Small thing this weekend, but kinda working up to the big project starting next month...
Tweaked the code for relatively fast and low-energy start-up, with energy harvesting applications in mind eventually (a little like this JeeLabs stuff
http://jeelabs.org/2015/03/18/micro-power-snitch-last-part/ but I failed to get my current-clamp-driven stuff working yet).
So I have a single unit powered from my rather quiet urban turbine. When it spins up at all it sends JSON plain-text stats on the ISM band at 868.35MHz, initially just an ID to minimise energy requirements, then, if it stays running, some other data periodically (supply voltage and temperature at the moment).
Here's a sample of the log entries.
[ "2015-03-22T16:10:53Z", "", {"@":"b39a"} ]
[ "2015-03-22T16:10:55Z", "", {"@":"b39a","B|mV":3247,"T|C16":376} ]
[ "2015-03-22T16:11:13Z", "", {"@":"b39a"} ]
[ "2015-03-22T16:11:23Z", "", {"@":"b39a"} ]
[ "2015-03-22T16:11:25Z", "", {"@":"b39a"} ]
[ "2015-03-22T16:16:29Z", "", {"@":"b39a"} ]
[ "2015-03-22T16:16:33Z", "", {"@":"b39a","B|mV":3247,"T|C16":375} ]
[ "2015-03-22T16:16:41Z", "", {"@":"b39a"} ]
[ "2015-03-22T16:16:43Z", "", {"@":"b39a"} ]
[ "2015-03-22T17:03:39Z", "", {"@":"b39a"} ]
Not a peep out of it for over 4 hours, since of course doing anything with a wind turbine other than trying to take it down causes the wind to drop.
Rgds
Damon