The infrared emitting diode of the TCRT5000 sensor continuously emits infrared rays. When the emitted infrared rays are not reflected back or reflected back but the intensity is not large enough, the infrared receiving tube is always in the off state, and the output end of the module is at a high level, indicating The diode is always off; when the detected object appears in the detection range, the infrared light is reflected back and the intensity is large enough, and the infrared receiving tube is saturated. At this time, the output end of the module is low, indicating that the diode is illuminated. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Dadangjia