This photo electric counter uses a groove IR Optocoupler to detect if there is anything between the IR emiter and IR receiver. With this method, this module can detect the number of obstruction in a given time thus to detect the speed of the rotation. When the opto sensor didn't covered , the D0 output logic LOW, the signal indicate LED light, when the opto sensor covered, the D0 output logic HIGH and the LED off, adjust the potentiometer can adjust the sensitivity of the sensor. And we add a Crowtail interface to it, so we can use with a Crowduino to make our work more easier and convenient.
Working votage: 3V3 - 5V
LM393 Comparator to make the output signal easy to read
Nothing detected: Output low, LED on; Obstruction between the emitter and receiver: Output high, LED off.