Blink

#include <avr/io.h>
#include <util/delay.h>


int main(void)
{
 DDRD = 0xff;
 PORTD = 0x00;
   while (1)
   {
       for (int i=0; i<=2; i++)
       {
           PORTD |= (1<<i);
           _delay_ms(100);
           PORTD &= ~(1<<i);
           _delay_ms(100);

       }
   }
}