Serial USB checklist - stronnag/mwptools GitHub Wiki

Unmaintained Article Please check the manual for more up-to-date information.

The users using mwp (inav-configurator etc.) must be members of a group that has read/write access to the serial ports.

• On Arch (and derivatives) uucp
• Most other distos dialout
• FreeBSD dialer

e.g.

sudo usermod -aG dialout user_name
# or             uucp on Arch
# user must log out and log in again

This fixes about 99% of serial issues.

Other points:

• ModemManager (possibly older versions only) may interfere with the port. Either disable it or write a udev rule to avoid it

  sudo systemctl disable ModemManager
  sudo systemctl stop ModemManager
  

  Note this may prevent USB Mobile internet modems from working correctly

• Some machines / distros / BIOS may cause USB autosuspend to be set. This may prevent communications with the FC. See this stackoverflow article for solutions. The following script will check for this issue:

  #!/bin/bash
  for D in /sys/bus/usb/devices/usb*
  do
    FN=$D/power/autosuspend
    if [ -e $FN ] ; then
      susp=$(<$FN)
      if [ $susp != 0 ] ; then
        echo "Autosuspend set for $FN"
      fi
    fi
  done