Adding watchdogs to track down a halt

The car controller is dropping out now and again for no obvious reason. I thought it was due to the cold changing the internal RC oscillator frequency and making the serial communications unreliable, but I’ve switched to a 12 MHz crystal and it’s no better. The problem doesn’t happen inside, so I suspect it’s interference from the motor causing a serial error which the serial driver locks up on. Restarting the program without resetting the hardware clears the fault so I should be able to handle it in software as well.

I’ve added a watchdog on all of the interesting dimensions: GPS data, GPS lock, input from the remote, heartbeats from the board, and two-way communications via a ping. Hopefully the fault will now show up in the logs.

I’ll dump the message and error counter to the log as well to see if the rates change when driving.

Heh, next thing you know my car will be running Borgmon…