Arduino is my first ever micro-controller experience, and I must say I see a great amount of potential for projects with this handy little guy. I have messed around with it a little bit now, becoming familiar with writing code and hooking things up. I particularly like what I can do with LEDs. That spawned my first “big project” idea. I would like to use Arduino to control a large number of LEDs. Now I have done a little digging around and found many examples of LED matrices, mainly used to dance to music or scroll a message. What I would like to do is even simpler, but I am not so sure how to do it exactly. I would like the Arduino to control a matrix of 50 or so LEDs at one time. To better elaborate what exactly I mean, I am going to make my own LED tail/brake lights and turn signals. I know you might be asking, “Why not just buy them? They sell stuff like that on eBay.” Hey, where is the fun in that!? I want them to be controlled via the Arduino. Now, I know that there are other forums on here about something similar. I have a design idea in mind as to how I want to program it and all, but the thing that I am getting hung up on is how to power all of those LEDs at once, when the output pin is high. I obviously wont be able to run 56 LEDs off of the Arduino, so I plan to use the 12VDC from the vehicle to power them. I will wire LEDs in series sets of 4 and wire those sets in parallel to distribute my volts/amps evenly. But the question becomes how to I activate the LED module from Arduino? I am assuming a transistor? Or some type of relay?
I have attached a schematic and and pcb layout of what I am referring to. Thanks for all of your help.
EDITED 3/15/13 - Removed Original Schematic Attachments. Will post new in reply. ~Brandon.