[arm-allstar] RPi graceful automatic power shutdown

[Doug Crompton]

I have added a howto to the hamvoip.org web page detailing a circuit to
gracefully shutdown an RPi 2/3 using a simple switch or ignition switching
in a car. This would allow you to simply turn on your mobile node by just
turning on the car and when leaving the car just turning off the ignition
the node would tell you it is shutting down via the radio and then
gracefully shutdown the Pi and turn off all power to both the Pi and the
radio.

BTW - tests show that using the beta DNS code a node becomes ready to
connect to other DNS enabled nodes in seconds after boot making quick on
and off portable or mobile nodes work great.

You can see the howto at the hamvoip.org site or directly at:

https://hamvoip.org/hamradio/power_shutdown_monitor/

The latest (Dec 4, 2017) update has the modified shutdown_monitor.sh script
to support this circuit.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*