Reboot Modem on Pinephone in Mobian

[lagrang3]

There's probably a better way, but you can monitor if /dev/ttyUSB0..3 exists. Those 4 serial ports disappear when the modem disconnects. Then restarting eg25-manager will bring the modem back up. It takes 30+ seconds to boot up before the serial ports will return. You can see what is happening in dmesg.

This is a simple bash script that I used. It has to run as root. It is an endless loop. You could take out the loop and the delays and run it with cron, as root. Or run it as a service.

Code:

#!/bin/bash
FILE=/dev/ttyUSB2

while :
do
if test -c "$FILE"; then
  sleep 5
else
  systemctl restart eg25-manager
  sleep 60
fi
done

I am having problems with the modem as well. Based on your suggestion I created the following script `/home/mobian/bin/test-and-connect-modem.sh`
that restarts the serial port if the devices are not present.

Code:

#!/bin/bash
FILE=/dev/ttyUSB2

if ! test -c "$FILE"; then
  systemctl restart eg25-manager
fi

Then in order to check this regularly I suggest using `cron` jobs as root:

Code:

sudo crontab -e

and set the following rule that executes every minute

Code:

* * * * * /home/mobian/bin/test-and-connect-modem.sh