This project combines electronics, magnetics, optoelectronics and pneumatics to create an automatic opening door, <nerd>like on Star Trek</nerd>.
Behind the scenes, the components used are a 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 3 modes:
- Open(opens the door, stays open)
- Close(closes the door, stays closed)
- Auto(closes the door but opens/closes automatically).
Challenges included getting the right parts for the pneumatic connectors and filtering noise over an 18m stretch of cable for the IR sensors. The source code shows some quite aggressive filtering of output from the sensors, as well as some confusing logic to make sure that the door doesn’t close on you or open at the wrong time.