Whee, Jaguar problems!
So here’s the gist of it: We have 2 Jaguars on CAN* (interfacing via serial) to control our two shooter motors. The problem is that after we throw our robot into action** - driving, acquiring, conveying, shooting, bridge tipping, the whole nine yards - we find that our top shooter motor tends to cut out (we had both shooter motors cut out towards the end, not long before we bagged). After they’ve cut out, the Jaguar LED stays a solid yellow; any further signals we send to it elicit no response. When they cut out, though, we’ve seen a number of patterns. I personally observed slow flashing yellow and slow flashing red, the latter which makes sense to me given our massive voltage dips, but I can’t make heads or tails of the former. Teammates have also mentioned seeing slow flashing red or yellow***. The Jaguars settle back to a solid yellow as soon as we stop moving the robot.
*We’re using serial to interface and setPID() to tune the shooter wheels. Our team uses Java. These are the only Jaguars on our robot; we use Victors to control everything else.
**We’ve found by monitoring battery voltage that this kind of activity easily incurs voltage dips to 6V, and on one occasion, 4V. We know the mechanical issues associated with this problem (overtensioned 8WD with pneumatic wheels - although interestingly, the fuses don’t trip when we try to turn in place; turning seems to stall the CIMs), but are still worried that fixing this problem may not be enough to fix the problem at hand.
***This was one incident, and he wasn’t entirely positive if that was the color pattern we were seeing.
We’ve found that a hard reboot (opening and closing the central breaker) as well as a soft reboot (rebooting the cRIO from the DS) both fix the issue. Pulling and restoring the corresponding fuse on the PDB (to power cycle the Jaguar, and only the Jaguar) does not rectify the issue (we didn’t check whether or not it can cause the issue), which is what led me to suspect that its configuration is what’s being reset.
Switching motor leads on the Jaguars (that is, whereas Jaguar 1 & 2 are connected to shooter motors 1 & 2, we tested Jaguars 1 & 2 on motors 2 & 1) found that the issue lay with our upper shooter motor in particular, but towards the end, we managed to reproduce the issue in both shooter motors, so I think that’s attributable to manufacturing tolerances (and that we somehow managed to increase the current draw of our drivetrain).
I suspect that the problem we’re having is that our voltage dips are power cycling the Jaguars, which in turn resets their configuration and is what makes them unresponsive. The responses to this thread in particular helped me to arrive at this conclusion.
Is my conclusion correct?
If so (and even if it isn’t, because I’d like to know), what effect will power cycling a Jaguar have on its configuration?
If not, what do you think the problem is?