Wiring the VCU
One of the most important parts of the Fig-Leaf is the vehicle control unit (VCU). This board communicates with the inverter in the same way the Leaf would. A number of options exist, including purpose built inverters with the VCU built in.
For the Fig Leaf we are using Damien Maguire's Leaf VCU. This board can be programmed in the same way as an Arduino and even has a Wi-Fi interface. The VCU takes inputs from the throttle pedal, the ignition switch, some sensors and the car's 12 volt battery. It sends signals to power up the inverter and the inverter responds by telling the VCU what the state of the motor and battery is.