Velocidad motor DC

int MOTOR=6;
	int i;
	void setup(){
	pinMode(MOTOR, OUTPUT);
	Serial.begin(9600);
	analogWrite(MOTOR, 0);
	}
	void loop(){
	for(i=0; i<=255; i++){
	analogWrite(MOTOR, i);
	Serial.println(i);
	delay(500);
	}
	for(i=255; i>=0; i--){
	analogWrite(MOTOR, i);
	Serial.println(i);
	delay(500);
	}
	}