Description:

The rotary encoder module is an angular measuring device. It is used to precisely measure 24-steps rotation of knob that can turn infinitely (with no end stop like a potentiometer has). The rotary encoder module also have a pushbutton when you press on the axis (like the ones used for navigation on many music controllers).

Arduino sketch:

 int val;  int encoder0PinA = 3;  int encoder0PinB = 4;  int encoder0Pos = 0;  int encoder0PinALast = LOW;  int n = LOW;  void setup() {    pinMode (encoder0PinA,INPUT);    pinMode (encoder0PinB,INPUT);    Serial.begin (9600);  }  void loop() {    n = digitalRead(encoder0PinA);    if ((encoder0PinALast == LOW) && (n == HIGH)) {      if (digitalRead(encoder0PinB) == LOW) {        encoder0Pos--;      } else {        encoder0Pos++;      }      Serial.print (encoder0Pos);      Serial.print ("/");    }    encoder0PinALast = n;  }