Finally got the 7 segment display I've been meaning to build for a while built, its great being able to see power usage without having to have the computer on and the big green digits are really nice and clear.
Here's a video of it in action with a bit on pachube and appspot at the end:
I using a MAX7221CNG driver chip with four 1" green digits, following the tutorial (a very good tutorial I may add!) on the arduino site by here:
Here's the arduino sketch I used in the above video:
and after playing about with ladyada's python code from tweet-a-watt Im now using python on the computer side.
Here's the python script that outputs values to terminal, a file, pachube and google appspot:
Feels like things are coming together :)
Ive got an asus rooter on order and an arduino ethernet board to play about with so hopefully will not need the computer to be on all the time for data logging soon. Id also like to have a look at enclosures for the display to make things look nice.