#include <LiquidCrystal_I2C.h>
#include <DHT.h>

#define DHTPIN 8
#define DHTTYPE DHT22
#define BUZZER_PIN 7

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()
{
  Serial.begin(9600);
  Serial.println("Temperature Monitoring System");
  lcd.begin(16, 2);
  lcd.backlight();
  dht.begin();

  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);
}

void loop() {
  float t = dht.readTemperature();
  float h = dht.readHumidity();
  delay(1000);

  //Displays on LCD
  lcd.setCursor(0, 0);
  lcd.println("Temp="); lcd.print(t); lcd.println("C");
  lcd.setCursor(0, 1);
  lcd.println("Humidity="); lcd.print(h); lcd.println("%");

  //Control condition  (If temperature > 30°C, turn on buzzer)
  if (t > 30) {
    digitalWrite(BUZZER_PIN, HIGH);// Turn ON buzzer
    lcd.setCursor(14, 0);
    lcd.print("!!");  
    Serial.println("High Temperature!"); // Serial alert

  } else {
    digitalWrite(BUZZER_PIN, LOW);  // Turn OFF buzzer
    lcd.setCursor(14, 0);
    lcd.print("  ");   

  }

  //Display on serial monitor screen
  Serial.println("Temp= "); Serial.print(t); Serial.println(" C");
  Serial.println("Humidity= "); Serial.print(h); Serial.println(" %");

}