After a bit of work, I've finally got my CurrentCost meter working in Ruby, and I now have a power monitor sitting in my system tray! There were a few stages involved…
Serial comms: The ruby-serialport library that already existed for Ruby was no good to me. Firstly, it didn't seem to be in a working state, but more importantly, the license it is under (GPL) is no good to me. So, I had to write my own. I've created a nice simple serial library (including a gem) for Ruby called RB232, which is available on GitHub. It only supports reading at the moment, and only works on Linux systems, but it's a start. Next!
Reading CurrentCost data: Once RB232 was in place, this was pretty easy. Just create a couple of classes to wrap up the process of getting data from the meter, and away you go. Easy. Also released as a Ruby gem on Github.
User interface: Last step was to make a simple user interface for the meter; it's a simple tray icon that changes colour based on power usage. It's based heavily on another very useful tool called cctrayrb, so many thanks to Daniel Parnell for doing the heavy GUI lifting there. The app is included as part of the currentcost-ruby gem mentioned above.
Anyway, it's all freely available, so if you have a CurrentCost meter and a serial cable for it, you can grab the code and get going. Enjoy :)