Robot Locking Up... RSL is on solid

Hello everyone.

Last evening as we were working on the bot getting ready to bag it up, we had a recurring issue with the robot controls completely locking up; no joystick control, no nothing. We can disable and re-enable from the drivers station, but nothing happens. We also noted that when this happened that the Robot Safety Light (RSL) went on solid (no flashing).

We then noticed that when we did get it running and tried to use our autonomous routines, that none of the digital sidecar sensors were reacting (we could see the line sensors operation lights change, but nothing back at the drivers station).

We are running CAN and swapped out many batteries and made sure we had good voltage throughout the system. Upon startup all sidecar and PD lights were on and green.

We have updated all firmware to the latest version as requested by FIRST.

Does anyone have any ideas? We are going to have to try and fix this at regionals (of course) and we would like to have a plan of what to check/replace by then.


Floyd Moore
Mentor FIRST Team 997

A solid RSL usually indicates the robot is in autonomous mode.
Was it also solid in other modes set by the Driver Station?
Any Diagnostic messages on the Driver Station?

I’d test with the generic default program to isolate the problem to electrical vs. programming.
If the default code exhibits the same problem, then concentrate on testing the electrical side.

If electrical in nature then it certainly could be a Digital Sidecar acting up. You can swap out components and move modules to help isolate it, using the status LEDs on most components.

If programming, then you can work backwards through the code, or restore a previously working version and work forward through later changes.