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.

# Debian et al
sudo usermod -aG dialout user_name
# or
# uucp on Arch
sudo usermod -aG uucp user_name

# user must log out and log in again

This fixes about 99% of serial issues.

Alternative, for a systemd based distro, all the following udev rules (e.g. add file /etc/udev/rules.d/45-stm32.rules with content below)

UBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="5740", MODE="0660", TAG+="uaccess", ENV{ID_MM_DEVICE_IGNORE}="1", ENV{ID_MM_CANDIDATE}="0"

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="df11", MODE="0660", TAG+="uaccess"

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
```