void setup() 
{
  volatile long i,j;
  volatile char *dirf, *dirk, *dira, *dirc;
  volatile char *outf, *ink, *outa, *outc;
  dirf=0x30; dirk=0x107; dira=0x21; dirc=0x27;
  outf=0x31; ink=0x106; outa=0x22; outc=0x28;
  *dirf=0x0f; 
  *dirk=0x00;
 // *dira=0x0f;
  

  while(1)
  {    
    for(i=0; i<4 ;i++)
    {
      *outf=1<<i;
      *outa= *ink;//columns
      if(*ink != 0)
      {
      *outc=1<<i;//rows
      // for(j=0; j<500000; j++);
      *outc=0;
      }
      
    }
  }


}

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

}