// battery.nqc

#define BATT SENSOR_1

task main()
{
    int b;
    SetSensorType(BATT, SENSOR_TYPE_NONE);

    b = abs(BATT - 512);

    // treat > 1.75V as 0V
    if (b > 179)
        b = 0;

    if (b < 128)
        PlaySound(SOUND_LOW_BEEP);
    else if (b < 154)
        PlaySound(SOUND_DOUBLE_BEEP);
    else
        PlaySound(SOUND_UP);    
}