void setup() {
  // put your setup code here, to run once:
  volatile char *dirf;
  volatile char *outf;
  dirf=0x30;
  outf = 0x31;
  *dirf=0xFF;
  while(1){
    *outf = 0xFF; //by using portf data register the 7 segment leds controlled
  }
}

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