Jee Labs Talk

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1. tankslappa
   

   Has anyone here seen the Sky electricity usage meter (yes, Sky the UK satellite TV people)? I saw one tonight round a friends. There is a nice big LCD which tells you how much power you are using and all that, but the interesting bit is in the electricity cupboard, a mystery box which just clamps round the armoured cable going into the meter. It has no other feed, and no visible way in to change a battery so I assume it powers itself by induction and measures the consumption the same way, then sends this wirelessly to the LCD display. I wish I'd had a Jeenode with me to see if I could find the signal.

   The curious thing is it's not round just the live, it's round the whole armoured cable so I don't quite understand how the fields of the live and neutral don't cancel each other out!

   Posted 18/05/2010 23:03:25

2. tankslappa
   

   After much digging I've finally managed to find evidence they do exist... Unfortunately I was unable to find product info on the Sky "aren't we lovely" site of total green-wash! It's all waffle and spin, but nothing about this device! I guess they'd prefer customers who should get it for free to not know too much in case they ask for one!

   From what I have found in forums it's something you might get if you are on a combined TV and telephone package and ask (and ask again) and the wind's blowing in the right direction and you're lucky!

   http://www.skyuser.co.uk/forum/sky-news-announcements/30378-operation-save-energy.html

   I can't even find one on ebay!

   Still no information about the wireless operation though.

   Posted 19/05/2010 00:47:13

3. paulsbiz
   

   The Sky units are the Envi CC128 manufactured by Current Cost (). I've just bought a SWALEC badged one off eBay and it's the best electricity monitoring unit I've come across. The transmitter unit is battery powered and is claimed to have a 7 year battery life. They receiver/display unit supports up to 9 sperate devices and has a serial data output supported by third party software and Google PowerMeter. The PC link protocol allows for support of future sensors such as Gas meter readers. It looks like it may be using a Hope RF 433MHz module (see ) so perhaps we could monitor the sensors directly via a JeeNode, another project for JC ;-)

   (edited by jcw: Paul, I added <>'s around the URLs to make them live)

   Posted 29/05/2010 08:49:48

4. jcw
   

   Interesting! I've added a comment on the SIlly Science page.

   The 7 year battery life is impressive. But I'm not surprised, given that one of my power tests in the past got current drain to a few µA. It just shows that they've got their stuff done just right. So maybe we'll get the JeeNode autonomy into that range as well, one day. It's all a matter of tracing where all the micro-coulombs go: see this and [this](http://news.jeelabs.org/2009/12/19/battery-life-refinement/) weblog post :)

   We can probably rule out hooking into the Envi CC128 with JeeNodes, though. It doesn't have enough flash memory for the ZigBee protocol stack. Not to mention that any encryption measures they might use would thwart our attempts to get actual reading info. You'll have to go through their serial connection on the receiving unit.

   How is the transmitter hooked up? Current clamp? That might be a source of energy they're also using...

   Posted 29/05/2010 09:35:01

5. tankslappa
   

   Phew! I'm glad someone knows something about them. It certainly looked impressive on the receiver unit. It look kind of like a big iPhone with a huge B&W LCD screen on it. According to my friend it learns the pattern of power usage and if it sees an higher usage than it expects at that time of day it has a big red light to tell you you've left something on. I'm not sure how helpful that really is, or if it can handle bank holidays of course.

   @JC - Yup, it's just a current clamp.

   If you really want to have a go at hacking the hard way... (i.e. with no receiver) You can buy one on 19> :-)

   Posted 29/05/2010 10:46:41

6. tankslappa
   

   I saw an advert on TV last night for the UK electricity supplier E-on, it was all done in cartoon style, but from what I could see it's the same device, free to people who are pay by direct debit and manage their account online whilst stocks last (I think that's what the incredibly small print on the screen said)... Unfortunately I'm not with them so can't grab one for "testing" hopefully somebody else can.

   Posted 01/06/2010 15:07:34

7. epokh
   

   O i refused to switch to them, it was too much paper consuming. Hmmm is it worth a switch from my ScottishPower account? :-)

   Posted 01/06/2010 21:43:58