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Issue with USB not connecting

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    • 2025-05-06 at 6:49 PM #19101
      Stephen H
      Participant

        On a Linux box(but really any platform I suspect), especially with mayflies that have been in the field for a time, the USB port goes dead.  Strangely the Mayfly seems to continue to work, you just can’t connect to the serial port, and or upload new code.  You can tell because with the USB switch(the double dip switch for power light and USB light) turned on and the main power slide switch set to the on position, and the Mayfly connected to a USB port on a laptop(in my case an Ubuntu linux box), the USB indicator light still stays off or is dim, and you’re unable to connect because the USB port never recognizes the CP210x driver.  If you cycle the main power slide switch a couple of times, while pressing down on it lightly, the light eventually stays on bright orange. Once it stays on, then when issuing “lsusb” you’ll see the CP210x driver active.  After that you’ll be able to connect to the serial port, and upload code with the Arduino IDE, or PlatformIO. I think the cycling just cleans the contacts on the power slide switch.

      • 2025-05-15 at 12:22 PM #19113
        neilh20
        Participant

          Nuts that it sounds like the switch might be oxidizing. The switch solves a power vampire problem by switching off the CP210x – so I would expect the processor to carry on working.  You might check what the humidity levels are in the unit, ensure that its largely isolated from fogs and possibly put in some dessicant to dry it out. At one point I mad some electronics (not the Mayfly) in a temperate forest  – and some fungus or something grew across the reset line causing the processor to permanently reset.

          For purely monitoring the processor, I use the FTDI link to do that. This means it can be monitored in the field for its current state, and doesn’t reset when connecting to the USB .

          Diagrams here, showing only the Tx line connection https://github.com/neilh10/ModularSensors/wiki/Test-Equipment-FTDI-cable

          For a full connector with Rx and Tx it can also download programs to the processor.

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