void setup() {
  // put your setup code here, to run once:
  volatile long i, j;

  volatile char *dirf, *dirk, x;

  volatile char * outf, *ink;

  dirf = 0x30;  dirk = 0x107;

  outf = 0x31;  ink = 0x106 ;

  *dirf = 0x01;  *dirk = 0x00;

  i = 0;
  while (1) {
    x = *ink;
    if ((x & 0x01) == 0x01) {
      i++;
      for (j = 0; j < 1; j++);
    }
    if (i % 2)
      *outf = 0x02;
    else
      *outf = 0x01;
  }
}
void loop() {

  // put your main code here, to run repeatedly:

}