Tag Archives: computers

Current Cost – watt hours and pachube

This is an email i sent to JT  so I apologise if it doesn’t make sense to y’all. Please ask questions if you don’t get me!

So we have this ‘Current Cost’ meter thing (free from Southern Electric) at the house. It’s a small wireless electricity meter. Well it’s more of a monitor or display actually but you get me….[insert pic].

Long story short, I’d noticed the RJ45 on the bottom and it’d got me wondering. A few google searches later and whammo i’d found what I needed. A bit of hardware, a bit of software (links on manyfacturers website!) and whammo….

I wired up the current cost (enegry meter) at the house to my laptop and it’s uploading to this Pachube (bless you) website:

The graph is a bit useless atm (no history or dates on it 🙁 ) but the program here:
Could probs snazz it up a bit.
There seems to be a binary pattern from some device that is turning on and off at regular intervals and using ~100w… i wonder if it’s the compressor on the fridge/freezer as it goes on thru the night lol.

Graph of peak watts and temperature from current cost and excel

Graph of peak watts and temperature from current cost and excel

The long jittery spikes are the washing machine/dishwasher/tumble dryer (the last being the biggest draw lol).

One guy is even trying to record signatures for each appliance and then work out from the data which appliance is causing the spikes.
The idea behind this is if you can work that out, you can make a pie chart of the biggest consumers…

I have more results than are uploaded; i created a funky excel file which Should update from the mdb created from one of the apps i’m using but atm i think the file is locked or summat :(. Made a pretty graph to! Also predicting the future temperature based on a polynominal curve or something lol.

All gd fun. Now i jus want one of these tiny minuture computers:
or this awesome plug pc:
http://www.pcpro.co.uk/news/258238/plug-sized-pcs-arrive-in-uk.html (sweet) (Ubuntu on a plug [ via Youtube])
to record/upload the results, although it would make more sense to use the ipcop or home server since they are always on and the current cost device is wireless. (unfortunately our model does not have internal data logging 🙁 ). Don’t know how to work out kwh from current usage of watts every 3 seconds… i might be able to put something from averages tho. Any suggestions  anyone? I might just be being dumb lol.

Now all we need is the x10 plug thru devices to monitor electricty usage (by appliance) and bobs your uncle – we know exactly where the electricity is going.

IMO  (as a soon to be Building services engineer in training) this technology should be wired into all new houses in the actuall plug sockets. Want to know which of your kids (or indeed partner) is using the most electricity? 😉

The trickle usage these measuring devices could be designed to run on could easily be offset by a small(ish) solar pv installation too! (i’m talking around 10-30wh/day here 😉 ).

Oh and here’s how to connect the current cost to pachube:

On the upside i’ve also unplugged the fancy pants MPPT  solar charge controller and hooked the install back up to the basic on/off controller, and now it’s definetly shifting amps! I was a bit worried that in full sun 53watts of panels was ONLY putting through 0.3-0.1a @11.7 (i know, discharged). Hmm gonna have to find out whats wrong with fancy pants, he wasn’t cheap! :'(

Day 5 – Datacentre work

Today, I was planning on scanning through NaBlogPoMo’s blogroll and pick out a couple of good ones. However, life always likes to intervene, and at about 1730 a server decided to fail. Wouldn’t boot up, nothing on the console.

As I’m on call this week, it was my turn to head into the datacentre, to have a look and try to fix it. For some reason, whilst it was showing network lights (so the network card was obviously initialized), it wouldn’t show anything, nor would it respond at all to server commands. I was planning to switch the hard-drives into a spare server, but a colleague of mine called to say that I should first reset the BIOS. (Take the battery out, short the contacts).

In the end, doing that cleared the problem, and the server came back online OK. A little confused – it thought it was 1400, rather than 2100, but apart from that it was fine.

I’ve only ever seen that trick work once before, on an old desktop machine. Still, that’s a good thing to try – if the BIOS confuses itself into oblivion, you can reset it by taking the battery out and shorting the contacts. (With a screwdriver is normally easiest – you’ll probably just have used it to open the case.)

Another hardware trick I often use, I’m not sure how relevant this will be if you’re not in the UK – Plug the computer you’re going to work on into a power socket, but make sure the socket is off at the switch. The earth pin is never disconnected – the switch will only ever interrupt the power flow, not the earth. So, if you’re not sure about static electricity in your environment, its a good way of making sure you’re clean – as the earth will be connected to the computer’s case via the PSU 🙂

A quick spelling / grammar question to those reading – is “online” a valid word, or should it be written “on-line”? I’m never certain, but my spell checker seems to think that it should be “on-line”…

General Update Ramble

The following is a random update, covering everything from my explorations of Linux to life stuff. Feel free to skip if you don’t care 🙂

Hardy Release Party

Was really nice, once I’d got past my initial reluctance to go and the butterflies in my stomach as I traveled to it. I said on IRC before I left, that the first person to recognise me, would get a drink on me. Daviey failed, he was outside having a cigarette when I finally arrived. To be fair, he wasn’t on the IRC channel when I said about the free drink… I managed to get lost, walking from the tube (Embankment) on the way to the pub – asked directions three times. Had the obligatory chat with Daviey about asterisk (I like asterisk!) and some of the pros and cons of the FreePBX interface add-on. (As suggested by Popey on the mailing list. Thanks!)

I went in with Daviey, and saw Alan Pope. He was in the middle of a conversation, but was about to say “hello Kirrus” to get his free drink, when Josh (Jerichokb) popped up, and nabbed it first :). Funnily enough, we had this conversation on IRC before I left:

<jerichokb>    Kirrus: thank you in advance for the beer :)
<Kirrus>       jerichokb, don't count your chickens...

Heh… I guess he can count them after all 🙂

I had a really nice time, which is *really* unusual for me in a room with that many people in it. (I don’t do lots of people… I normally can’t cope, and leave asap, or sit in a corner hiding…). Sad to leave at 9, but I got lost 4 times(!) on my way back to the tube station, (asking for directions each time… one guy gave me dogy ones…).  Next time I find a good map. Missed the train I was aiming for, and ended up taking the last train, got home midnight. (Yes, three hours travel. Missing the train will do that for you.)

Distro Experimentation / Hard Drive Failure

Well, my CentOS install died with my harddrive, about 2 days after my posting about it. CentOS is useable, and is quite nice, though I didn’t reinstall it when my new drive arrived. Unfortionatly, it turns out that my new drive has some bad blocks on it. Repaired the filesystem using “e2fsck -c” on the live cd, and reinstalled gutsy. Upgraded to Hardy RC. A lot of work. I’m going to have to boot back into the LiveCD sometime and check the filesystem again, to see if there’s any more corruption. If so, I’m going to have to get another Harddrive, and RMA this one. Just what I didn’t need with my dwindling savings and no job. Update:(Thanks, as always, to the Ubuntu-UK irc guys for the help and advise as I tried to repair my partitions)


I’ve had 2 interviews so far, one at Codian, one at Canonical. I’d  really like to get the Canonical one (working in a datacentre, looking after servers), as it sounds like an enjoyable thing to do, that and giving me plenty to learn. But, I don’t think I will. (Heh – my natural state after any interview. Then getting the job is a pleasent surprise rather than a disappointment.) Millbank tower is NICE, and the commute into Vauxhall fairly simple.. I just take a slow train from a town about 3 and a half miles away… an hours walk, or 15/30 minutes cycle depending on the traffic, and which way you’re going. (To is easier. One big hill up, then mostly downhill to the station.) I’m still awaiting a reply from Canonical HR about blogging guidelines as applied to interviewees, so I won’t go into too much detail about that interview here. Suffice to say, it was interesting.
The Codian interview was by far the most difficult, I was asked a tonn of questions by three different people, over 2 hours. Decimal to binary (on a whiteboard).. I’m a bit rusty at, not having done it much before, but got there in the eventual end. Decimal to Hexadecimal, mathmatics is not my strong point, but again, got there in the end. (6E == 110).Very friendly receptionist 🙂

I’ve one interview/meeting left, at Positive Internet. Sounds interesting…

If you know of any Junior/Trainee Linux/Ubuntu-Based jobs in London going around, let me know.

To Do:

  • Process, upload and blog photos. Recharge camera’s battery (rarely need to do!)
  • Continue Job Hunting.
  • Look at the feasibility of moving onto a new blogging platform, but staying with my current email and domain host.
  • Hunt for jobs.
  • Bug Triage.
  • Think about applying for temp work to tide me over.

Useful Ubuntu Things to Remember

  • To open a terminal in Ubuntu, go to Applications > Accessories > Terminal
  • To add shortcuts from the applications listing to your desktop or top/bottom panel, browse to the location of the program under applications, click on it DON’T LET GO, and drag it to the bar at the top, or onto you desktop. Let go.
  • To run a unattended upgrade on an (K/X/U)buntu machine use the following command in a terminal:
apt-get update; apt-get upgrade -y
  • If you only want the upgrades to be downloaded, and not installed as well, then use this one (I think, this hasn’t been tested, and you could probably do it a bit more neatly with -dy):
apt-get update; apt-get upgrade -d -y
  • Most linux variants store their programs (e.g. lspci) under /usr/sbin
  • To force evolution (linux version of MS Outlook) to close completely, open a terminal, and run the following command:
evolution --force-shutdown