ive been looking around the web and it looks like i can use the ucn5821 to drive the little stepper motor i have. im just trying to figure out how to interface it with the arduino threw serial. whats the full part # for the 595 so i can look up some info about it. when you say it sink current, you mean i would provide voltage straight to a led anode and the chip would connect it to ground to complete the circuit? Seems an odd way to do it, i guess that would mean it could not take much in the way or current?