#define ENC_CLK 4
#define ENC_DT 2
#define LED 5
int counter = 0;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  
  // setup pins
  pinMode(ENC_CLK, INPUT);
  pinMode(ENC_DT, INPUT);
  pinMode(LED, OUTPUT);

  // adding interrupt feature
  attachInterrupt(digitalPinToInterrupt(ENC_CLK), readEncValue, FALLING);
}

// interrupt service routine
void readEncValue() {
  int dtValue = digitalRead(ENC_DT);
  
  if (dtValue == HIGH) {
    digitalWrite(LED, HIGH);
    counter++;
    Serial.print("Movement is in clockwise direction");
    Serial.println(counter);
  }
  if (dtValue == LOW) {
    digitalWrite(LED, LOW);
    counter--;
    Serial.print("Movement is in counter clockwise direction");
    Serial.println(counter);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}