It's been a while since I announced my latest research project, the controllable electricity meter, and although I haven't written any more about it (apart from the occasional comment on my twitter feed) behind the scenes it has been steadily progressing.
The initial hardware prototype has been finished and debugged, and now I'm working on the software side of things. There are two strands to the software: there's the code which lives in the energy monitor itself, measuring the power consumption, etc. and reporting it at regular intervals; and also the code that runs on a PC collecting the reported results and doing something useful with them (such as displaying a graph of your power usage).
The current prototype uses Bluetooth to communicate the results to a PC, and on Friday I managed to get a live display of everything that the hardware is monitoring up and running on my laptop. Covering the light sensor gave an immediate drop in the recorded light levels; the voltage graph showed a nice sine wave of 240V AC; and the current display rose and fell depending on the power consumption of whatever I'd plugged into it.
This live data output won't be in the final software - it's far too chatty to be useful - but it's a handy development tool to let me check that I'm getting valid data through to the computer. The next step will be to convert the voltage and current readings into a power consumed value, and then get the Mazzini box to aggregate the data into bigger chunks and only report it something like every ten minutes.