#include <Servo.h>

Servo myservo;        // create servo object to control a servo
int encoderPinCLK = 2; // connect KY-040 CLK to digital pin 2
int encoderPinDT = 3;  // connect KY-040 DT to digital pin 3
int encoderSwitch = 4; // connect KY-040 SW to digital pin 4
int val;               // variable to read the encoder state
int encoderPos = 512;  // variable to store the encoder position

void setup() {
  myservo.attach(9);      // attaches the servo on pin 9 to the servo object
  pinMode(encoderPinCLK, INPUT);
  pinMode(encoderPinDT, INPUT);
  pinMode(encoderSwitch, INPUT_PULLUP); // Internal pull-up resistor for the switch
  attachInterrupt(digitalPinToInterrupt(encoderPinCLK), updateEncoder, CHANGE);
}

void loop() {
  // Use the encoder position directly or scale it as needed
  val = map(encoderPos, 0, 1023, 0, 180);
  myservo.write(val);
  delay(15);
  
  // Check the switch state
  if (digitalRead(encoderSwitch) == LOW) {
    // Reset to center position
    encoderPos = 512;
  }
}

void updateEncoder() {
  int CLKstate = digitalRead(encoderPinCLK);
  int DTstate = digitalRead(encoderPinDT);

  if (CLKstate != DTstate) {
    encoderPos++;
  } else {
    encoderPos--;
  }
}