Joystick Connection Issues

[Pratik Kunapuli]

Originally Posted by markgryzwa

Randomly, in two regional events and one week zero event, we've lost the joystick connection during a match on the field. On a few occasions it recovered. On other occasions we never got back the joystick during the contest.

We can run for hours in practice without ever losing the joystick on cable or wireless. It's a little peculiar as we don't lose robot code nor communication.

Anyone run into similar issues and have success debugging/fixing?

Thanks, Team3206 Royal-T-Wrecks

We had a very similar problem at FLR. As we were setting up the driver station before a match, one of our two gamepads did not show up in the setup tab. We unplugged it, plugged it back in, and clicked F1 (to re-scan for HID's), but nothing worked. What we found is that it was the gamepad itself that was not working and we replaced it.

When a joystick or a gamepad does not seem to be responding, my first reaction is to spam the F1 key while unplugging and re-plugging the device. It's safe to say that I will always keep an extra gamepad with me from now on.

[Mark McLeod]

1. Keep your laptop plugged in at all times while on the field.
2. Change your USB device settings to disallow Windows from cutting power to the USB ports to save power when the laptop is not plugged in.
3. Test your controllers every match after you've connected to the field (look for the Setup tab blue when pushing a controller button).
4. Don't let your laptop go to sleep or hibernate. The USB power gets re-negotiated when Windows wakes up.

Warning: power hungry controllers may brown out during competition. Basic controllers (no fancy lights) connected directly to the laptop USB ports (not hubs) are safest. When the driver station laptop battery gets low it begins to cut power to USB ports starting with the ports with the highest power drain. Usually, that means starting with ports connected to bigger drain USB hubs that have several devices hanging off them.
Changing Windows USB Power Settings

[Jared]

We also experienced a weird issue like this today. In autonomous, our robot worked fine. Once we got to teleop, two of our three joysticks stopped responding, and when I went to the driver station setup tab, the driver station stopped responding, which I've never seen before. The driver station came back after around ten seconds, and I pushed F1, and the joysticks came back.

It's worth noting that this problem only happened to us on the field, and did happen after the laptop was woken from sleep mode, but that we ran about half our matches with the laptop just waking from sleep. The laptop was plugged in, the USB power save mode was off, and the joystick names turned blue when a button was pushed about 20 seconds before the match began.

Another team seemed to experience the same exact issue, where they had communication with the field and were enabled, but their joysticks didn't work for the first 20 seconds. It's probably just a USB driver issue.

[bkahl]

F1 is the driver's best friend.

[Greg McKaskle]

I have seen it with other teams. Sometimes it is clearly the gamepad connector or cable. Other times it seems to be the laptop ports as gamepads fail there and not in other ports. Clearly you should avoid physical shock to cables and connectors. They can bend, they can break.

I have not confirmed, but some claim that static electricity can cause a joystick to drop out. So perhaps those fuzzy slippers aren't an ideal part of an FRC uniform.

Finally, modern laptops don't like to give their power to other devices. USB devices ask and the laptop giveth ... or not. Personally, I'd plug in the laptop, or make sure that your testing is also battery powered.

Greg McKaskle