PIC16F690 and LCD (16*2) with 8 bit mode .

/*LPG LECKAGE DETECTION AND AUTO CALLING TO SELECTED PHONES
 * FINAL YEAR PROJECT
 * AMERICAN INTERNATIONAL UNIVERSITY-BANGLADESH
 * MD. SHAKHAWAT HOSSEN (ID: 08-11488-2)
 * MCU-PIC16RF690
 */

#include<pic.h>
#include<htc.h>
#define _XTAL_FREQ 4000000
__CONFIG (INTIO & WDTDIS & PWRTEN & MCLREN & UNPROTECT & UNPROTECT & BORDIS & IESODIS & FCMDIS);

#define  LCD 	PORTC
#define  rs 	RB4
//#define  rw 	RB5
#define  en 	RB5
#define  t 	10


void LCD_ini(unsigned  char com);
void LCD_data(unsigned  char cha);


void main(){
	//OSCCON=01100010;              //4MHz internal
	ANSEL=0x03;			// RA0 & RA1 are Analog.
	ANSELH=0;			//Rest of pins are digital.


	// Comparator Block
	TRISA0=1;                       // Ref input of Comparator.
	TRISA1=1;                       //Input of Comparator.
	TRISA2=0;                       //Output of Comparator.
	TRISA5=0;
	TRISA4=0;


	C1CH0=0;                        //To select -V pin out of 4
	C1CH1=0;                        // Here 00 pin(RA1) select

	C1R=0;                          //Select Referance pin(RA0)
	C1ON=1;                         //To ON the Comparator.
	C1POL=1;                        //To invert the comparator result.
	C1OE=1;                         //To eneble RA2 for getting result
	//Comparator Block

	//LCD Block
	TRISC=0x00;			// define output
	TRISB=0x00;			//define O/P
	//LCD Block

	int i,relay=1,count=1;
	RB6=0;				// Relay switch.
	RB7=0;				//LED blinking.


	LCD_ini(0x38);			//8 bit mode .
	LCD_ini(0x0C);			//Display on Cursor off.
	LCD_ini(0x80);			//Set DDRAM  & Cursor position on display

	while(1){


		if(C1OUT==0){
			relay=1;
			count=1;
			RB7=0;                          //LED blinking
			RB6=0;                          // Relay switch.

			LCD_ini(0x80);			//Set DDRAM  & Cursor position on display .
			unsigned  char j[]="GAS NOT FOUND... ";

			for (int i=0 ; i <(sizeof j) ;i++){
				LCD_data( j[i]);
				__delay_ms(t);
			}

			LCD_ini(0xC0);                  //	Start at 2nd row.

			unsigned  char m[]=" ############# ";

			for (int i=0 ; i <(sizeof m) ;i++){
				LCD_data(m[i]);
				__delay_ms(t);
			}
		}


		if(C1OUT==1){

			RB7=1;				//LED blinking


			LCD_ini(0x80);			//Set DDRAM  & Cursor position on display .
			unsigned  char k[]="   GAS FOUND !! ";

			for (int i=0 ; i <(sizeof k) ;i++){
				LCD_data(k[i]);
				__delay_ms(t);
			}

			LCD_ini(0xC0);                  //Start at 2nd row.

			RB7=0;				//LED blinking
			unsigned  char n[]="  Calling ............. !! ";

			for (int i=0 ; i <(sizeof n) ;i++){
				LCD_data(n[i]);
				__delay_ms(t);
			}

			if(relay<=2){
				RB6=1;			// Relay switch.
				relay++;
				__delay_ms(50*t);
				RB6=0;			// Relay switch.
			}
			if(count==40)	{
			relay=1;
			count=1;
			}
			count++;
		}
	}
}

void LCD_ini(unsigned  char com){

		LCD=com;
		en=1;
		rs=0;
		//rw=0;
		__delay_ms(t);
		en=0;
		__delay_ms(t);
	}

void LCD_data(unsigned  char cha){

		LCD=cha;
		en=1;
		rs=1;
		//rw=0;
		__delay_ms(t);
		en=0;
		__delay_ms(t);
		rs=0;
	}