I brought at efergy energy meter from Oxfam and have had it running for a couple of days and it is already starting to annoy Sarah. Next up is to try and grab some of that data and graph it.

I sent an email to efergy asking if they could let me have some more information about the specs of the signal. I got a really good reply from them saying that they could not really give me any more detail than is on the box which is what I expected but the guy there did seem interested in what I was doing and took the time to write out quite a detailed reply so I like the company already.

The spec says that every six seconds the transmitter spits out a signal on the 433Mhz band so my next step is to try to capture that. If I had more than a multimeter then this may be a lot simpler but hey lets give this a go. I am going to get a 433Mhz reciver for a garage remote so that I can get the baseband signal. Assuming they are sending very little data then the bandwidth should be pretty low so I think that if I can get the arduino to capture the output at say 20kb/s then I should be able to examine the signal if it is less than 10Kb/s. It may be simpler to just try and grab this direct from a parallel port.