It's not space technology, really. Pins are either high or low referenced to ground, which means 1 or 0. There are no intricate communication standards here. You can take a look at http://www.pminmo.com/ as I did. If you're into PIC programming, you will find some good documented controllers there and by any means build one just for the fun of it. I have made my own controller at first, but later bought a 4-axis one.