A friend spotted an energy meter in the latest email from Maplin and it prompted me to do something about a project that has been in the back of my mind for a while. I really need to review the various kit we leave plugged in all the while, and maybe replace some of the older kit with more efficient items. Having tried the simple plug in devices that measure a single socket, I know this is not the solution I need. However the various energy meters I have seen in the past were, like the Maplin unit, a standalone afair. Whilst some do keep historical data, I wanted something I could extract from and built my own graphs.
Pretty much all you need to know is covered over at Dale Lanes’ blog in this post. Worth mentioning is that I picked up the current cost device from the eco gadget shop, which arrived next day. Various blogs report some places selling older stock that you can only communicate with at 2400bps and that don’t save historical data. Certainly the one I received looks to have the later firmware, and I’m connecting at 9600bps and retrieving historical data from it. My cable to connect to the PC, I choose to go with the USB one from the companies ebay shop, which also arrived next day in a jiffy bag small enough to make it through the letterbox. The cables pretty long at over 9ft, so should be fine where ever I want to arrange the meter and PC.
I had to grab the USB driver for the cable from Prolific web site, as I was testing with X30 Laptop running XP. Also updating to .Net framework 3.5 to get Dales’ Windows GUI application to run. This ran just fine, and the ease with which I had everything up and running was a little worrying. So I quickly moved on to have a try with the latest Current Cost Python code which again was up and running in a matter of minutes.
So I know have a pretty neat solution to track the house electricity usage, what I’m currently lacking is much data, having only unpacked and plugged the current cost meter in last night, so for now I will just leave it plugged in and the PC attached to grab and graph me a weeks worth of data.
When I return to the project, we can start trying to change how we use appliances around the house and see what difference we can make. I also want to look at what I connect the current cost meter to, as the X30 is my test/travel laptop. I have a mini-itx box sat under my desk spare if I stick with the Windows software I’m using now, but would rather like to dust off a spare NSLU2 (Slug) I have, or the Viglen MPC that I never really found a use for.
I’m interested in comments and suggestions if I should go with the Slug or MPC, I’m thinking I would use the device as the home web server too, so other projects would publish data to it, and combine with the energy graphs and information.
