#include <LiquidCrystal_I2C.h>
#include "DHT.h"
#define DHTPIN 2
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27,20,4);

void setup() {
  Serial.begin(9600);
  Serial.println("DHT22 Testprogramm");
  dht.begin();
}

void loop() {
  delay(2000);
  float h = dht.readHumidity();
  float t = dht.readTemperature();

lcd.init();
lcd.backlight();
lcd.setCursor(0, 0);
lcd.print("Humidity:    ");
lcd.print(h);
lcd.println("%");

lcd.setCursor(0,1);
lcd.print("Temperatur:  ");
lcd.print(t);
lcd.println("C");

if (isnan(h) || isnan(t)) {
  lcd.setCursor(0,0);
  lcd.println("                ");
  lcd.setCursor(0,1);
  lcd.println("      Fehler!    ");
  return;

}




Serial.print("Humidity: ");
Serial.print(h);
Serial.print("%\t");
Serial.print("Temperatur: ");
Serial.print(t);
Serial.println("C");
}