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The ChromoDisk aka ColorMesh v1

... is a round PC board with 9 rings of 18 RGB LEDs each. The microcontroller and other components that make it work are in the center. The design is based upon the [Aurora Instructable]. Since I've worked with AVRs, and this seems like an interesting introduction to PCB design with LEDs, I decided to redo the original to fit into a 100mm dia board for minimum cost. I also designed it for a AA battery pack on the back side of the board. We'll see how long it lasts with 162 LEDs!

Current status: Boards in, first prototype done (5 hours to assemble!), writing software for it. Here's a demo of a simple program I wrote:

Demo of prototype





Notes on Improvements:

  1. Improve power distribution. RESET pull-up is at the end of the line.
  2. Polarity of battery holder is reversed.
  3. Add ground plane.
  4. Pull-up on SCLK line affects programming.
  5. Need to current-limit base drive on Q1-Q9, else overheats CPU.
  6. Add 220uF cap to power supply to avoid programming problems.