#include <Servo.h> //library servo
#include <DHT.h>//library dht
#include <LiquidCrystal_I2C.h> //library lcd

#define TRIG_PIN 9      // Digital pin connected to the trigger pin of HC-SR04 sensor
#define ECHO_PIN 10     // Digital pin connected to the echo pin of HC-SR04 sensor
#define DHT_PIN 7       // Digital pin connected to the DHT22 sensor
#define DHTTYPE DHT22   // DHT 22 (AM2302) sensor type
#define BUZZER_PIN 6    // Digital pin connected to the buzzer

Servo myservo;///Create a servo object to control the servo motor
DHT dht(DHT_PIN, DHTTYPE); // Create a DHT object to read data from the DHT22 sensor
LiquidCrystal_I2C LCD(0x27, 16, 2); /* Create an LCD object using the I2C address 0x27, 
with 16 columns and 2 rows*/

long duration, distance; // variable ultrasonik
float temperature, humidity; // variabel DHT22

void setup() {
  Serial.begin(9600);//memulai  komunikasi serial dengan baud rate 9600
  pinMode(TRIG_PIN, OUTPUT); 
  pinMode(ECHO_PIN, INPUT);
  myservo.attach(5); // Attach the servo to the specified pin
  dht.begin(); //inisialisasi dht
  LCD.init(); //inisialisasi lcd
  LCD.backlight(); // Turn on the backlight for the LCD
  pinMode(BUZZER_PIN, OUTPUT); 
}

void loop() {
  //pembacaan sensor ultrasonik di serial monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = (duration / 2) / 29.1; 
  /*The value 29.1 is derived from the speed of sound in air 
  (approximately 343 meters per second or 34300 centimeters per second) 
  divided by 2 (for one-way travel) and then converted from microseconds to centimeters.*/

//pembacaan sensor dht
  temperature = dht.readTemperature();
  humidity = dht.readHumidity();

//display lcd
  LCD.clear();
  LCD.setCursor(0,0);//letak di kolom 0, baris 0
  LCD.print("T=");
  LCD.print(int(temperature)); LCD.print(char(223)); LCD.print('C'); 
  LCD.setCursor(8,0); // letak di kolom 8, baris 0
  LCD.print(" H="); 
  LCD.print(int(humidity)); LCD.print(char(37));
  delay(50);

  // Check proximity
  if (distance < 20) {
  // If an object is close, activate the buzzer and move the servo to 90 degrees
    tone(BUZZER_PIN, 1000);
    tone(BUZZER_PIN, 1000);
    myservo.write(90);
    LCD.setCursor(0,1);
    LCD.print("ada yang dekat");
  } 
  else {
  //// If no object is close, turn off the buzzer and move the servo to 0 degrees
    myservo.write(0);   // Return the servo to its initial position
    noTone(BUZZER_PIN);
    LCD.setCursor(0,1);
    LCD.print("semua jauh");
    
  }
  delay(1000);//// Delay for 1 second before repeating the loop
}