Program to interface lcd in 4 bit mode [Embedded systems Lab]

//***Program to interface lcd in 4 bit mode***//

//*** by hiq test equipment ***//

#include<reg52.h>

sbit rs  =P2^0;//initialize rs(Register Select) pin to P2.0

sbit en  =P2^1;//initialize en(Enable) pin to P2.1

sbit db4 =P2^2;//initialize db4  pin to P2.2

sbit db5 =P2^3;//initialize db5  pin to P2.3

sbit db6 =P2^4;//initialize db6  pin to P2.4

sbit db7 =P2^5;//initialize db7  pin to P2.5

       

void init_lcd(void);

void cmd_lcd(unsigned char);

void write_lcd(unsigned char);

void display_lcd(unsigned char *);

void delay_ms(unsigned int);

void main(void)

{

init_lcd(); 

delay_ms(500);

init_lcd();

init_lcd();

init_lcd();

delay_ms(100);

while(1) 

{

cmd_lcd(0x01);

display_lcd("GOOD MORNING");

cmd_lcd(0xc0);

display_lcd("    EVERYBODY  ");                                      

delay_ms(1000);

cmd_lcd(0x01);

display_lcd("   WELCOME TO");

cmd_lcd(0xc0);

display_lcd("HI-Q TEST EQUIP ");

delay_ms(1000);

}

}

void init_lcd(void)

{                            

delay_ms(10); 

cmd_lcd(0x28);//lcd initializing as 4-bit mode 16x2 character  

cmd_lcd(0x0e);//cursor blinking

cmd_lcd(0x06);//cursor right shifts 

cmd_lcd(0x01);//clear lcd

}

void cmd_lcd ( unsigned char c )

{

  unsigned char temp;

  temp = c & 0xf0;         //Transmitting high byte

   rs = 0;

  en = 1;

  db7 = temp & 0x80;

  db6 = temp & 0x40;

  db5 = temp & 0x20;

  db4 = temp & 0x10;

  en = 0;

  temp = c & 0x0f;          //Transmitting low byte

  rs = 0;

  en = 1;

  db7 = temp & 0x08;

  db6 = temp & 0x04;

  db5 = temp & 0x02;

  db4 = temp & 0x01;

  en = 0;        

   delay_ms(10);

}

void write_lcd ( unsigned char c )

{

  unsigned char temp;

  temp = c & 0xf0;        //Transmitting high byte

  rs = 1;

  en = 1;

  db7 = temp & 0x80;

  db6 = temp & 0x40;

  db5 = temp & 0x20;

  db4 = temp & 0x10;

  en = 0;

  temp = c & 0x0f;             //Transmitting low byte

   rs = 1;

  en = 1;

  db7 = temp & 0x08;

  db6 = temp & 0x04;

  db5 = temp & 0x02;

   db4 = temp & 0x01;

  en = 0;        

  delay_ms(10); 

}

void display_lcd(unsigned char *s)

{

while(*s)

write_lcd(*s++);

}

void delay_ms(unsigned int i)

{

unsigned int j;

while(i-->0)

{

for(j=0;j<500;j++);

}

}

   

asve it as   LCD.c