Arduino TCRT5000 infrared reflectance sensorTCRT5000 sensors continuously emit infrared emitting diodes, infrared rays emitted when not being reflected back or reflected back but the strength is not big enough, the phototransistor has been in a shutdown state, then the output modules is high, indicating diode remains off state; when the object appeared to be detected within the detection range of the infrared is reflected back and the intensity is large enough, the phototransistor saturated, then the output of the module is low, indicating the diode is lit. 1 meter pulse data sampling2, fax paper shredders detection3, obstacle detection4, black and white line detection. Module Features: 1, using infrared reflective sensor TCRT50002, detecting the reflected distance: 1mm ~ 25mm applicable3, the comparator output signal clean, good waveform driving ability more than 15mA. 4, with multi-turn precision potentiometer adjustable sensitivity adjustment5, the working voltage of 3.3V-5V6, the output format: digital switching output (0 and 1)7, a fixed bolt holes for easy installation8 small plates PCB size: 3.2cm x 1.4cm9, using a wide voltage LM393 comparator.