An Arduino Nano controls two relays which in turn can turn the car on, start it, and turn it off. Instead of adding a button for “push to start” he opted for a 13.56MHz RFID module.

inspiring [James] to design a completely new module based on an Arduino Nano. Hooking it up to the Psion’s data bus was a simple matter of wiring up the eight data lines to the Nano’s GPIO ports.