Massage machine

After completing the activity using the DC motor and potentiometer, I got the idea of making massage machine with the DC motor and the force sensor. The massage machine vibrates when I put pressure on the vibrating surface. The extent of vibration depends on how strongly I push the machine to body.
I started to extending the wires connected to a force sensor installed on the massage machine. I installed he DC motor inside the massage equipment. Although I wanted to use the Piezo Buzzer and enable it to play musice notes whenever massaging activity is going on, my Piezo Buzzer was broken (one wire came off). Then, I coded a program which takes input value from the force sensor and provide output through vibration of the DC motor. 
 
Components used:
1- Arduino Uno
1- Breadboard
2- 10Kohms resistor
1-Force sensor
1-diode
1-transistor
1-DC motor
Connecting wires
 
Arduino code:

/*

 * one pot fades one motor

 * modified version of AnalogInput

 * by DojoDave <http://www.0j0.org>

 * http://www.arduino.cc/en/Tutorial/AnalogInput 

 * Modified again by dave

 */

int potPin = A0;   // select the input pin for the potentiometer

int motorPin = 9; // select the pin for the Motor

int val = 0;      // variable to store the value coming from the sensor

void setup() {

  Serial.begin(9600);

  pinMode(9,OUTPUT);

  pinMode(A0,INPUT);

}

void loop() {

  val = analogRead(potPin);    

  Serial.println(val);

  analogWrite(motorPin, val/4); 

}