Jaguars Do Not Connect to BDC-COMM

[Bryscus]

Originally Posted by dyanoshak

That being said, it is definitely possible for an over current condition to happen so fast that the Jaguar can't fault in time. The current spike can dip the supply voltage so much that the Jaguar browns out and therefore resets.

-David

David,

True dat. In 2010 we had a coupled four wheel swerve drive system, however our modules couldn't continuously rotate, they were limited to about 270 degrees of rotation in each direction. So when the modules reached their rotational limit in one direction, they would quickly spin 180 degrees in the other direction and reverse the wheel rotation. Well, the current spike from hard switching the directions of five Jaguars simultaneously created a voltage dip that caused the Jags to reset (including the position Jag). The open loop Jags (one per wheel) would come back, but the position Jag was dead for the rest of the match (at that time you couldn't change or reset control modes for a Jag).

So we painfully found the limits of the Jags that year (and it was daunting for the longest time). We corrected it by rate limiting the Jag outputs (now this can be done autoMAGICALLY in the current firmware).

NOW, THAT BEING SAID: Most people will not run into this situation. Normally, the Jags are driven by a joystick like input so that even though there is no software rate limiting, there is inherent rate limiting because you can't move the joystick fast enough to go from full out forward to full out reverse.

If anyone DOES happen to run into a similar situation, enable rating limiting.

The things you learn when crap breaks, huh?

- Bryce