Based on the OpenEVSE project
Arduino Electric Vehicle Charging Station "Electric Vehicle Supply Equipment" (EVSE) implementing the J1772 protocol.
J1772 is used in the current generation of Electric Vehicles and Plug ins such as the Nissan LEAF and Chevy Volt.
The EVSE advertises the Maximum current available to the EV with a 1khz pilot signal. The Duty Cycle of the pilot sets the available current the EV may draw. The EVSE also functions as a safety device, the 240V AC lines of the J1772 plug are not hot until the EVSE and EV command the start of charging. The EVSE also functions as A ground fault interrupt device (GFCI).
Parts list and Schematics are attached as images.