MIT Researcher Valentin Heun created the RFID door opener as he was annoyed that he needed both his MIT ID card and a key to gain access to the MIT Media Lab. With this system his RFID-embedded ID card is read by an RFID evaluation shield connected to an Arduino Uno board. His RFID code is approved and a servo opens the door. A laser cut mounting board allows the servo and RFID evaluation shield to be attached to the door’s handle and deadbolt.
The code can be taken from here.
[original story: Arduino Blog]