Thread: Robot Power Issues
View Single Post
  #2   Spotlight this post!  
Unread 06-04-2011, 10:17
Jared Russell's Avatar
Jared Russell Jared Russell is offline
Taking a year (mostly) off
FRC #0254 (The Cheesy Poofs), FRC #0341 (Miss Daisy)
Team Role: Engineer
  
Join Date: Nov 2002
Rookie Year: 2001
Location: San Francisco, CA
Posts: 3,082
Jared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond repute
Re: Robot Power Issues
How many motors (and what kind) are on your bot? In Florida, we were running 4 CIMs, 1 FP, 3 RS-775s (that developed case shorts, providing low resistance paths between the battery leads), and the compressor, and at times we browned out the cRIO when everything was running at/near stall at once. The heavy current draw is even worse when you have poor or loose connections in the current path and/or BaneBots motor case shorts (adding to the resistance and therefore voltage drop).

Perhaps try watching your battery voltage if/when you can reproduce the problem. Plotting the battery voltage (with LabView or a Dashboard program) is even better. If you see it dropping (even momentarily) south of 5 volts, you risk causing a cRIO power cycle (the PD board requires ~4.5 volts to maintain nominal voltage to the cRIO).