Benjamin Ellis

CurrentCost Graphs – Monitoring Home Power

It might not look like it, but that is a wondrous thing. It represents the next step in home hacking with the current cost meter. It is a lead which connects the current cost meter to the serial port on a lower power PC that runs a simple Perl script that records our power usage. The PC runs a script that captures the information from the current cost meter (current power used, in Watts, and temperature in ‘C) and build pretty graphs that are then published on a local web server.

Here are some of the useful resources I used to get it done:

• This original post from jibble.org: making graphs using the current cost device.
• Crouching Badger’s experiences with the USB version of the cable with links to a simple perl script.

The Jibble post got me started, although not being a PERL programmer or RRD user meant some of the “easy to make” changes weren’t actually that “easy to make”. Having learnt RRD a bit more, I’m impressed with it – great for performance monitoring of all sorts of thigns. It will take something more to move me to PERL as a programming language – PHP is as non-visual as I’m going to get. Some other pointers that helped (and give you an idea what it is all about):

• Dale Lane has done a fair bit – it was good to meet him at HomeCamp (I like Dale’s daily electricity bill too – I’ve build something similar, but taking the Kilowatt hours figure from the Current Cost Meter).
• Likewise Nicholas O’Leary has a series of posts.
• There is also a Google code repository.
• Ben Smithurst’s posts were also very helpful – a full script that updates rrd and an sqlite database too.

A slight warning: the commonly used PERL script fails when the temperature goes bellow 10′C though (since the current cost prints a leading space then, which causes the perl string matching clause to barf) – keep your current cost warm or fix up the script .

I have been amazed at the power of measuring usage in changing behaviours. Measuring really is the first step to managing. Even more excitingly, I have noticed that my gas meter is readable (via a magnetic or optical sensor) so I should be able to track that too soon – as if I’m not driving the family crazy already. Here’s a day of our electricity use (with min, max and average power):

Reducing the Noise from a G4 Apple Mac

First, a disclaimer: Don’t do this unless you feel confident and safe to do so . This will void the warauntee on your G4, big style, but hey… It’s so old I doubt anyone would repair it anyway, right?

With that said, making an old Apple G4 quieter is a fairly simple job. There are three fans that need replacing, two 60mm fans in the power supply, and one 120mm fan that cools the CPU. Some would argue that the two smaller fans make the bulk of the noise, but my G4 is in an audio environment, so I wasn’t taking any chances. Besides, the bearing on the 120mm fan was wearing out and emitting that telling grind of death noise.

The best on-line piece on dealing with the G4 noise is on xlr8yourmac. Normally I get components for quieting machines from QuietPC, but because of the special fan sizes this time I went to FrozenCPU (an insanely large collection of PC bits and pieces, but a carbon foot print fail, since my fans went: China -> US -> UK). It turns out you can actually get a full kit here, but not so cheap. 

I ordered a SilenX 120x120x38mm – 18dBA – 90CFM iXtrema Pro Fan and two Cooljag Everflow 60mm x 25mm Fans with grommets. Just enough to hush the mac, although potentially not enough airflow for a fully loaded system. You can laugh at my exploits in these Qiks:

Part I – wind noise:

Part Ib – going in:

Part II – getting it out:

Part III, the result:

Home Hacking

No, not breaking into them! Automating them and reducing the power that they use…

Current Cost Meter

Continue Reading…

Social Media Camp London 08

I spent Saturday at Social Media Camp London, and a mighty fine day it was too. A remarkable number of the folks there were SMC first-timers, with just a handful of the old guard. Good to have new blood into the game!

I haven’t see a complete round up of the talks (there were a lot!). The venue (Wallspace, St. Pancras) was absolutely stunning, the food delightful and Vero’s organization seamless.
I’ll write up my presentation on FOAF and Dunbar’s number (’6 degrees of seperation now 3′) and get it up on slideshare (to join this lot) just as soon as I’ve caught my breath. In the mean time there’s a nice mention here  (thanks @edent!). Continue Reading…