// galvanic.nqc

#define GALV SENSOR_1
#define DURATION 500
#define DELAY 300

task main()
{
    int new, old;

    SetSensorType(GALV, SENSOR_TYPE_NONE);

    old = GALV;

    while(true)
    {
        new = GALV;
        if (new > old)
            PlayTone(55, DURATION); // lower stress
        else if (new < old)
            PlayTone(220, DURATION); // higher stress
        else
            PlayTone(110, DURATION); // same stress

        old = new;
        Wait(DELAY);
    }
}