UART adapter

The USB-C UART adapter can be connected to the PineTab2 to debug boot issues at the early boot:

• Plug the adapter face-up in the USB-C port furthest away from the power button. If all the lights are lit, you have the wrong port: only the green light should be lit when you first plug it in.
• Plug USB-C cable into the port on the adapter marked “DEBUG” (the other port can be used as a power delivery passthrough so you can charge and debug at the same time)
• Open a terminal window
• Install minicom or screen via your distribution’s package manager, if you don’t have it installed already
• Connect via minicom using sudo minicom -D /dev/ttyUSB0 -b 1500000 or via screen using sudo screen /dev/ttyUSB0 1500000
  • Ubuntu-based distro users may encounter the error, “cannot open /dev/ttyUSB0: No such file or directory”. If this occurs, check the output of sudo dmesg --follow and unplug/replug the USB to look for any errors. If you see an error like, “usb 1-1: usbfs: interface 0 claimed by ch341 while ‘brltty’ sets config #1”, then the brltty service is likely conflicting with this device. Brltty provides access to blind users who use a braille display: if you do not need this service, try disabling it using these commands:
    • sudo systemctl stop brltty-udev.service
    • sudo systemctl mask brltty-udev.service
    • sudo systemctl stop brltty.service
    • sudo systemctl mask brltty.service