F249 4 PIN Infrared Speed Sensor Module For Arduino 51 -AVR -PIC 3.3V-5V High Quality

Description   High Quality 4 PIN Infrared Speed Sensor Module Module Description 1. Working voltage: 3.3–5.5V 2. The use of imported groove coupler sensor, the groove width of 5mm. 3. The sensor slots are blocked, the output high and the light is off; no shelter, output low and lights. 4. Output form: Digital switching output (0 and 1) 5. Using LM393 comparator output, type clean, good waveform, driving ability over 15mA. 6. A fixed bolt hole for easy mounting. Module interface specification (3-wire) 1 VCC 3.3V-5V external 2 GND External GND 3 DO small board digital output interface switch connected to the microcontroller IO port 4.AO: Invalid