#include "DHT.h"  //DHT Bibliothek laden
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd_1(0x27,20,4);
 
#define DHTPIN 13  //Der Sensor wird an PIN 2 angeschlossen    
#define DHTTYPE DHT22    // Es handelt sich um den DHT22 Sensor

#define led 3
#define buzzer 5
 
float lastTemperature = NAN;
 
DHT temperatursensor(DHTPIN, DHTTYPE);  //Der Sensor wird ab jetzt mit „dht“ angesprochen
 
void setup() {
  Serial.begin(9600);
  temperatursensor.begin();
  lcd_1.init();
  lcd_1.backlight();
  lcd_1.setCursor(1, 0);
  lcd_1.print("Temperature: ");
  
  pinMode(led, OUTPUT);
  pinMode(buzzer, OUTPUT);
 
}
 
void printTemp(float temperature)
{
  lcd_1.setCursor(1,1);
  if (isnan(temperature)) {
    lcd_1.print("Error");
  } else {
    lcd_1.print(temperature);
    lcd_1.print(" \337C");
  }
}
 
void loop() {

  float temperatur = temperatursensor.readTemperature();
 
  if (temperatur != lastTemperature) {
    lcd_1.clear();
    lcd_1.setCursor(1, 0);
    lcd_1.print("Temperature: ");
    printTemp(temperatur);
    lastTemperature = temperatur;
  }
  if (temperatur >= 25.00){
    digitalWrite(led, HIGH);
    tone(buzzer, 200);
    delay(500);
    digitalWrite(led, LOW);
    noTone(buzzer);
    delay(200);
  }
  else {
    digitalWrite(led, LOW);
  }
  delay(1000);
}