Jaguar Speed Control Issues

[Kovs]

Hello, I'm a programmer for my team, and we're having problems getting the Jaguars to work in Speed Control Mode (PercentVBus works fine, jaguars return their speed).

We're using quadEncoders on toughboxes. I've tried many combinations of different P's, I's, and D's.

With positive P's, the drive usually won't do anything until the wheels are moved while the wheels are supposed to go in one direction. In this case the jaguars go to full power.

With negative P's, the drive usually jitters back and forth rapidly whenever I give it input (1.0). Could this be oscillation around a low speed?

I have to wait until exams are over on Thursday to try code on the robot again, but I want to check to see if perhaps these are signs of me skipping over something. Or maybe I should just be trying a very small negative P?

I appreciate any replies.