Posted by: Rich Cumbers | April 10, 2008

CurrentCost – Initial thoughts

There is a small CurrentCost craze going on at Hursley, which involves people setting up their piece of kit and seeing what cool things they can do with the data.

CurrentCost is basically an induction meter. Clamp one end to your electricity meter, and plug in the little lcd display and (fingers crossed) you should start seeing the current electricity usage of your humble abode.

There are a couple of reasons why this is cool. Firstly anyone can set this up. No need for Andy Standford-Clark skills to be up and running with this. Therefore it is something that is accessible to the masses, which is a good thing. Using this unit you can see what happens when you turn lights on, what the dishwasher has done to your power, and from this you could start changing the way you live to try and save money. Secondly (and this is the geeky part) you can get the data from the unit via a serial cable. Every 7ish seconds the unit will send data over the wire in xml format, which you can then do what you like with.

I have already spoken to one Hursleyite that has managed to save about £7 a month as he did not realise that his home hifi was drawing a large amount of power even in standby! I have just had my first full 24 hours of using the kit and will blog about my findings later…..



  1. There were a few emails about accuracy and what is actually getting measured, and there does seem to be some answer on their web site but I’ve not found any information about the data port, and whether it’s output only! Might sign up to the member area to see if that helps.

    I’m liking it so far though. (Even though my energy use has actually gone up with a laptop running to grab the data!)

  2. My current resting usage is around the 100W mark, and that is with a shuttle pc connected to the CurrentCost meter to publish the data. I plan on going round my house in the near future and work out exactly what makes that 100W usage up. Usual suspects of Fridge, LCD TV, Sky+ box will apply!

    I just love the fact that even without using the cable and monitoring results, people can see just how much electricity they are using and change their lifestyle to save themselves cash, which is very much a current topic with the recent IMF doom and gloom report!

  3. […] a part of the “CurrentCost craze” that is rife at Hursley these days, I’ve had mine up and running for a few days and am very […]

  4. […] Rich, James and Nick have all written about their Current Cost meters already. […]

  5. Hi. I have a CurrentCost but no serial cable. Can you tell me, is the cable a standard RS232 cable? Could you tell me the wiring pinouts for it so i could make one (i have a spare serial cable and spare ethernet cable so could cut both and join together). Thanks

  6. […] thoughts: Rich, Ian, Andy, […]

  7. @mat — no it turns the serial cable has a converter chip in it, so it outputs 3.3V signals.

    I just made a cable using an ethernet lead today… see for pinout.

  8. […] couple of weeks ago I came across a bunch of blogs written by IBM folk at Hursley Park, in which they described how they’d been playing with the […]

  9. @mat – Chris Hand has described his experiences with creating a cable here. To plug it into a computer’s serial port you’ll actually need more than just an RJ45 – DB9 cable: it needs to contain a chip to convert the 3.3v TTL signal to RS232. Chris also had good results connecting it directly to an Arduino (which can handle the 3.3v TTL signal) using the Software Serial library.

  10. […] I was looking for another spare time project. About then, Rich told me about the CurrentCost device he had set up and it seemed like a fun thing to work […]

  11. I built my own cable using a MAX233 chip, powered by the CurrentCost’s AC/DC suppply. Its working great now.

  12. […] CurrentCost meter, a simple little gadget that measures power usage in your house. These are being discussed on IBM blogs everywhere, because while the device itself is very neat, it also has the ability to […]

  13. I got an Owl before the currentcost was available. Wish I’d waited as the historic data is the really cool bit.

    What they all need though is an external temperature monitor facility. Seems to me that it would good if the external temperature data was also captured. many of these units will be sat in external meter boxes, and knowing hat the weather was like at the time is important when figuring out consumption patterns

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s


%d bloggers like this: