View Single Post
  #9   Spotlight this post!  
Unread 03-01-2013, 15:22
Brian Selle's Avatar
Brian Selle Brian Selle is offline
Mentor
FRC #3310 (Black Hawk Robotics)
Team Role: Engineer
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Texas
Posts: 166
Brian Selle has a spectacular aura aboutBrian Selle has a spectacular aura aboutBrian Selle has a spectacular aura about
Re: Digital Side Car Issue with Encoder

Quote:
Originally Posted by EricVanWyk View Post
My guess is a chassis isolation fault is affecting one of the encoder channels. Something down stream of an actuator controller (Jaguar, Victor, Talon, Spike, Solenoid Breakout, etc) is asserting a voltage on the chassis (hopefully the battery return voltage).

The value "chatter" tells us two things: The software is fine, since things are moving, and one pin is stuck in one position (high or low).
I unplugged everything (4 talon + compressor relay PWMs) from the DSC except the encoder and removed the circuit breakers for everything except the cRio and DSC. Same problem.

I then tried different combinations of pins for channels A/B and found that pins 2, 3, 4 work when the DS is disabled but not when enabled. If I have one good pin and one bad, I get the "chatter" as you described, two bad pins = nothing, two good pins it works fine disabled and enabled.

Last edited by Brian Selle : 03-01-2013 at 15:26. Reason: more info