pastamakaroni

#include <avr/io.h>
#include <avr/delay.h>
int main (void) {
DDRB=0b11111111;
DDRA=0b00001111;
PORTA=0b11111111;
PORTB=0b00000000;
while(1) {
PORTA=0b11111110;
_delay_ms(1);
if(bit_is_clear(PINA,4)){
    PORTB=0b00000001;
}
if(bit_is_clear(PINA,5)){
    PORTB=0b00000010;
}
if(bit_is_clear(PINA,6)){
    PORTB=0b00000100;
}
if(bit_is_clear(PINA,7)){
    PORTB=0b00001000;
}
PORTA=0b11111101;
_delay_ms(1);
if(bit_is_clear(PINA,4)){
    PORTB=0b00010000;
}
if(bit_is_clear(PINA,5)){
    PORTB=0b00100000;
}
if(bit_is_clear(PINA,6)){
    PORTB=0b01000000;
}
if(bit_is_clear(PINA,7)){
    PORTB=0b10000000;;
}
}
}