#include<reg51.h>

sbit D7=P2^7;
sbit D6=P2^6;
sbit D5=P2^5;
sbit D4=P2^4;

sbit rs=P2^0; /* Register select pin */
sbit en=P2^1; /* Enable pin */

//#define LCD_Port P1
int LCD_Port ;

/* Function to provide delay Approx 1ms with 11.0592 Mhz crystal*/
void delay(unsigned int count)
{
int i,j;
for(i=0;i<count;i++)
for(j=0;j<112;j++);
}

void LCD_Command (char cmnd) /* LCD16x2 command funtion */
{
LCD_Port = (cmnd & 0xF0)>>4;/* Send upper nibble */
D7=LCD_Port&0X08;
D6=LCD_Port&0X04;
D5=LCD_Port&0X02;
D4=LCD_Port&0X01;
rs=0; /* Command reg. */
// rw=0; /* Write operation */
en=1;
delay(1);
en=0;
delay(2);

LCD_Port = (cmnd & 0x0F);/* Send lower nibble */
D7=LCD_Port&0X08;
D6=LCD_Port&0X04;
D5=LCD_Port&0X02;
D4=LCD_Port&0X01;
rs=0;
en=1; /* Enable pulse */
delay(1);
en=0;
delay(5);
}

void LCD_Char (char char_data) /* LCD data write function */
{
LCD_Port =(char_data & 0xF0)>>4;/* Send upper nibble */
D7=LCD_Port&0X08;
D6=LCD_Port&0X04;
D5=LCD_Port&0X02;
D4=LCD_Port&0X01;
rs=1; /*Data reg.*/
// rw=0; /*Write operation*/
en=1;
delay(1);
en=0;
delay(2);

LCD_Port = (char_data & 0x0F);/* Send lower nibble */
D7=LCD_Port&0X08;
D6=LCD_Port&0X04;
D5=LCD_Port&0X02;
D4=LCD_Port&0X01;
en=1; /* Enable pulse */
delay(1);
en=0;
delay(5);

}

void LCD_String (char *str) /* Send string to LCD function */
{
int i;
for(i=0;str[i]!=0;i++) /* Send each char of string till the NULL */
{
LCD_Char (str[i]); /* Call LCD data write */
}
}

void LCD_String_xy (char row, char pos, char *str) /* Send string to LCD function */
{
if (row == 0)
LCD_Command((pos & 0x0F)|0x80);
else if (row == 1)
LCD_Command((pos & 0x0F)|0xC0);
LCD_String(str); /* Call LCD string function */
}

void LCD_Init (void) /* LCD Initialize function */
{
delay(20); /* LCD Power ON Initialization time >15ms */
LCD_Command (0x02); /* 4bit mode */
LCD_Command (0x28); /* Initialization of 16X2 LCD in 4bit mode */
LCD_Command (0x0C); /* Display ON Cursor OFF */
LCD_Command (0x06); /* Auto Increment cursor */
LCD_Command (0x01); /* clear display */
LCD_Command (0x80); /* cursor at home position */
}

void main()
{
LCD_Init(); /* Initialization of LCD*/
LCD_String("RDL TECHOLOGIES"); /* write string on 1st line of LCD*/
LCD_Command(0xC0); /* Go to 2nd line*/
LCD_String_xy(1,0,"lcd display"); /*write string on 2nd line*/
while(1); /* Infinite loop. */
}