Side-looking Infrared Emitters and IR Detectors. These simple devices operate at 940nm and work well for generic IR systems including remote control and touch-less object sensing.

Using a simple ADC on any microcontroller will allow variable readings to be collected from the detector. The emitter is driven up to 50mA with a current limiting resistor as with any LED device. The detect is a NPN transistor that is biased by incoming IR light.