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.

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.

Vishay’s VCNL4100 is an IR proximity sensor that works up to 1m, and includes an ambient light sensor. Inside, it combines an infra-red (940nm) emitter, photo detectors for proximity and ambient light ...