Phone Table

Description:
I created a table which helps me focus on my work and prevents me from playing with my phone. When I lift the phone off the table it starts buzing. I wanted to make it unique to the phone by using the phone weight, so that the system could not be fooled by any other device, but I was not able to get that data accurately, so instead I used the photo sensor.
Components:
1 Arduino
1 110 ohm resistor
1 Photo sensor
1 cardboard assembly
1 speaker
Code:
 

/* Theremin

 * --------

 *

 *

 * Created 24 October 2006

 * copyleft 2006 Tod E. Kurt <tod@todbot.com

 * http://todbot.com/

 */

int potPin = 0;    // select the input pin for the potentiometer

int speakerPin = 7;

int val = 0;

void setup() {

  pinMode(speakerPin, OUTPUT); 

  Serial.begin(9600);

  Serial.println("ready");

}

void loop() {

  digitalWrite(speakerPin, LOW);

  val = analogRead(potPin);    // read value from the sensor

  val = val*2;                 // process the value a little

  //val = val/2;                 // process the value a little

  Serial.println(val);

  if(val>500)

  {

    for( int i=0; i<50; i++ )// play it for 50 cycles

    {

      digitalWrite(speakerPin, HIGH);

      delayMicroseconds(val);

      digitalWrite(speakerPin, LOW);

      delayMicroseconds(val);

    }

  }

  else

  {

    digitalWrite(speakerPin, LOW);

  }

}