int LED= 7; 
int TASTER = 13; 
int TasterLesen; 

void setup()  
{ 
  pinMode(LED, OUTPUT); 
  pinMode(TASTER, INTPUT_PULLUP); 
} 

void loop() 
{ 
  TasterLesen = digitalRead(TASTER); 

  // Taster gedrueckt → LOW 
  if (TasterLesen == LOW)   
  { 
    digitalWrite(LED, HIGH) 
  } 
}