Neat. I'll have to pull out one of those bags of loose LEDs sitting in a box on the shelf.
Using discrete transistors has some educational value, but, for us lazy oldpharts, a couple of ULN2003s would be easier to wire. Maybe even cheaper, if you don't have the transistors on hand.
Hey systemx, do you know of any darlington arrays that are PNP transistors instead of NPN. You know, I want the base to SINK current and the darlington to turn on when the base is low.
I can find lots of single PNP darlingtons but I'm coming up pretty dry for arrays!
Well I tried to find something on google and I came up short.
Well in the end you can always use regular PNP transistors and if you want to get a low price you can go to ebay and buy like 100 transistors for a dollar(this is what I did ;)).