[Noisebridge-discuss] Long-lived, battery-powered AVRs

[Jonathan Lassoff]

I'm interested in helping someone I know with a project to build a
remote AVR-based sensor (arduino parts) that will use an Xbee to
detect a gate latch opening and closing. Since it's in a bit of a
remote spot, it has to be battery powered.

As we're brainstorming ways of saving power, we thought of a couple of
ways of not keeping things powered all the time:

 - Use CPU sleep on the AVR so as to only periodically wake up and
poll the state of the gate sensor. I think the Xbee would still draw a
bit of power still.
 - Use a transistor that can trigger a flip flop with a transient
amount of power from a coil in the sensor, and use that state to
switch the AVR on, and have it turn itself back off, once done
signaling.

I'm sure there's been some past work on remote AVR sensors before, but
I can't find anything that seems quite like what we're trying to do.

Any advice on something like this?

Cheers,
jof