nfrared obstacle avoidance sensor is equipped with distance adjustment function and is especially designed for wheeled robots. This sensor has strong adaptability to ambient light and is of high precision. It has a pair of infrared transmitting and receiving tube. When infrared ray launched by the transmitting tube encounters an obstacle (its reflector), the infrared ray is reflected to the receiving tube, and the indicator will light up; the signal output interface outputs digital signal. We can adjust the detection distance through the potentiometer knob ( effective distance: 2~40cm, working Voltage: 3.3V-5V ). Thanks to a wide voltage range, this sensor can work steadily even under fluctuating power supply voltage and is suitable for the use of various micro-controllers, Aduino controllers and BS2 controllers. A robot mounted with the sensor can sense changes in the environment.