13 October 2010

The Charlie Cube

Project Features

  • 27 LEDs in a 3x3x3 configuration
  • Controller is a AVR tiny13 with 1 kByte of program memory
  • Programmed in C

The idea is not new. You can find loads and loads of LED cubes on the net. Some are small, some are insanely large and some even use RGB LEDs. And I must say I like them all. One LED-cube caught my eye because it mentions that it uses charlieplexing to control the LEDs. Its size is 5x4x4. But the instructable also says that with the 14 ports used it could have controlled 182 LEDs instead of the 80 it actually uses.

This got me thinking. How would you go about if you wanted to make a charlieplexed LED cube with efficient use of the available ports? Basically, with charlieplexing you get a multiplexed 2D matrix. How do you fit that into a 3D cube? (For the rest of this post I assume that you know what charlieplexing is.)