TCRT5000 sensor and the working principle of a general infrared sensor, as a transfer of a sense .TCRT5000 having an infrared transmitter and an infrared receiver tube when the emission of the infrared signal is received by the reflective tube and the received will change the resistance of the tube in the form of voltage changes in the circuit are generally reflected out, and after the ADC conversion circuit such as plastic or LM324 output result obtained after the treatment. taken from the resistance change in the intensity of the infrared signal received by the receiving tube, often show the reflecting surface . the color and the reflective surface of the distance between the receiver tube hardware reference schematics two aspects as follows: