[FTC]: Modern Robotics Module Communication Issues

Other FIRST Tech Challenge
1

I mentor 9 FTC teams in my school, and am continuing to have an issue I’m having a hard time finding a fix for. So here is my testing and results.

When I connect the phone to some power distributions I have an issue of nothing showing up in the app. I power cycle, have everything plugged in and off, and then turn on the power distribution. The app does not launch, nor does it prompt me to launch. I use different cables, and try a few more power cycles to no avail. I then take the phone, unchanged and plus it in to the power distribution of another teams robot. I turn on the power distribution while the phone is plugged in and a prompt comes up to launch the app, and from there everything is working and communicating.

From this I have concluded that it isn’t the phone, it isn’t the cables, and I don’t believe the modules plugged in have anything to do with it. Has anyone else found similar results?

2

Have you looked into upgrading the firmware ?

3

The firmware on the modules was all done recently, and they didn’t say to send in the Power Distros.

4

So have you done the reverse test and plugged different phones into the non-functioning robot? If nothing appears to work with that power distribution – it may be that the port on the power distribution block is bad/damaged.

I have also resolved similar issues by just power cycling the phone, which you did not mention, but I am assuming you have tried.

5

Have you tried upgrading the firmware on the phones? I had a similar issue and just upgraded to the latest firmware version solved it. Using the self-check in the DS or RC also helps.

6

Have you been supporting the USB’s as they come out of the modules? The poor design of the modules makes it prone to USB dropouts and brakes if used improperly.

Ways to support.

3D (We use the DJ Models)
http://www.thingiverse.com/thing:1099628/#files


http://www.thingiverse.com/thing:1096699

Or

  • Rolled up tape
  • Wood
7

We had an issue last year with one of our motor controller disconnecting from the USB even though they were supported with 3d printed supports. We chose the last resort option which was super glue the mini USB plug (the plastic surrounding the connector, not the metal itself) to the plastic on the motor controller, super glue the support to the electrical board, and zip tie the entire thing.

3 months later (without failure), we just broke off the super glue and everything was fine.

8

Interesting. We haven’t had any issues since we started using them. Sounds like it was just one bad motor controller, and not the rest?