It’s been a bit quiet here the last few months as we finally got to the end of the grand moving plan! We actually moved a couple of weeks ago but the new house came without telephone or broadband… or mobile signal or TV aerial!! Today our new found productivity looks set to come to an abrupt end with the installation of a shiny new internet connection. And this is not just broadband, this is fibre-to-a-green-box-just-400-meters-away-and-same-old-copper-wires-the-rest-of-the-way broadband.

That isn’t the internet I was looking for either: I had pretty much decided to go for fibre-optic-cable-provider broadband. That wasn’t the only last minute change of plan, so to ease back in to blogging, this is the first in a series about the companies supplying our new house. In most cases I’m reluctant to go as far as recommending companies because, as is often the case, your mileage may vary. It may help someone though, so it’s no coincidence that communication provider is first up…

By appointment to Jo and JT. Purveyors of telephone and broadband, BT.

BT did well to snatch this one from Virgin Media. I’ve been looking forward to a new phone company for longer than a new house, and judging by the increasing flood of post from Virgin Media, they’re pretty keen to get new customers. Adding to the temptation, the new house was already with Virgin. I phoned them to sign up. In contrast to their cheerful letters requesting the pleasure of my custom, I got through to someone who must have previously been a doctor surgery receptionist. Partly because of the price and partly because the overwhelming impression things would not go smoothly, I changed my mind.

Eventually, after trying several other companies, I ended up picking  BT Infinity. Only time will tell if that was a good idea or not, but they’ve been ok so far. It did take them a long time to actually connect us, and it would have been nice if they could prioritise customers with no service at all over upgrades, but what I liked is that they did what they said, when they said they would. @BTCare were also very responsive and helpful, and were able to provide BTOpenzone access to keep us ticking over, which was great.

I’m much more optimistic than I was with our previous supplier- TalkTalk even seem to be messing up closing our account, so they’ve managed to keep up their terrible customer service to the very end!

…and BT Openreach.

Take one router to connect to the internet? Now I just have two boxes to power! One quirk of BT Infinity is the separation of VDSL modem (owned by BT Openreach) and Homehub (provided by BT), which even means that the engineer brings one and the other gets posted separately. I can’t imagine there’s a technical reason not to have everything in one box, but Power over Ethernet might be nice to keep the tangle of power cords under control. I was wondering how they would cope with a master socket behind the front door with no power, but luckily the new (huge) master socket is behind the TV. (Must find the Current Cost IAM to see how much power the two boxes are using.)

My second CurrentCost development board circuit

My first attempt at monitoring gas use with a CurrentCost development board was partially successful. I could get a reasonable idea of when the boiler was firing but I didn’t really find that information particularly useful. So, plan B was to actually count the pulses from the gas meter. The second circuit, which is described in the 8. More about triggering section of this 555 timer page, has been running ok for a few weeks now, so I’m thinking about actually soldering it together. Thanks to Richard for suggesting VeeCAD, which led me to TinyCad, this is circuit number two (much easier than using MS Paint!).

I’ve been using R1 and C1 values of 122k Ohms and 47u F for the 555 timer, to trigger an output pulse that’s just long enough to get transmitted by the CurrentCost development board (~6 seconds). I may yet tinker with the timing to make it long enough for three transmissions; the time between pulses on the gas meter is long enough and it might make receiving pulses more reliably.

Thanks to Mark and Andrew for some ideas for laying out a circuit on strip board, here’s what I hope is the same circuit using VeeCAD:

Might get the soldering iron out next time Jo’s away!

Update: For plenty more advice on moving from breadboard to a more permanent prototype, have a look on the Evil Mad Scientist Laboratories blog. (11 March 2010)

Update: Finally got round to pulling everything off the breadboard and soldering it together…

…and it actually still works! (14 March 2010)

My first CurrentCost development board circuit

The result of a fair bit of googling and a weekend of hacking is… [drum roll]… a circuit to connect my gas meter to a CurrentCost Envi using a nice little dev board from CurrentCost


Now I’m much more familiar with messing about with software, not all this messy hardware stuff, so I’m really hoping to get some feedback to improve this early prototype!

So, my theory is that the stuff on the left will trigger the timer on the positive edge of the pulse from the gas meter. R1 and C1 control the 555 timing; more on that in a second. And the stuff on the right (LED and the CurrentCost dev board) should be triggered whenever the gas meter is running and emitting pulses. It all seems to work, except that I can’t seem to get the timing quite right. The gas meter takes about 1m40s between pulses, and I can choose values for R1 and C1 that trigger the output for the right length of time when a single pulse is detected, unfortunately subsequent pulses don’t keep the output on as I was hoping. The best I’ve managed is with R1 = 3M ohms and C1 = 100uF, which does stay on as long as there are pulses from the meter… unfortunately just for a little too long at 5 minutes. Still, at least the CurrentCost Envi will get a reading all the time the boiler is running, and it won’t get stuck on if the meter stops on the portion of the dial where the reed switch is closed.

Any comments with glaring errors, small problems, improvements, or a completely different way to do it?!

Updated: looks like I was having problems with left and right in my first description! Hopefully I’ve got them the right way round now! (2 July 2009)

Update: for an alternative approach (latching a pulse and clearing it when the cc board transmits) take a look at the circuit and photos on John’s blog. (9 July 2009)

Update: an on/off indicator for the boiler hasn’t been all that useful. Instead, to count pulses, I’ve now modified the circuit to simply trigger an output pulse that’s long enough to get transmitted by the CurrentCost development board (~6 seconds). The circuit is described in the 8. More about triggering section of this 555 timer page, with R1 and C values of 122k Ohms and 47u F. (25 January 2010)

Update: posted some more info. on my second CurrentCost development board circuit. (23 February 2010)


I’m getting pretty close to getting the gas meter hoked up to CurrentCost. Not quite the finished thing, but was pretty excited when I got this working…


It’s a 555 timer circuit (using a low power 555 chip) which I’m hoping will keep the CurrentCost dev board transmitting a value as long as the gas meter is running. I’ve since added a capacitor to trigger on an edge so it shouldn’t keep transmitting if the meter stops on the ‘pulse’ position, which is probably around 1/8th of the time on my meter.

I wasn’t quite sure everything was working when I finished last night, but it does seem to do what I want when I was showing Jo this morning, so hopefully all I need to do is get the timing right for the gas meter, rather than me hitting a button every few seconds. More details to follow if it does work.

Graphing CurrentCost using RRDtool

I’ve not been doing much with my CurrentCost data lately, having been slightly distracted with upgrading my home server OS. Well, upgrading is possibly a slightly odd description for a running a new live CD system but to compile rrdtool I grabbed the latest version (6.0.7) of SLAX instead of SLAMPPLite which is based on an older release. I really like the new version of SLAX so I’ve been experimenting with some home server type customizations, manually so far since MySLAX creator only seems to understand older versions, but I might give SLAX Tools a go too.

Anyway, while not quite as interesting as Dale’s CurrentCost bill, I now have a working RRDtool SLAX module. RRDtool seems ideal for graphing CurrentCost data. I’m aiming for something like this example, which would be perfect for viewing on a TV using the Wii but to start with I’ve been giving it a simple trial run over the last day. Here are the results so far:

RRDtool power graph

Looking pretty good, and I think there are a few more features of RRDtool that could prove useful.

Update: found another great example of using RRDtool for CurrentCost data, which has a link to another page with exactly the kind of RRDtool settings you’ll need for a CurrentCost meter! (17 November 2008)

Update: looks like Chris Dalby has RRDtool hooked up as well now. Hope to post about RRDtool again soon with the commands I’m using; just need a couple more tweaks! (7 December 2008)

Flashing light

Roo’s been doing some open circuit board surgery on a doorbell so his house can twitter when it has visitors. By a stoke of luck (they were in the bargain bin when I needed one!) my doorbell flashes a light as well sounding a bell when it goes off:

Flashing. Lights.

Hopefully making it easy to hook up to one of these (when they’re available) with no chance of breaking the doorbell!

More broadband procrastination

Still undecided about a new phone company!

One of the early front runners, Orange, has done even worse than TalkTalk in a recent survey! BT seem to do well in various reviews, including a BBC survey, but the high connection charge still puts me off, and a colleague was recently cut off, along with numerous neighbors. for over a week! If I have to pay a high connection charge, I think I’m more likely to give Greenbee a go at £115. Sky keep putting leaflets through the door as well, and the deals do seem to be getting better- I may crack yet!

I’m still tempted to give Virgin a try though, to see if cable is any better… it’s been a while since they were NTL now!

Decisions decisions!