Whilst I’m in the office waiting for my computer to be upgraded to AutoCAD 2010, I thought I’d share the realtime energy feed from my office. The system is constructed from an Arduino and some processing scripts. Physically, the arduino is wired via my own custom shield (basically some resistors..) to the pulsed outputs of energy meters within the building. The meters (Merlin Gerin PM710 Series) are all configured to pulse the output every time 0.1kWh of energy passes through them, and linked up to a single point using an 8 core (there are only 5 meters, so 2 spare cores) cable, with a common ground signal.
Two processing scripts hold things together – the first one passes output from the arduino to a MySQL database that some helpful folks elsewhere in the company have set up. After some thinking, I decided that the Arduino itself should write the full MySQL query – this avoids the need for any further codification of the information so that the processing script can understand it and then make the query.
The second processing script gets the data back out of the MySQL database at regular intervals (about every 5 minutes) and pushed it out to Pachube. The feed ID is 5889 if you want to view the raw data.
In order to simplify things for my colleagues, who are not all electrical engineers (or geeks), I’ve used the handy PachuDial application to put it into some snazzy flash dials. Unfortunately they don’t come out in WordPress…