A gem to provide a Ruby interface to the CurrentCost energy meter (

Licensed under the MIT license (See COPYING file for details)

Author: James Smith ([email protected] /




1) Enable gems from gemcutter, if you haven't already done so:

> sudo gem install gemcutter
> sudo gem tumble

2) Install gem

> sudo gem install currentcost


rb232 >= 0.2.3


You can read data from the meter by creating an instance of the CurrentCost::Meter class, and registering an observer which will receive readings. See examples/simple.rb or the CurrentCost::Meter documentation for a simple example of how to do this.


This gem includes the 'currentcost_tray_monitor.rb' application. This is a program which will sit in your system tray and display a coloured icon based on your power usage. To use the program, run:

currentcost_tray_monitor.rb -p your_serial_port_name

The program requires the Gtk2 libraries for Ruby (available from If the EEML gem ( is installed, it can also serve your power data over an HTTP connection to a system like Pachube (

For more details, see