[ale] sometimes you just need to reboot NOW!

[Alex Carver]

On 2014-07-30 11:02, Jim Kinney wrote:

> The good part is I can justify getting a BeagleBone Black box as an upgrade
> to the RasPi :-)
> 
> Now if I can do a remote power detection and determine when the room power
> is running on battery without actually wiring anything to the units...
> 

What kind of UPS are they using?  If it's modified sine wave you could
make a filter that can hunt down the harmonics.  Relatively clean AC
will have low harmonics.  The modified sine will have very dirty
harmonics, enough to pick up and distinguish between the two modes.

A true sine inverter would be harder to spot.