retrolefty:
base wired to suitable series resistor (200-1,000 ohms), other side of resistor wired to arduino output pinLefty
Sorry I don't mean to hijack your thread, but this question seems relevant to the topic;
How do you choose a resistor value for this application? I have been using N-channel MOSFET for low-side drivers. Example here:
http://www.ladyada.net/products/rgbledstrip/#usage
But they are kind of expensive. I have lots of cheap 2N2222 transistors that I could use for lower current projects, but I'm not sure how to choose the resistor on the base.