Hello,
I'm very new to this kind of technology. My question is, can i use Arduino borad, if I want to control(turn on/off) 66 separate LEDs? And if yes, how many board do I need?
p.s. I have to finish this project by the end of this month, do you think it's possible?
Thanks in advance
Other people should probably chime in, but here's what I know:
Arduino has 13 digital i/o pins... so for 66 LEDs, you'd need 6 Arduino boards. An alternative might be the wiring board, it has a lot more digital IO pins (53) but it does cost more. It sounds like that won't be even enough for what you need, so you could get one of each, and that would be enough. In the USA, sparkfun electronics sells both, and they accept paypal. They're super nice.
Now there's probably a third option, which I'm almost completely unfamiliar with but would love to learn more about, LED drivers. This would be a separate circuit that would handle addressing all those LEDs from a smaller number of I/O pins, in which case possibly one arduino would be enough.
Someone else please add a reply too, I'm no expert :-?
Well, i did some research on my question and found that there are 2 best possibilities;
First, according to this http://www.arduino.cc/en/Tutorial/LEDDriver
1 driver can control 8 separated LEDs, therefore, the solution is combining 1 arduino board with 8 LED drivers to control 64 LEDs, do u think it's possible to delay each LED in 64 of them to turn on/off individually
Second is to use 2 arduino boards to create a 8x8 LED matrix.
In your opinion, which one makes more sense?
Thank you
you need only one board
if you are trying to drive individual LED you can use the circuit in http://www.arduino.cc/en/Tutorial/LEDDriver
and daisy chain multiple circuits... you can (teoretically) drive hundreds of LEDs with that circuit.
if the LEDs are in an 8x8 matrix use the MAX7219 chip. you can find many references to it in the forum
massimo
Thank you very much, stevecooley and massimo. I've ordered all the stuff I need, can't wait to see the result. 
I also trying to run a large number of individually controlled LED's. I need the states to be able to change rapidly and synchronously. I checked out the tutorial with the Philips LED driver but it left me with a few questions. It says you can daisy chain infinitely. But there must be some drop off point where you end up losing sink or you get some delay. Does anyone know at which point it gets noticeable? Does it make sense to devote four pins to one led driver and the next for to another and so on? Is pin13 strong enough to be used as one of the four pins that run an LED driver?
thanks. -John
The project I have in mind is probably similar to the OP and the last poster.
Has anyone hear from Kool since his last post re his project?