One fine morning, Jimmie Rogers woke up and decided to figure out how many Charlieplexed LEDs would fit on an Arduino shield. After five hours and some hardcore design and layout action, he determined that the answer is 126. It’s a pretty complex looking board, however he has excellent explanations of the design process and subsequent software development on his blog. The board is a work in progress, but it’s looking great so far!
In the Maker Shed: