EMBEDDED SYSTEM PROJECT BLOG

LCD DISPLAY

NUR FIKRIYAH BINTI HASHIM 01DNS15F1034

NUR ARINA AMANI BINTI MOHD OTHMAN 01DNS15F1038

SHRMILA A/P JAYAGOBI 01DNS15F1031

Introduction

The character of LCD offers display numerical information, text message and also special symbol. We can control a LCD using either 8 pins or 4 pins, depending on the I/O pins that we have. Before using the LCD for display purpose, LCD has to be initialized either by the internal reset circuit or sending the commands to initialize the LCD.

List of Hardware, Software & Components

Hardware

1. LCD

2. PIC16F877A

Software

1. MPLAB IDE v8.83

2. Hi-Tech C Compiler v2.3

Circuit Diagram

The Coding

#include<htc.h>

//-------------- CONFIGURATION -----------------------------------------

__CONFIG (0x3F3A);

//-------------- DEFINE THE I/O PIN ------------------------------------

#define RS RA2 //RS pin of the LCD display

#define E RA3 //E pin of the LCD display

#define b_light RA1

#define lcd_data PORTD

#define d0 RD0

#define d1 RD1

#define d2 RD2

#define d3 RD3

#define d4 RD4

#define d5 RD5

#define d6 RD6

#define d7 RD7

#define SW1 RB0

#define SW2 RB1

//-------------- DEFINE VARIABLE DEFINITION --------------------------

//-------------- FUNCTION PROTOTYPE ----------------------------------

void delay(unsigned long data);

voide_pulse(void);

voidlcd_clr(void);

voidlcd_goto(unsigned char data);

voidsend_char(unsigned char data);

voidsend_config(unsigned char data);

voidsend_string(const char *s);

//-------------- MAIN FUNCTION (WRITE YOUR PROGRAM HERE) ---------------

void main()

{ //set I/O input output

TRISA=0b00000000; //Configure PORTA I/O direction

TRISB=0b00000111; //Configure PORTB I/O direction

TRISD=0b00000000; //Configure PORTD I/O direction

TRISE=0b00000000;

PORTA=0;

PORTB=0;

PORTC=0;

PORTD=0;

PORTE=0;

//setup ADC

ADCON1=0b00000110;

//set RA2, RA3 as digital and rest remain as analog I/O.

//Ensure pin share with analog is being configured to digital correctly

//Configure the LCD

send_config(0b00000001); //clear the LCD.

send_config(0b00000010); //Return cursor to home.

send_config(0b00000110); //Entry mode, cursor increase 1.

send_config(0b00001100); //Display on,cursor off and cursor blink off.

send_config(0b00111000); //Function set.

lcd_clr(); //Clear the LCD.

lcd_goto(2); //Put cursor on position 0.

send_string("HI WE ARE DNS4A:"); //Send string "HI WE ARE DNS4A".

lcd_goto(20); //Put cursor on position 11.

send_string("PUO"); //Send string "PUO".

lcd_goto(25); //Put cursor on position 20.

send_string("&"); //Send string "&".

lcd_goto(27); //Put cursor on position 26.

send_string("FROM JTMK PUO"); //Send string "FROM JTMK PUO".

b_light=1;

while(1)

{

if(SW1==0)

{

while(SW1==0);

lcd_clr();

lcd_goto(0);

send_string("DIS 16");

lcd_goto(20);

send_string("MY NAME IS NUR FIKRIYAH ");

}

else if(SW2==0)

{

while(SW2==0);

lcd_clr();

lcd_goto(0);

send_string("MY NAME IS ARINA ");

lcd_goto(22);

send_string("MY NAME IS SHRMILA");

}

}}

//Delay function. The delay time depends on the given value.

void delay(unsigned long data)

{

for(;data>0;data-=1);

}

voide_pulse(void) //Send a pulse to the E pin of the LCD.

{

E=1;

delay(50);

E=0;

delay(50);

}

//Send the configuration to the LCD.

voidsend_config(unsigned char data)

{

unsigned char test;

unsigned char i;

RS=0; //Clear RS pin for config mode.

for(i=0;i<8;i++) //Loop for 8 times.

est=(data>>i)&0b00000001; //Shift data to right.

switch(i) //Detect a byte of data one bit by one bit.

{

case 0:

if(test==1) d0=1;

else d0=0;

case 1:

if(test==1) d1=1;

else d1=0;

case 2:

if(test==1) d2=1;

else d2=0;

case 3:

if(test==1) d3=1;

else d3=0;

case 4:

if(test==1) d4=1;

else d4=0;

case 5:

if(test==1) d5=1;

else d5=0;

case 6:

if(test==1) d6=1;

else d6=0;

case 7:

if(test==1) d7=1;

else d7=0;

}

elay(50);

e_pulse();

}

//Clear the LCD

voidlcd_clr(void)

{

send_config(0x01);

delay(600);

}

//Set the location of the LCD cursor.

//If the given value is (0-15) the cursor will be at the upper line.

//If the given value is (20-35) the cursor will be at the lower line.

//Location of the lcd cursor (2x16):

// -----------------------------------------------------------

// ||00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15||

// ||20|21|22|23|24|25|26|27|28|29|30|31|32|33|34|35||

voidlcd_goto(unsigned char data)

{

if(data<16)

end_config(0x80+data);

}

else

ata=data-20;

send_config(0xC0+data);

elay(200);

}

//Send a character to the LCD.

voidsend_char(unsigned char data)

{

unsigned char test;

unsigned char i;

RS=1;

//Set RS for data mode.

for(i=0;i<8;i++) //Loop for 8 times.

{

test=(data>>i)&0b00000001; //Shift data to right.

switch(i) //Detect data one bit by one bit.

{