The part list consists of one Arduino, two resistors, and one IR emitter. That’s right, an emitter. When an LED (IR or otherwise) is reverse biased it can act as a light sensor.

Electronic enthusiasts may be interested in a new open source infrared sensor which has been created to support both Raspberry Pi and Arduino powered projects. The IR Detector proximity sensor has ...

When the Pi is shut down in software, the Arduino can sense that the Pi isn’t on any more and disconnect the power. The remote control is used to turn the Pi on.