====== Enable the Internal Watchdog Timer ======

The ComfilePi's [[https://en.wikipedia.org/wiki/System_on_a_chip|SoC]] has an internal watchdog timer that can be used to automatically reboot the system should it ever become unresponsive.  It is also recommended to [[::comfilepi:read-only_file_system_with_overlay|enable the read-only file system overly]] to protect the file system from corruption should such an event occur.

First, verify that the ///dev/watchdog// device exists:

<code>
pi@raspberrypi:~ $ ls -al /dev/watchdog*
crw------- 1 root root  10, 130 Feb 14  2019 /dev/watchdog
crw------- 1 root root 251,   0 Feb 14  2019 /dev/watchdog0
</code>

Uncomment the following lines in the file ///etc/systemd/system.conf// and then reboot.  See [[https://manpages.debian.org/bullseye/systemd/systemd-system.conf.5.en.html | the system.conf documentation]] for more information about these settings:

<code>
RuntimeWatchdogSec=10
RebootWatchdogSec=10min
</code>

To test if the watchdog service is working, obtain root privileges, and then create a kernel panic with the following:

<code>
pi@raspberrypi:~ $ sudo su
pi@raspberrypi:~ $ echo 1 > /proc/sys/kernel/sysrq
pi@raspberrypi:~ $ echo "c" > /proc/sysrq-trigger
</code>

If the watchdog is working, then after about 10 to 20 seconds the ComfilePi should reboot.

[[comfilepi:index|ComfilePi - Industrial Raspberry Pi Panel PC]]