void setup() {
  // put your setup code here, to run once:

volatile char *dirf,*dirk ,*dira,x;
volatile char *outf,*ink, *outa;

dirf=0x30; dira=0x21; dirk=0x107;
outf=0x31; ink=0x106;outa=0x22;
*outf=0x0F ; *dirk=0x00;*dira=0x0F;



while(1){
  for(int i=0 ;i<4;i++){
    *outf=1 <<i;
    *outa=*ink;
  }
}
}
void loop() {
  // put your main code here, to run repeatedly:

}