The code is here:
probably needs updating anyway...
The thumbstick control does need some work. The logic for reverse still doesn't match forward. Ultimately I would like it to drive like a wheelchair, with full range of motion plotted to a single stick. (it currently also works with "WASD" and "IJKL" for fast and slow keyboard control)
A wheelchair uses 2 potentiometers crossed so one stick controls forward and reverse for both wheels depending on the range of stick motion. Emulating that was just too time-consuming, but would make driving alot easier, and free up the other stick for future things like camera pan-and-tilt or apendage control.