#include <DHTesp.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <ESP32Servo.h>

#define DHT_PIN    4
#define TRIG_PIN   5
#define ECHO_PIN   18
#define SERVO_PIN  19

DHTesp dhtSensor;
LiquidCrystal_I2C lcd(0x27, 16, 2);
Servo myServo;

// Hàm đọc khoảng cách
float readDistanceCM() {

  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 30000);

  float distance = duration * 0.0343 / 2;

  return distance;
}

void setup() {

  Serial.begin(115200);

  // DHT22
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  // LCD
  lcd.init();
  lcd.backlight();

  // HC-SR04
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // Servo
  myServo.attach(SERVO_PIN);
  myServo.write(0);

  // Hiển thị ban đầu
  lcd.setCursor(0, 0);
  lcd.print("CHAO MUNG");
  
  lcd.setCursor(0, 1);
  lcd.print("CHU NHAN");
}

void loop() {

  TempAndHumidity data = dhtSensor.getTempAndHumidity();

  float temperature = data.temperature;
  float distance = readDistanceCM();

  Serial.print("Nhiet do: ");
  Serial.println(temperature);

  Serial.print("Khoang cach: ");
  Serial.println(distance);

  // Điều kiện mở cửa
  if (temperature > 37 && distance < 20) {

    // Mở cửa
    myServo.write(90);

  } else {

    // Đóng cửa
    myServo.write(0);
  }

  delay(1000);
}