This is a 4x8 LED array that should work for this project. The PCB is laid out so that I can choose to either go the traditional passive (simple) route or I can drop a couple of 16 bit LED controllers (TLC5940) that listen to the serial interface and have a 12-bit PWM output so I can control the level of light and depending on the LED selection I can also control the wavelength of that light through LED selection. What I have here is a preliminary PCB, there are some interesting drawbacks to using the the TLC5940. One I read about is if the LEDs have power but not your TLC5940, you run the risk of frying your TLC5940. I found this link (http://effluviaofascatteredmind.blogspot.com/2012/05/tlc5940-tlc5941-and-arduino.html) a wee bit late in my initial development of this PCB, but after I get my PCBs back from the PCB house I will do some testing slap some necessary blue wire down and then add some updates to the PCBs.

I think I will modify the overall size as well to exploit the max size the PCB house is willing to fabricate.