This project combines electronics, magnetics, optoelectronics and pneumatics to create an automatic opening door, like on Star Trek. Behind the scenes, the components used are an Arduino Uno, a HMC5883L magnetometer, a couple of Sharp IR sensors, a couple of cheapo pneumatic valves, a 1m long actuator/piston, a Bambi BB8 silent compressor and a load of wires/pneumatic connectors.
The door operates in two modes – automatic, where the IR sensors detect approach and open the door, and manual, where a magnetic "key" triggers the door via the magnetometer.
The silent compressor ensures the whole thing runs quietly enough for domestic use, and the pneumatic actuator gives a smooth, controlled motion that feels suitably futuristic.