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



// Set up GPIO here
void pin_setup() {
    DDRB |= (1 << DDB3);
}


int main() {
    pin_setup();

    while (1) {
        PORTB ^= (1 << PORTB3);
        _delay_ms(500);
    }
    
}