constexpr uint8_t LEDblau {6};
constexpr uint8_t taster {2};

void setup() {
  pinMode(LEDblau, OUTPUT);
  pinMode(taster, INPUT_PULLUP);     
}
void loop() {
  if (!digitalRead(taster))  {
    digitalWrite(LEDblau, HIGH);
    delay(1000);
    digitalWrite(LEDblau, LOW);
    delay(1000);
  } else {
    digitalWrite(LEDblau, LOW);
  }
}