Interfacing LCD without a potentiometer( In Arduino and CCS)

I was reading on LCD interfacing and came across alot of people having trouble interfacing LCD with the pot setting for contrast. So here is a detailed solution of skiping installing a pot all together and using PWM signal to adjust the contrast.

For the Arduino solution the following is the hardware i used:

1. Arduino UNO

2. 16x2 LCD (JHD162A)

Instructions: Burn the code and enter on the Serial Monitor A to increase contrast and B to decrease  the contrast and turn on back-light enter N and to turn it off enter F.

The following is the code

*/

Library Originally added by David A Mellis

Library Modified by Limor Fried
Example added by Tom Igoe
Modified by Tom Igoe
This example is in the public domain. http://www.arduino.cc.en/Tutorial/LiquidCrystal
Contrast modification by Ahmed Murtaza Qureshi (www.engineeringlearning.blogspot.com)
/*

#include <LiquidCrystal.h>

char ch;

int Contrast=15;

// initialize the library with the numbers of the interface pins

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() 

{

  Serial.begin(9600);

  Serial.println("LCD test with PWM contrast adjustment");

  pinMode(13,OUTPUT);

  analogWrite(6,Contrast);

  // set up the LCD's number of columns and rows: 

  lcd.begin(16, 2);

  // Print a message to the LCD.

  lcd.print("LCD test!!");

}

void loop() 

{

   digitalWrite(13,LOW);

   delay(1000);

   digitalWrite(13,HIGH);

  // set the cursor to column 0, line 1

  // (note: line 1 is the second row, since counting begins with 0):

  lcd.setCursor(0, 1);

  // print the number of seconds since reset:

  lcd.print(millis()/1000);

}

void serialEvent()

{

     if (Serial.available())

  {

    ch= Serial.read();

    if(ch=='A' && Contrast<255)

    {

      Contrast=Contrast+1;

    }

    if(ch=='B' && Contrast>0)

    {

      Contrast=Contrast-1;

    }

        if(ch=='N')

    {

      analogWrite(9,28836);

    }

       if(ch=='F')

    {

      analogWrite(9,0);

    }

    analogWrite(6,Contrast);

    Serial.println("Current contrast");

    Serial.println(Contrast);

  }

}