A Blog by Tim Bishop

It seems to be the “in thing” to do at the moment; get a Current Cost electricity meter and produce pretty graphs. I couldn’t resist, so I picked one up with a USB cable to connect it to my server.

The system itself is trivial to install. There’s a box with a clamp that attaches to your mains supply (your side of the house meter), and a display which can be placed anywhere in your house (within the wireless range of the two units). Turn it on and it just works. I adjusted the electricity prices, but it’s not clear how accurate that’ll be given the multiple tiers of pricing we have.

So even without connecting it to a PC it’s a pretty useful device. Although I am developing a habit of running around looking for what’s caused the usage to jump up. Hopefully that’ll pass

Connecting it to my FreeBSD server took a bit of effort. It needed the ucom module, but (I think) because I had ugen built in to the kernel it was using that instead. A kernel rebuild to include both fixed it. I also got some strange issues connecting to the device. On the first connect I got the expected XML output, but on the second connect I got messed up output. Turns out not to happen when I use my script to parse the data, so I don’t think I’ll worry about it.

I did the graphing using rrdtool. I’d like to take the credit for doing that, but I just stole all of Paul’s work. Thanks Paul

The excitement has gone now, but I’m sure over time the data will prove to be interesting and useful.

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2. Connecting to an LDAP server using Kerberos authentication in Perl It took me a while to figure this code out, and there seemed to be a lack of complete examples on the web to do exactly this, so I thought I’d document it. I needed to connect to an LDAP server using a Kerberos principal for authentication from within a Perl script. This meant that [...]...

This entry was posted on Wednesday, November 5th, 2008 at 1:10 pm and is filed under Computing, General. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.