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 #include <Servo.h>Servo s1;

int sensorPin = 2;
int greenLED = 5;
int redLED = 6;

int doorOpenAngle = 90;

int doorCloseAngle = 0;

void setup() {
  Serial.begin(9600); 

  pinMode(sensorPin, INPUT);
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT); 
  s1.attach(3);
  s1.write(doorCloseAngle);

// start closed
}

void loop() {
  int val = digitalRead(sensorPin); 
  Serial.println(val);  // IR detects object (usually LOW)
  if (val == LOW) {
    digitalWrite(greenLED, HIGH);
    digitalWrite(redLED, LOW);    openDoor();
  }
  else {
    digitalWrite(greenLED, LOW);
    digitalWrite(redLED, HIGH);    closeDoor();
  }

}

// Smooth opening
void openDoor() {
  for (int pos = 0; pos <= 90; pos++) {
    s1.write(pos);
    delay(10);
  }

  delay(2000); // keep door open
}

// Smooth closing
void closeDoor() {
  for (int pos = 90; pos >= 0; pos--) {
    s1.write(pos);
    delay(10);
  }
}