Field Disconnects

Hello Everyone,

Over the past couple weeks there have reports of field disconnects often related to the new V5 Brain Field Controllers, we have seen varying reports with various variables and aren’t able to determine anything specific. There are however rumors that say that these issues are related to PROS, this is not the case as field connection is handled via vexos. We have also talked to James Pearman about the issue, with his take being that “using PROS or not shouldn’t matter”. If you do have some concrete proof of what is causing these field disconnect issues (no matter which platform it is), we’d greatly appreciate a detailed report.



As an EP, been working with V5 Brain field control all season. It is the way to go. Have there been glitches and learning curve? you bet! What is nice about using V5 Field Control is looking for patterns in the V5 Brain Event Log (pro tip - check your Event Logs!), such as all four teams getting a radio disconnect at same time - hmmm that Spy Balloon? maybe, now that it is shot down we should be ok:) … Individual team having 5000 cable disconnects -probably cable fault (Hey middle school kids, quit walking off with our driver cables!). So lots of could be source of issues, but never crossed my mind, ever that it is your programming environment.

There are definitely some weird situations - for example, what we call “code yellow” meaning team connected, running program and display says “Wrong Controller firmware 71”, I tell TM operator let it roll, robot does autonomous and driver correctly under field control. We log it at the station as “Code Yellow - team 44” and just move on. Similarly when we see a RED “Legacy controller” (or something like that) we figured out move the control cable to another port and it works - after match concludes, just power cycle the v5 brain and all is usually good for the day.

This last weekend, flawless first day, second day had cable problems (of our own creation) and a skills field zoning out. The skills field was a bizarre situation in which a set screw dropped into the skills V5 brain port and would bounce around shorting out something - funny thing is the screw would not fall out as there are magnets in the V5 Brain to keep the cover on… The things you discover that no one anticipated.

It is weird that now we have more data logged, team are skeptical the V5 Brain Field Control is at fault? I think more data is great - helps me debug issues quicker. I’ve worked with a team with concerns, they now understand the system better, as we do, and can focus on their matches and not worry about control system at the field as much.

Teams will need to learn more about how the field control works and how to interpret the Field Control Application debugging and logging information as this is what teams will be connecting to at Worlds:

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Go find my thread about static electricity.

In short… I’d spray the tiles and maybe go so far as to ground the metal field perimeter.

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Just to add to this. We also had disconnect issues at 2 events skills driver and auton. Not running PROS. We went back to one venue to try to duplicate the issue with no change to the robot and using same field control and could not duplicate duplicate issue. We did competition on 2/6 and were able to run only one driver skills since line were too big (all the time) to do more. That one run was with no issues. So still bit of mister but team now knows how to trouble shoot if issues comes up.

Definitely the long skills line was due to one field brain having set screw jiggle around in one of the ports. Once identified, skills runs ran…

For Regionals we will have more skills fields in place.

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A bit of topics, but let say there is 20 teams and 10 of them are interested in doing skills 3 driving, 3 auton , Let say it takes 1 min to run and 1 to score and 1 min to set up so about 3 min total. (1063)/60 that is about 3 hours of field being available to give full opportunity for 10 team. Is there a specification from vex how many skills fields per let say 10 teams participating.

This needs to be posted in the forum’s EP Black Arts section :slight_smile: You can compute an ideal # skills fields, but end of the day, kids are unpredictable humans. Getting teams to spread out to do skills runs is really difficult to do. We’ve tried lots of different schemes. Our latest is using V5 Brain Field Control - we have a couple that when we see a line get too long, we swap a practice field to skills to do load balancing. My understanding is the set screw problem on one of the controllers threw the whole scheme out the window. End of the day, if you have flexibility of adapting to skills load you can manage it pretty well. At regionals swapping practice to skills worked well.


Our coach recommended us not to use PROS, but I think there is an underlying variable here, one being higher level of programming ability/more initialization at the start of driver. During a disconnect, it restarts the driver control function. We had a gif on our brain screen at our last tournament, so when all of the robots briefly disconnected from the field (this was a problem the whole day) it would disportionately effect us. When it was restarted, it tried to print another gif, but the previous one was loaded, so it locked up the program.