rotary-encoder.c

void setup() {
 pinMode(13, OUTPUT);
 Serial.begin(9600);
}

int lasta=0, lastb=0;
int dira=0, dirb=0;
int peaka=346, peakb=349;
int position = 0;
int cycle = 0;

void loop() {
  digitalWrite(13, HIGH);
  
  int currenta = analogRead(0);
  int currentb = analogRead(1);
  
  if (currenta == lasta || currentb == lastb) {
    return; 
  }
  
  //Serial.print(currenta);
  //Serial.print(" - ");
  //Serial.println(currentb);
  
  if (currenta > currentb) {
    if (currenta == peaka) {
      // CW
      if (currentb > lastb) {
        position++;
      // CCW
      } else if (currentb < lastb) {
        position--;
      }     
    }
  } else if (currentb > currenta) {
    if (currentb == peakb) {
      // CW
      if (currenta < lasta) {
        position++;
      // CCW
      } else if (currenta > lasta) {
        position--;
      }     
    }
  }
  
  Serial.println(position);
  lasta = currenta;
  lastb = currentb;
  delay(20);
  
}