#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup() {
  // Display initialisieren
  lcd.init();                       // initialize the lcd 
                                    // Print a message to the LCD.
  lcd.backlight();
  lcd.print("Hello, world!");

  // Serielle Schnittstelle initialisieren
  Serial.begin(9600);
}

void loop() {
  if (Serial.available()) {
    delay(100);
    lcd.clear();
    while (Serial.available() > 0) {
      lcd.write(Serial.read());
    }
  }
}