Problems using serial port

Projects Programming
3

Thanks for your fast reply. I have my code not here yet, but I used to retype my test-code:

void setup() {
  Serial.begin(9600);
  Serial1.begin(9600);
  pinMode(21, OUTPUT);
  digitalWrite(21, HIGH);
}

int Daten;

void loop() {
  Daten=Serial1.read();
  Serial.println(Daten);
  delay(2000);
}