[RyanN]

I've been messing around with things today and yesterday trying to break the robot.

Power and brownouts should be a non-issue. If the teams use the OEM cable, the connection remains consistent and has no drop outs.

We also were running with a dead battery. The first thing to give out was the digital sidecar. It resulted in the robot quickly flashing our LEDs on and off as it would brown out the DS,.causing the relays to turn on and off rapidly. The voltage went down to about 4V before I shut off the light show. The cRIO (4-slot) and the Dlink remained powered and connected the whole time with no dropouts.

We have also been testing CAN out a bit, and found some unsettling results.

If you have an intermittent connection where a CAN devices does not appear on the CAN network, the whole CAN network will drop out, and the digital side car will not work. The thing is that the robot remains connected the entire time.

This was not the cause of our problem as we went back to PWM during Bayou, but I can see teams complaining about no communication due to this.

We originally had 4 CAN-enabled Jaguars, IDs 2, 3, 4, and 5. ID 5 was the last in the chain, and had the terminator resistor installed. We wanted to test 8 Jaguars over the RS-232 to see how well it worked. Well, we assigned IDs 6, 7, 8, and 9 to the drive motors. When we plugged it all back in, nothing worked. We found out that when we extended the network, that the Jaguar with ID 5 had a bad RJ-45 port. To work temporarily, we rearranged the cables to make that Jaguar the last in line, and it all worked again.

So that's another idea that I had as far as troubleshooting.

We can't use the 8 jags though... I'm not sure if we reached the limit of RS-232 driving CAN, but we were getting tons of CAN timeouts, and Drive Motors not being called fast enough warning (in teleop). I analyzed the timing of Telop, and found that it ran every 10ms on average, but 60ms to 500ms spikes were not uncommon (where we saw the timeouts). When this occurred, we would also glitch/jerk.

I think it has to deal with calling CAN devices at different times. We have Periodic Tasks running a shooter control loop every 50ms, and then Teleop is called every 50ms. I think there is a resource conflict and timing issues and we occasionally get a bus lockup for a split second. Going back to PWM, we run at a constant of 3 to 4ms to run the Telop task.