led - How many individual lights can an arduino control

I want to use a regular Arduino board to control LEDs - what is the most lights I can control individually from the board?

Is there a tutorial on how to hook it up?

Answer

I believe using Charlie-plexing N lines controls N*(N-1) LEDs. There is a good article on Wikipedia.

A friend of mine, Jimmie P. Rodgers, fit 126 LEDs on an Arduino Shield. He uses charlie-plexing to control the LEDs. Some information on his board is at -- jimmieprodgers.com/2009/12/my-development-process/ (archive.org copy)

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At the last Boston Arduino User Group meeting Jimmie P. Rodgers drew a Charlie-plexing diagram as a matrix with labeled nets. Schematics drawn in this manner seemed to do a good job of communicating the concept. I created a couple of similar schematics -- See http://wiblocks.luciani.org/FAQ/faq-charlie-plex.html