#define DELAY 100000
void setup() {
  // put your setup code here, to run once:
   volatile char *dirf,*dirk;
   dirf = 0x30; dirk = 0x107;
   *dirf = 0x03; 
   *dirk = 0x03;
}

void loop() {
      volatile char *outf,*outk;
      outf = 0x31; outk = 0x108;
      volatile long i;
  // put your main code here, to run repeatedly:
      *outk = 0x02;
      *outf = 0x01;
      for(i=0; i<DELAY;i++);
      *outk = 0x01;
      *outf = 0x01;
      for(i=0; i<DELAY;i++);
      *outk = 0x02;
      *outf = 0x02;
      for(i=0; i<DELAY;i++);
      *outk = 0x01;
      *outf = 0x02;
      for(i=0; i<DELAY;i++);
}