View Single Post
  #6   Spotlight this post!  
Unread 10-12-2007, 11:24
Dave Flowerday Dave Flowerday is offline
Software Engineer
VRC #0111 (Wildstang)
Team Role: Engineer
 
Join Date: Feb 2002
Rookie Year: 1995
Location: North Barrington, IL
Posts: 1,366
Dave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond repute
Re: [FTC]: FTC Software Requirements

Quote:
Originally Posted by Richard View Post
Correct operation of autonomous mode is the issue. We saw a few robots with incorrect master code that entered auto mode at the wrong time; i.e., after it was over and the referees were trying to record the auto mode scores. (This happened during morning practice rounds.)
This is off-topic but it's probably a good thing for people to know. Unlike FRC, the Vex field control system does not control autonomous mode. The only thing the field controller does is turn the Vex transmitter on or off. Autonomous operation is handled entirely within the Vex RC. What they've done is set up the Vex RC so that it operates autonomously for the first 20 seconds, and then goes into driver control mode. So, if you're seeing robots go into autonomous mode when they shouldn't, you can be nearly certain that it's a problem with the robot. For instance, I believe if the Vex RC resets for any reason it will re-enter autonomous. Perhaps the robots you saw had low batteries and that was causing their robots to reset?

As I understand it, when the Vex robot is powered on, it waits until it sees a signal from the transmitter (any transmitter that is on the right frequency - the team number is not part of the signal like it is in FRC). Once it sees this signal it will begin autonomous mode, and I think it will continue until the 20 seconds is up (even if the transmitter signal goes away). Because of this, we've seen problems where the Vex robots will take off in autonomous mode even when the team's transmitter is disabled by the control system and the cause ends up being that someone else had a transmitter on the same frequency and that triggered the robot to start moving. Thus it is really important to make sure that teams are not operating wirelessly when they shouldn't be.
Reply With Quote