The GPS log files

Well the GPS log files confirm that the data coming from the GPS serial port changes no more often than 1 per a second. Looking back though the newly discovered PDF version of the GPS programming manual I see that it expressly states that the GPS computes a position solution only once a second in its performance spec section.

The turn rate and short (90ft) distance I had the bot going won't do with that kind of update rate. If I want the test program to really work I will need to slow the turn rate way down and probably the the overall speed as well.

I'm not sure if I'll bother since I think I understand the issue pretty well and the time might could be better spent coming up with a new dead-reckoning+GPS based program. The motor controllers are all wired to do closed loop control on the motor velocity. I just have to set the jumper and write a program to set a new heading based on a timed difference in left/right wheel velocity. I could even double check the new expected heading with the GPS.