I'm working on making two 8x8 grids of 10mm RGB LEDs to be synced to pulse with music and I've hit a wall in my planning process. I have all the code down for getting a single LED to pulse correctly and everything, but I don't know how I could provide external power to expand the effect to all 128 LEDs since the 5v Arduino won't power all that by itself. How could I go about wiring external power to all 128 LEDs without overriding the PWM audio signal from the Arduino to the LEDs or frying anything?
I'm not trying to wire the LEDs like a matrix, I'm just going to probably use shift registers to extend my number of PWM outputs, separate LEDs into groups, and set them to react to different audio frequency bands from an MSGEQ7 (tedious, yes, but I'm trying to keep the whole system as basic as possible). I've seen tutorials where people use amplified audio signals from old stereos and speakers, could I use something like that?
So far I'm anticipating needing: God knows how many shift registers (or http://www.sparkfun.com/products/10136 if that'll be more suited for what I'm going for) Boatloads of resistors and capacitors (I don't know what kinds or how many, that's one part of what I need to figure out) 128 LEDs (haven't ordered them all yet because I need to figure out what combinations of common anode/cathode LEDs can make the system more efficient)
Here's a really rough diagram that I hope illustrates the basic principle behind what I'm trying to accomplish: http://i.imgur.com/G5QUX.jpg Is there a more efficient way of achieving this?
Any help would be greatly appreciated!