#include <avr/io.h>

void setup() {
  // put your setup code here, to run once:
  PORTA.DIRSET=0xff;
 
}

void loop() {
  PORTA.OUT=0b01000000; 
  delay(500);
  PORTA.OUT=0b00000000;
  delay(500);
  // put your main code here, to run repeatedly:

}