/* menyalahkan dan mematikan lampu LED dengan menggunakan 1 tombol
   by djukarna @ STKIP SURYA                                       
   
   https://djukarna4arduino.wordpress.com/2015/02/02/on-off-lampu-led-dengan-1-tombol/*/
   
char tombol = A0;
char led = 2;
char A = 0;
char B = 0;

void setup()
{
  pinMode(tombol, INPUT);
  pinMode(led, OUTPUT);
}

void loop()
{
 label:  A = digitalRead(tombol);
          delay(100);
          if(A == 0) {goto label;}
          if (A == 1)
          {
            if(B == 0 )
              {  digitalWrite(led,HIGH);
                 B = 1;}
            else
              { digitalWrite(led,LOW);
                B = 0;}
          }
}