I spent the day today hacking on an RS485 circuit for the RepRap Project. It was successful, and pretty fun to boot. I managed to send serial data over a big long wire and had no noise problems. This stuff is going to form the basis of the 3rd generation electronics for controlling RepRap machines, and having a noise immune communications system. when you have motors and long wire drops is a major benefit.
Anyway, I wrote up a big long article about it on the RepRap blog if you’re interested in more technical details. Next up: SD Card reading and writing.