// average.nqc

// sensors
#define BUTTON	SENSOR_1
#define EYE		SENSOR_2

// number of samples
#define N	3

// average needs to be global for display
int average = 0;


// this function waits for a press and
// release of the touch sensor

void wait_for_touch()
{
	until(BUTTON == 1);
	until(BUTTON == 0);
	PlaySound(SOUND_CLICK);
}


task main()
{
	int index;
	int current;
	int samples[N];
	int total = 0;
	
	// setup sensors and display
	SetSensor(BUTTON, SENSOR_TOUCH);
	SetSensor(EYE, SENSOR_LIGHT);
	SetUserDisplay(average, 1);

	// start with N samples
	for(index=0; index<N; ++index)
	{
		wait_for_touch();
		
		current = EYE;
		samples[index] = current;
		total += current;
	}
	
	PlaySound(SOUND_UP);

	index = 0;	
	while(true)
	{
		// compute the average
		average = total * 10 / N;

		// get new sample
		wait_for_touch();
		current = EYE;
		
		// replace sample
		total -= samples[index];
		total += current;
		samples[index] = current;
		
		// adjust index
		++index;
		if (index==N) index = 0;
	}
	
}