const int ledRed = 6;
const int ledBlue = 7;
const int ledGreen = 8;
void setup() 
{
//pinMode(ledRed, OUTPUT);       // pinMode aud Output setzen
pinMode(ledBlue, OUTPUT);
pinMode(ledGreen, OUTPUT);
}

void loop() 
{
//digitalWrite(ledRed, HIGH); // LED einschalten
digitalWrite(ledBlue, LOW);
digitalWrite(ledGreen, HIGH);
delay(500);                   //300ms warten 
//digitalWrite(ledRed, LOW);    //LED ausschalten
digitalWrite(ledBlue, HIGH);
digitalWrite(ledGreen, LOW) ;
delay(500);                   //300ms warten

}