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

int main() {

DDRA = 0xFF;  //put PORTA into output mode
PORTA = 0;  //set POATA to LOW

while(1) {
    _delay_ms(500);               //500 millisecond delay
    PORTA = PORTA | 0b10000000;   //writes a HIGH to pin 8 of PORTA
    PORTA = PORTA & ~0b01111111;  //writes a LOW to except pin 8 of PORTA                            
    _delay_ms(500); 
    PORTA = PORTA | 0b01000000;   //writes a HIGH to pin 7 of PORTA
    PORTA = PORTA & ~0b10111111;  //writes a LOW to except pin 7 of PORTA
    _delay_ms(500); 
    PORTA = PORTA | 0b00100000;   //writes a HIGH to pin 6 of PORTA
    PORTA = PORTA & ~0b11011111;  //writes a LOW to except pin 6 of PORTA
    _delay_ms(500); 
    PORTA = PORTA | 0b00010000;   //writes a HIGH to pin 5 of PORTA
    PORTA = PORTA & ~0b11101111;  //writes a LOW to except pin 5 of PORTA
    _delay_ms(500);
    PORTA = PORTA | 0b00001000;   //writes a HIGH to pin 4 of PORTA
    PORTA = PORTA & ~0b11110111;  //writes a LOW to except pin 4 of PORTA                            
    _delay_ms(500); 
    PORTA = PORTA | 0b00000100;   //writes a HIGH to pin 3 of PORTA
    PORTA = PORTA & ~0b11111011;  //writes a LOW to except pin 3 of PORTA
    _delay_ms(500); 
    PORTA = PORTA | 0b00000010;   //writes a HIGH to pin 2 of PORTA
    PORTA = PORTA & ~0b11111101;  //writes a LOW to except pin 2 of PORTA
    _delay_ms(500); 
    PORTA = PORTA | 0b00000001;   //writes a HIGH to pin 1 of PORTA
    PORTA = PORTA & ~0b11111110;  //writes a LOW to except pin 1 of PORTA
  }
return(1);
}