We have several Black and gray jags that we’ve been using over CAN for a few weeks during build season. All of them are loaded with v89 firmware. Each Jag has its own non-default (not 1) CAN id assigned using bdc-comm.
We decided during competition to move one of our Black jags back to PWM by removing all connections from the CAN ports and making appropriate adjustments to the other CAN-connected Jags to properly terminate their CAN bus, etc, then hooking up a PWM cable to the Jag and digital sidecar.
We changed our user program to use the PWM-based Jag driver with appropriate PWM port number.
However, the PWM Jag does not seem to want to respond to PWM commands at all. It does get a valid pwm signal as the Jag LED goes to solid orange, but no matter what PWM value we send, it sits at neutral.
Plugging the same PWM line into a gray Jag we’d never used for CAN and never updated firmware on results in normal, expected operation so we do know that our user program is driving the PWM signal properly for non-neutral operation.
Unfortunately, as competitions go a lot of time for debugging was not available. We went back to CAN, changed the code, and everything was fine.
Looking for some feedback from other teams here:
Is anyone using a v89 Jag successfully with PWM connection?
If so, have you ever used that Jag with CAN prior?
I know some of the TI guys are lurking – does the firmware require any settings changed to go back to PWM? Particularly, does it require resetting the id back to 1 or anything along those lines?
I loaded a Black Jaguar with v89 then switched back to PWM later without any issues or having to do anything to the Black Jaguar.
Thanks for the info. Had you ever changed that Jag from its default CAN id of 1?
Anyone else go from CAN back to PWM with success?
I have one Black Jag (v89) that I was switching back and forth from CAN to pwm constantly. It was mounted on our robot (now in FedEx hands), and they were driving with it via PWM. I then drove just the device powered by the Jag via CAN for testing purposes.
CAN address 8.
We switched to CAN and back with few problems. Now the status light on the Jaguars sometimes flashes on the black jaguars when it is a neutral signal, despite having a good pwm signal and working.
Did you check to see if, in the bdc-com terminal, you disabled heart beat?
I will check this – sounds plausible. I didn’t know that heart beat was a (persistently) configurable option.
Thanks to everyone for posting that they’ve done this with success; we’ll go back and re-examine what is happening.
To close this out -we discovered that our problem was with Jaguars that actually had an older firmware (v85!). Apparently that version was not pwm friendly at all. Upgrading the firmware resolved the issue.
Sorry for the misguided report - this was on our 2009 robot, and my understanding that all the Jags had been updated to v89 was incorrect.
Thanks to everyone who confirmed things working as intended.
I didn’t know that heart beat was a (persistently) configurable option.
BTW – Before noticing the firmware downrev, I tried toggling this option. It only seems to modify if heartbeat is send over CAN by bdc-comm at that present time. It does not seem to be a persistent option that modifies Jaguar operation.