We have motion!

Currently using a linux box with the Devantech USB-I2C (I think I may have exhausted the almost infinite patience of the bplan QNX support guy :) ) I've gotten communications working with the four SRF02 sonars and the MD23 motor controller.

The sonar comm was pretty straightforward, just reset all the I2C addresses to get multiple sonars on the bus.

The MD23 gave me some fits (if you're interested in the details, see
USB-I2C - what's special about register 10?), since I tried to do a little demo program to read the battery voltage and ended up learning the protocol, timing, and hardware for I2C! Anyway, I've now got temporary cabling between the MD23 and my motor/encoder (the real connectors are on order), but I can command velocity, read encoder counts, etc.