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• 
• filtered-signal-v2
• 

void setup() {
  pinMode(A0, INPUT);
  pinMode(A1, INPUT);
  pinMode(A2, INPUT);
 
  // Enable internal pull-up resistors
  digitalWrite(A0, HIGH);
  digitalWrite(A1, HIGH);
  digitalWrite(A2, HIGH);
 
  PCICR =  0b00000010; // 1. PCIE1: Pin Change Interrupt Enable 1
  PCMSK1 = 0b00000111; // Enable Pin Change Interrupt for A0, A1, A2
}
 
void loop() {
 
  // MAIN LOOP 
}
 
ISR (PCINT1_vect) {
 
// If interrupt is triggered by the button
  if (!digitalRead(A0)) {
 
    button = true;}
 
// Else if interrupt is triggered by encoder signals
  else {
 
    // Read A and B signals
    boolean A_val = digitalRead(A1);
    boolean B_val = digitalRead(A2);
 
    // Record the A and B signals in seperate sequences
    seqA <<= 1;
    seqA |= A_val;
 
    seqB <<= 1;
    seqB |= B_val;
 
    // Mask the MSB four bits
    seqA &= 0b00001111;
    seqB &= 0b00001111;
 
    // Compare the recorded sequence with the expected sequence
    if (seqA == 0b00001001 && seqB == 0b00000011) {
      cnt1++;
      left = true;
      }
 
    if (seqA == 0b00000011 && seqB == 0b00001001) {
      cnt2++;
      right = true;
      }
  }
 
}

• Rotary Encoder Module with Arduino