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Phone/REV disconnects with "stuck USB write(12 bytes)" Exception

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  • Phone/REV disconnects with "stuck USB write(12 bytes)" Exception


    Every now and then we get disconnects between our phone and REV hub. Some days, it doesn't happen at all, while others (like yesterday) it happened four times.

    I pulled the log files and found the following and am looking for ideas/suggestions on how to fix the issue.

    01-10 21:48:31.804 11707 11980 E MonitoredUsbDeviceConnection: watchdog: stuck USB write(12 bytes) threadId=1048 TID=12072:: serial=DQ170Y6E closing device
    01-10 21:48:31.804 11707 11980 V FtDevice: vv********************DQ170Y6E closing********************vv 0x02378ccf
    01-10 21:48:31.805 11707 11980 V FtDevice: DQ170Y6E stopping thread readBufferManager
    01-10 21:48:31.805 11707 11979 V FtDevice: DQ170Y6E thread readBufferManager is stopped
    01-10 21:48:31.806 11707 11980 V FtDevice: DQ170Y6E stopping thread bulkPacketInWorker
    01-10 21:48:31.809 11707 11992 V RobotCore: event loop: device has shutdown abnormally: ABNORMAL
    01-10 21:48:31.810 11707 11992 V EventLoopManager: event loop: detaching device DQ170Y6E
    01-10 21:48:31.810 11707 11992 I FtcEventLoop: vv===== MODULE DETACH RECOVERY: disarm REV Robotics USB Expansion Hub Portal [DQ170Y6E]=====vv
    01-10 21:48:32.807 11707 11981 V LynxUsb : exception thrown in incoming datagram loop; ignored
    01-10 21:48:32.811 11707 11981 E LynxUsb : org.firstinspires.ftc.robotcore.internal.usb.excep tion.RobotUsbStuckUsbWriteException: watchdog: stuck USB write(12 bytes): closed DQ170Y6E

    The entire log file can be found here for those who want to take a look:

    Note, we are using the g4 play and are also remote debugging/deploying. And the only way we have found to resolve the issue is to physically disconnect and reconnect the phone.

    Any help would be appreciated as we have our last tournament in 8 days.

    Thanks in advance

    POC- 3763

  • #2
    Update the firmware of all hubs to 1.8.2, which had a fix for this issue (when paired with the 4.X FTC software)


    • #3
      Is there a link to the bug fix/patch notes? Just wondering what else got fixed.


      • #4


        • #5
          Yea, I was looking at that page, but it's high level. I guess they don't publish a detailed bug fix list.