Use of a PIC

[HenrikOlsson]

Hi Edwardo,

My question how do I drive all the leds on using a PIC and supply enough current to light them fully?

You don't.... what you need to look into is called multiplexing and is basicly how all LED-signs work. From your alarm clock radio to the huge displays at Times Square. Let's take the alarm clock as an example. Basicly the LED's are arranged in groups, you then set the pattern for that particular group and then turn them on. After a short amount of time you turn that group of LED's on and turn on the next group. If this is done quick enough the human eye/brain will not be able to see that they are actually flashing. In order to keep the brightness of LED's up the current thru them is usually many times higher than the maximum continious current for the very short period they are actually on.

With that being said 1200-1500 LEDs are a LOT of LEDs....Not that it can't be done with a PIC but I'm not sure it's a very good beginners project. Instead I sugest you get 1 LED to turn on and off at your command, then move up to 8 leds connected to portB (for example). When you have that working you can rig a 8*8 matrix and see if you can that going. From there the you could possibly move on and rig a 4*4 matrix of 8*8 matrixes to get 1024 LEDs.

Another tricky thing to keep in mind is how to store/retrieve/output the pattern that you want to display.

Here's a link showing how it's done (not with a PIC but anyway):
http://www.fpga4fun.com/Opto5.html

Welcome to the forum!

/Henrik Olsson.