difficulty, so I might try to put at least a subset of those header elsewhere, but even without a shield you can do all sorts of cool stuff. You could turn it into a USB->DMX converter and light to control a bunch of other lights from a single computer. You can make them all wifi and control them with OSC like I did in a previous project. You can program them to do complex analysis on 7 frequency band intensity information for incoming on-board collected sound. You could have it use that sound to send wifi data to a computer for analysis, and then use the computer to send data back to tell the board what to do. Or use the microphone and wifi to send data to a computer which uses it to do other visualizations along with the LEDs. There seem to be so many cool possibilities!
Best of all, I think I can make them for around $150 in small quantities, and as little as $75 in large runs! Totally worth it for me, although I guess time will tell if other people want them!
Very excited :-D
Attached preliminary board layout and schematic pdf files.