// Rotary Encoder Inputs
#define CLK 2 // Output A
#define DT 3 // Output B

volatile int counter = 0;
int lastStateCLK;
String currentDir = "";

void setup() 
{
  // Set encoder pins as inputs
  pinMode(CLK, INPUT);
  pinMode(DT, INPUT);

  // Setup Serial Monitor
  Serial.begin(9600);

  // Read the initial state of CLK
  lastStateCLK = digitalRead(CLK);

  // Attach interrupts to the CLK and DT pins
  attachInterrupt(digitalPinToInterrupt(CLK), updateEncoder, CHANGE);
  attachInterrupt(digitalPinToInterrupt(DT), updateEncoder, CHANGE);
}

void loop() 
{
  // Display the counter and direction
  Serial.print("Direction: ");
  Serial.print(currentDir);
  Serial.print(" | Counter: ");
  Serial.println(counter);

  delay(100); // Small delay to avoid overwhelming the serial output
}

void updateEncoder() 
{
  // Read the current state of CLK
  int currentStateCLK = digitalRead(CLK);

  // If last and current state of CLK are different, then pulse occurred
  if (currentStateCLK != lastStateCLK) 
  {
    // If the DT state is different than the CLK state then
    // the encoder is rotating CCW so decrement
    if (digitalRead(DT) != currentStateCLK) {
      counter--;
      currentDir = "CCW";
    } else {
      // Encoder is rotating CW so increment
      counter++;
      currentDir = "CW";
    }

    // Remember last CLK state
    lastStateCLK = currentStateCLK;
  }
}