V5 Controller disconnects


#22

I had disconnects happen during every match during states,

It happened during the transition between disabled and enabled, as well as during the match, but I’d say it was more common during the transition.

It was programmed using VCS

I was displaying text on the controller LCD.

The screen went red. We had to restart the controller to get robot functionality back.

The battery was fully charged.

I cant say i noticed a color change.

We couldn’t get it to happen running just the controller, however it happened when using the competition port on the controller. I’m going to try using the controller and just a cat 6 wire later today, without the cat 6 plugged into anything.

Edit: I forgot to mention that sometimes after reconnecting, the joysticks refused to control the drive, we would then exit the program, re-select it and the robot would run just fine.


#23

My team competed this weekend at the WPI event. Prior to this I believe we had one competition disconnection. We occasionally see them in practice, however they are almost never during actual usage (typically when the robot is being handled, or cables plugged in etc.) and there is almost always noticeable ESD. At the WPI event the first day was Skills only and we had 3 disconnects in our first two attempts. The first run was driver (two disconnects about 15 and 45 seconds in) the second was programming (about 15 seconds in). Every disconnect was immediately proceeded by contact with the perimeter. After the third disconnect, we removed and reattached the wireless sensor with plastic screws and made sure to release any built up ESD before starting subsequent runs. I believe the drive team was causing a charge to build up carrying the robot to the field. I didn’t see any other teams having similar issues and I think it is partially due to us not being acclimated to the cold/dry climate. We had no additional disconnection issues through the subsequent 13 matches (5 played on the same field where the prior disconnections had occurred).


#24

We have certainly had disconnects in the lab too, but there could have been one more V5 robot powered at that time. Not tens of robots as in a tournament, but I am still not sure if it ever happened with NO V5 in the vicinity.


#25

@reflxshn and all - what is the best practice to release the built up ESD ?


#26

There are some additional suggestions from VEX for limiting ESD beyond spraying Staticide on the field: https://help.vex.com/article/148-vrc-team-esd-notice

  1. When driving on unprotected surfaces, you can apply static guard directly to your robot wheels and allow the moisture to evaporate. Use Heavy Duty Staticide or the Staticide Wipes made by ACL Inc. As always, please follow the manufacturer’s recommended instructions for use and safety precautions.
  2. Do not allow any cables on your robot to drag on the ground. Keep cable lengths as short as possible.
  3. Be aware of ESD around you and take precautions. Understand that static buildup is caused by friction between non-conductive parts, like sliding your shoes on carpet, or wheels rolling on a field. When possible avoid static buildup.
  4. Discharge static from your body prior to working on your robot by touching something conductive and grounded, like a power strip or wall outlet screw.
  5. Discharge static from your robot by touching your robots’ metal frame to the metal field perimeter prior to placing the robot on the tiles.

#27

We had the driver hold the perimeter and touch a piece of steel (like a key) to the frame of the robot after setting it in the field.


#28

I figured I would chime in with our situation to offer more information to go off of.

When we disconnect, it is typically for about 1-2 seconds with the controller suddenly going red and then coming back quickly. For the short time period that it does disconnect, everything stops moving. This happens to us at random times during driver practice or during a match, not specifically between auto and op control or anything else. Our robot is programmed with PROS. We do display a small string on the screen occasionally.

Both the robot and controller battery are usually well-charged when this happens. I’m not sure what color the LED on the radio is though since happens for only a short time. So far this hasn’t been too common for us, but when it does happen this is usually the situation.
Thank you!