Infrared Sensor Module has built-in IR transmitter and IR receiver that sends out IR rays and looks for reflected IR rays to detect presence of any obstacle in front of the sensor module. The module has on board potentiometer that lets user adjust detection range. The sensor has very good and stable response even in ambient light or in complete darkness. It is Arduino and Rasberry Pi compatible board. More here: https://www.indiamart.com/proddetail/ir-sensor-module-for-arduino-rasberry-pi-16016512830.html Have fun!!