display3

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


void main() {
    DDRB  = 0b00000000;
    PORTB = 0b00000001;
    DDRA  = 0b11111111;
    PORTA = 0b00000001;

    int dir = 1;
    int num = 0;
    while (1) {
        if (!(PINB & 0b00000001)) {
            dir *= -1;
        }
        PORTA = 1 << num;
        _delay_ms (100);
        num = (num + 1*dir + 8) % 8;
    }
}