We are having troubles with our VersaPlanetary Integrated Mag Encoder that have us stumped. The VersaPlanetary gearbox stages are mounted to the output shaft of our elevator gearbox. One of the stages contains the CTRE Mag Encoder. The output of the encoder is connected via ribbon cable to a Talon SRX.
The problem is that when the elevator is driven hard (quick starts/stops) the encoder appears to slip causing our preset encoder targets to be lower than expected. If the elevator is driven at a lower speed/acceleration the encoder works perfectly.
We duplicated this behavior on two robots with two different encoders.
Each slip is about ~400 ticks which is ~1/10 of a rotation or 36 degrees. This is ~1/4 inch of elevator travel.
The slippage will build over time until the elevator is inches off its expected height. It only seems to slip in one direction.
Our software uses the encoder is in relative mode.
We dashboarded the pwm counts along with the quad counts using getSensorCollection().getPulseWidthPosition() and found that the pwm and quad counts moved in lock step.
The Talon has firmware version 4.22 and hardware version 1.7.
We are working around the problem by resetting the encoder when the elevator is down on our bottom limit switch.
Any help would be appreciated.