This module is a smart car speed module ! Groove on the radio using photovoltaics, as long as the non- transparent objects can be triggered via Groove ( with shop car yards disk to use ) ! Output 5V TTL level . Pulses with Schmitt trigger debounce , very stable, can be used to measure speed of the car , the measured distance, etc. Application !
Four pin is defined as +5 GND OUT1 OUT2 OUT1 OUT2 which is level output ! Direct access to the microcontroller IO port , each way with an LED indicates the output status