Arduino charliplexed heart
Here is an Arduino controlled Charliplexed LED heart just in time for Valentine’s Day. It uses a total of 6 wires to controll the 27 LEDs. A PIC or AVR could easily be used for this, but the designer have Arduinos lying around and they are easy to program.
   Arduino charliplexed heart
See more on Arduino charliplexed heart website
www.instructables.com