Connecting a serial-over-USB device to a WiPy?

  • I have a battery charger that can be connected to a computer using a serial-over-USB interface; it’d be great if I could connect it to a WiPy for data collection / notifications. Any thoughts on how to do this? I’m guessing the WiPy can’t be configured as a USB host ...

    Thanks in advance,

  • We are building a custom expansion board that will have a USB host port for bringing IOT to ordinary USB devices. If you message me I can keep you updated of our progress. First batch of boards are due to arrive next week.

    Update: Check out the First look: USB Host Expansion Board by Semireg

  • Unfortunately, that’s what I expected … was hoping for a magic cable :)


  • @tshead
    You would have to get the UART signal before it goes into the CP210X, maybe physically opening your charger and finding a way to connect? If you can’t do that then it’s not possible.

  • @robert-hh : Thanks for the quick response! I want to believe you, but this seems too simple :) To clarify, the device in question has a USB mini-B receptacle; when I plug it into my Mac, it uses a silabs CP210x driver to expose the device as a serial port at /dev/cu.SLAB_USBtoUART … are you saying that there’s some way to open-up a USB cable and wire it to the WiPy UART? My assumption was that the USB signal on the cable at that point wouldn’t be usable with a UART.

    Many thanks,

  • @tshead You can use the machine.UART class for that purpose (see
    You can for instance use UART1 for that purpose (P3 and P4). Just check that both sides work at 3.3V level Otherwise you would need a level converter.

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