void setup() {
  // put your setup code here, to run once:
  volatile char *ddirF, *outF, *outputK, *ddirK;
  volatile long i;
  ddirF = 0x30; outF = 0x31; ddirK = 0x107; outputK = 0x108;

  *ddirF = 0x03;  
  *ddirK = 0x03;

  while (1) {
    *outputK = 0x02;
    *outF = 0x01;
    for (i = 0; i < 50000; i++);

    *outputK = 0x01;
    *outF = 0x01;
    for (i = 0; i < 50000; i++);

    *outputK = 0x02;
    *outF = 0x02;
    for (i = 0; i < 50000; i++);

    *outputK = 0x01;
    *outF = 0x02;
    for (i = 0; i < 50000; i++);
  }
}

void loop() {
  // put your main code here, to run repeatedly:

}