int motorPin = 3;

int hiz = 0;

void setup()

{

pinMode(motorPin, OUTPUT);

}

void loop()

{

for(hiz = 0; hiz <= 255; hiz++)

{

analogWrite(motorPin,hiz);

delay(20);

}

for(hiz = 255; hiz>=0; hiz--)

{

analogWrite(motorPin,hiz);

delay(20);

}

}