LED PWM Lighting Module
Finally got my box from Mouser, and started building up a prototype lighting module for this project. You can see a picture of the module in the first photo. It's basically 12 super-bright LEDs (4 red, 4 green, 4 blue) arranged in a circle, with a ULN2003A, ballast resistors, and a six-pin header for connecting to the main board. I'm not planning to show you the bottom, as it was my first real soldering attempt and it ain't pretty. :) I still have to write some code to allow me to communicate with this thing via RS-232 so I can change the color settings on the fly - so I haven't really tested its color range at all. But I am finding that the colors don't blend particularly well (although it's hard to tell, because the only color I've tried so far is 'white' - i.e., all LEDs on at full intensity). I've seen other projects on the web that do this kind of blending, and most of them don't seem to be having this problem. I'm not sure, but I suspect it may be because these particular LEDs have a pretty narrow viewing angle, so the light doesn't really spread out much, which is limiting the blending. Hmmm.... will have to do some experimenting soon. The last picture is with all LEDs at full intensity, but it's a little misleading. The colors don't actually blend as well as it looks like in the photo.