This is my attempt to build a small home based energy logger. It is not unique but has an RF12 on board so it can integrate with other systems, and it logs data to a OpenLog unit. This makes changing SD cards and logging a breeze It is based on OpenEnergyMonitor Many of these projects have been done all around the world. I think what makes this one unique is the fact that the sensor unit (the arduino with the CT) has a RF12 radio built in and also an Openlog unit from Sparkfun. The OpenLog unit is connected to the UART of the sensor unit. Full control off the Openlog can be obtained via the remote unit connected via RF12 radio.This means that the sensor unit can keep on logging to the Openlog. You can remotely initiate a session with the Openlog from the base station, and make changes to the settings, before putting it back in logging mode.