[arm-allstar] Power failure and SD card

[Doug Crompton]

In most cases a simple loss of power will not damage an SD card BUT power
cycling which often happens in failures is not good and can corrupt things.

I have UPS and a automatic generator which takes care of the problem but
most do not so at least a small UPS is a good investment. With Linux you
can have it shut down gracefully by command of the UPS after a certain
amount of time

The power down board that George, WB3DZZ sells is also a good way to do it.
This is used in his radioless node and also as an option in his yellowbox
nodes. He also sells these boards separately. It monitors input voltage and
if it goes away for more than 5 seconds it tells the Pi to shutdown
gracefully running it on a rechargeable NiMh 9V battery until it shuts down
which usually takes less than 20 seconds. This was intended for use in a
vehicle so you can just shut off the ignition and walk away but would also
work well in a fixed environment. The board is followed by a power supply
to 5V so you can run it on any battery or fixed source of 9 to more than 12V


*73 Doug*

*WA3DSP*

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