During the day I gave a brief talk about what the Mazzini project is exploring and also asking who would be interested in buying one of the bare energy-measurement boards.
What You'd Get
You'd get a PCB with the components to measure and control the power, plus terminal blocks to wire it into the mains electricity and a set of headers to connect it to an Arduino. This is very much aimed at people who are happy playing around with electronics, and are happy connecting things to the 240V AC mains electricity.
You'd need to provide your own Arduino, and any other components (such as the temperature or light sensors that I've added to the prototypes).
It wouldn't be an Arduino shield in the strict sense, because it wouldn't fit directly onto an Arduino board. That's because I think it's better to keep the mains electricity a bit further from the Arduino electronics. The Arduino connections are all electically isolated, but I'm not happy having them in such close proximity.
What I'm Looking For
I've had a few responses now from people who are interested in getting their own Mazzini board, but I want to find a few more people who'll agree to pay £35-40 to get one of the boards sooner rather than later.
Once I've got a dozen people signed up then I'll get the first batch of PCBs laid out and built. So if you want to join the early adopters, send an email to firstname.lastname@example.org and I'll add you to the list.