Strange behaviour using interrupts

Projects Programming
12

New code. Now the ISR only toggles a var. Still does not work.

static const int INTERRUPT_NUMBER = 0;
static const int INTERRUPT_MODE = LOW;
static int mustBeep = 0;

void setup() {
  attachInterrupt(INTERRUPT_NUMBER, requestBeep, INTERRUPT_MODE);
}

void loop() {  
  if(mustBeep){
    mustBeep = 0;
    beep();
  }
}

void beep(){
  noTone(7);
  tone(7, 440, 1000);
}

//ISR. Must take no parameters and return nothing.
void requestBeep(){
  mustBeep = 1;
}