ITEM NAME:5V IR Obstacle Avoidance Tracking Sensor Infrared PCB Module Arduino Robot Z a.imagelink a:hover.imagelink {color:#174d96;.TCRT5000 sensors constantly emit infrared infrared emitting diodes, infrared rays emitted when reflected or not reflected but the intensity is not big enough, the infrared receiver has been in the off state, then the output of the module is low, indicating diode remains off state; when the object appeared to be detected in the detection range, the infrared rays are reflected back and of sufficient intensity, infrared receiver tube saturation, the output side module is high, indicator LED is lit.