The sensor module has a strong adaptability to environmental light, it has a pair of infrared transmitter and receiver tubes, the transmitter tube emits a certain frequency of infrared light, when the detection direction encounters an obstacle (reflective surface), infrared reflection back to be received by the receiver tube, after the comparator circuit processing, the green indicator will be lit up, at the same time, the signal output interface outputs a digital signal (a low-level signal), can be adjusted by potentiometer knob detection distance range of 2 to 30cm. The detection distance can be adjusted by potentiometer knob, the effective distance range of 2 ~ 30cm, the working voltage of 3.3V-5V. the sensor detection distance can be adjusted by the potentiometer, has the characteristics of small interference, easy to assemble, easy to use, etc., it can be widely used in robots, obstacle avoidance, obstacle avoidance trolleys, assembly line counting, and black-and-white line trajectory and so on many occasions. 1 VCC external 3.3V-5V voltage (can be directly connected to 5v microcontroller and 3.3v microcontroller);2 GND External GND;3 OUT Small board digital output interface (0 and 1)