If won't trigger inside while

Question

currently I'm trying my best at programming a microcontroller.

int main()
{
    init_ports();

    while(1){
        if(gameStatus == 1){
            gameStatus = 2;
            beep(120);
        }
    }
}

is my main, gameStatus is a global uint_8. It gets set by an interrupt that is caused by pressing a button.

ISR(INT0_vect){
    if(gameStatus == 0)
        gameStatus = 1; // that works

}

The main however won't recognize gameStatus at all. Is there a reason why this could be?

Thanks!

make sure the interrupt is actually being run, and it sets gameStatus to 1 — Neil Locketz, Dec 07 '16 at 19:41
When you say it will not recognise `gameStatus`, does it fail to compile? A possibility is that you have a global initialised to zero (default) and it is not getting set to 1 for some reason. — cdarke, Dec 07 '16 at 19:43
and what does the ISR do when `gameStatus == 2` as set in `main`? What does "not recognize" mean? That it does not compile? — Weather Vane, Dec 07 '16 at 19:43

score 2 · Accepted Answer · answered Dec 07 '16 at 19:55

2

Thanks to wildplasser!

Changing

uint8_t gameStatus = 0;

into

volatile uint8_t gameStatus = 0;

did the trick.

answered Dec 07 '16 at 19:55

3jfx

1 Answers1