Monitor a power source

Is there any way/suggestione/idea I can create a device to monitor a power source (220V) using a Panda II? Basically I need a device (that I will connect to an UPS, of course) that will detect a power failure on a 220V domestic line, and will write the event on internal SD.


There are a couple ways to do that.

  • Grab a couple diodes and an opto coupler
  • A wall wart and measure it’s voltage (make sure the output is max 3.3V)

So you suggest to create a sort of voltmeter on the power source?

Does exist something assembled? I don’t like to insert on 220V something I’ve created (I’m really a newbie on this)…


Then use what i suggested. Grab a wall-wart and measure it’s voltage with the Panda. (again, 3.3V max, if higher use a voltage divider:


I’m sorry, I didn’t understand that point/option…

Great idea, thanks.
I can buy a multivoltage walwart as the one I use to power on the Panda, set it on 3.0V output option, and measure that voltage with an analog input. Perfect…


Avago makes a line of isolated voltage/current detectors for just this purpose:

See this

Gus, that will not work if there is no load.

Many ups’ have a serial output for this purpose. Have a look in the manual. It might even be able tell you other info like load.