#define ECHO_PIN 3
#define TRIG_PIN 2
#define BUZZ_PIN 5
#define LED_PIN 7
#define PIR_PIN 1

#include <Servo.h>

Servo myServo;

int potpin = 0;
int val = 0;

float readDistanceCM(){
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, HIGH);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(PIR_PIN, INPUT);
  Serial.begin(115200);
  pinMode(BUZZ_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  myServo.attach(9);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println(readDistanceCM());
  int distance = readDistanceCM();
  val = digitalRead(PIR_PIN);
  if (distance < 100 && val == LOW){ //Servo akan membuka pintu apabila objek terdeteksi pada jarak kurang dari 100 cm
    myServo.write(0);
    tone(BUZZ_PIN, 100);
    digitalWrite(LED_PIN, LOW);
    delay(200);
  } else if (distance > 100 && val == HIGH){ //Servo akan menutup pintu apabila jarak objek lebih dari 100 cm,
  //dan akan menyalakan lampu apabila terdeteksi oleh sensor PIR.
    myServo.write(90);
    noTone(BUZZ_PIN);
    digitalWrite(LED_PIN, HIGH);
    delay(250);
  } else if (val == HIGH){ // LED akan tetap menyala selama ada orang di dalam. 
    myServo.write(90);
    noTone(BUZZ_PIN);
    digitalWrite(LED_PIN, HIGH);
    delay(250);
  }else { // Lampu led akan mati, dan pintu akan menutup apabila tidak ada orang pada ruangan. 
    myServo.write(90);
    noTone(BUZZ_PIN);
    digitalWrite(LED_PIN, LOW);
    delay(250);
  }
}