The VCNL36687S is a low-power proximity sensor. It includes the emitter, detector, and all signal processing in a package that is 3 x 2 x 1 mm. The emitter is a VCSEL (vertical cavity surface-emitting laser) with a very narrow angle of emission of ±3°. As a digital sensor, it has lots of programming flexibility via an I²C interface. It is used to detect the presence of an object and can be used to determine if the object is moving towards or away from the sensor.