When the module detects the front obstacle signals, the green indicators light on the circuit board lights up, and at the same time, the OUT port continuously outputs. The distance of the module for 2-30cm, and the angles is 35. The distance can be adjusted by the potentiometer, and the potentiometer is adjusted clockwise to increase the distance. Adjust the potentiometer counterclockwise to reduce the distance. The Sensors actively detects reflection, so the reflectivity and shape of the targeted is the to the distance. The distance of black is the smallest and that of white is the largest. Small-area objects have small distances and large-area objects have large distances. The OUTput port can be directly connection with port of the single chip microcomputer, or it can directly drive a 5V. Connection mode: GND-GND. The comparator adopts LM393, which works stably. The module can be power by 3-5V power supply. When the power is turned on, the red power indicators lights up. With sensitivity knob, the distance can be adjusted according to the actual environmental requirements to adapt to different application scenario.