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Re: The 8.2 (or 8.3) Battery Voltage Bug
We (Team #1825, JCH Robotics) have had this same problem, and let me tell you it absolutely killed our robot. Our design probably wasn't as strong as it could have been, but it was solid--however, starting Thursday and increasing in intensity through Saturday, we kept running into the following errors:
Our two interrupt-driven optical shaft encoders failed to update, causing our encoder-based arm and wrist positioning system to drive to its extremes without ever updating the value from the encoder. Thank goodness we had limit switches that were hardcoded to stop all motor operation, or even the foam-core fiberglass/resin compound that composed our arm would have failed.
Incremented variables designed to serve as timing loops failed, making our autonomous mode a signal failure, since our "release ringer" code was never triggered. Without this error, our autonomous mode would have been one of the most successful at the arena--the robot placed ringers perfectly in position several times (until our camera failed Saturday) but the variable that triggered the arm to release was overridden and never reached the expected value.
The camera, when we fired the robot up on Saturday, locked up entirely, despite the fact that it worked fine Friday and no changes had been made since.
Our OI displayed 8.3 volts consistently.
An "Unknown User Violation" displayed on the dashboard occasionally instead of the voltage readings, with no apparent relation to anything done in the code. All attempts to solve or debug this failed. PLEASE, would it be possible to get more detailed error messages than "You have an error!"?
On tether, the robot would work just fine--though other symptoms such as the 8.3 volt output on the OI were still present--however, when hooked up to the competition interface at the arena, the robot failed miserably, as apparently several variables were overwritten, causing the robot to act as if buttons had been pressed when they weren't.
In testing at home, the robot had appeared to work perfectly in testing, responding excellently to everything we did and placing several ringers even in autonomous. Based on this, we hadn't tried any fixes or patches--why fix what isn't broken? However, when we got to the arena, we started noticing these strange errors. We attempted to fix them, came here looking for help, found several bits of advice, and followed them all, but to no avail--the robot's performance only degraded as time went on.
Fortunately our drive train was still operational, and even though it only had 2 small CIM motors excelled at defensive maneuvers thanks to its traction and center of gravity. This allowed us to get into 8th in the seeding rounds--but by the time the finals matches rolled around, the robot was in such a state that it could barely drive, and its arm was entirely useless.
Fixes we tried:
Updating library files (no success; we were using the latest release)
Updating linker files (made the robot worse if anything; certainly no improvement noted)
Rebuilding the code from scratch (a real pain, and a last-ditch effort to make SOMETHING on the robot work, but we might as well have saved ourselves the effort)
Involving the IFI staff at the location (they were extremely helpful, but nothing they suggested made a difference--which puzzled even them)
Asking other teams for help (the Bomb Squad mentor/programmer and a few others graciously suggested a few fixes, but they were as ineffective as the other methods tried)
...
Attempting to punch the robot (hey, it works on my PC! Unfortunately, the RC was set back in the robot far enough that I couldn't reach it from where I was sitting...)
Even though we're now out for the season, I still want to get this robot working for demonstration purposes. What else can I try?
Last edited by WesleyC : 19-03-2007 at 15:57.
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