Comments on: Energy Monitor – part 2

By: dylan

dylan — Thu, 06 May 2010 14:35:15 +0000

There’s a project article using this device at http://www.ibm.com/developerworks/xml/tutorials/x-ameetut/index.html

By: silly-scientist

silly-scientist — Sat, 06 Mar 2010 00:00:54 +0000

Ha! Awesome. That sounds pretty nasty work though… I wonder why Owl made it so hard? But pretty classic code cracking stuff! Would be interested to see if you get it all deciphered and then integrate it into Google Power Meter (see my post on that…)

By: Steve

Steve — Fri, 05 Mar 2010 23:25:52 +0000

Could be interesting.

I had a theory based on something I read on another site though, and I think I’m onto something.

I took the data I snooped off the USB and put it into excel. I then assumed (hey, nothing like a crazy assumption) that the values were sampled radio data, thresholding the values at the average of the data, giving me a bunch of 1s and 0s.

I know that the ID of my transmitter at the moment (it changes if I reset it) is 596 and that they say there are “>4000 IDs per channel”, so I assumed 12-bit ID, then created a sliding 12-bit window and created decimal values across the data. Then I searched for the ID – boom, it’s there, repeatedly, and the bits surrouding it rarely change either – suggesting there’s other constant data too – it’s a pattern beyond randomness, I’m fairly sure.

Now how about THAT for some detective work!

By: silly-scientist

silly-scientist — Fri, 05 Mar 2010 23:13:26 +0000

Hmm, sounds nastily more complex than mine… it might be worth me seeing if I can put it on the USB analyser at work and see if we can get a dump of what’s going on – hopefully that might be a bit more enlightening!

By: Steve

Steve — Fri, 05 Mar 2010 21:16:46 +0000

My standalone receiver doesn’t appear to have any easy to access outputs – not even found a JTAG or anything. My USB receiver is weird – just a pair of HID devices, one of which gets written to (same packet every time) and the other replies with what i can only assume is what’s buffered up in the radio receiver. Incidentally, the radio in the USB receiver is from an Oregon Scientific weather station… o_O.

Once I’ve had a chance to read the data I’ll hopefully be able to figure out what it is.

Replaying the USB command in Linux hasn’t worked yet either. I wish it was as simple as RS232 and XML!