Info Interfacing LCD with PIC16F877A in MPLAB X

Most of the embedded projects have some user interfaces, most of them uses LCD displays for output

Here we are going to see how to interface an 16x2 LCD with PIC16F877A

First Create a MPLAB X project as in the steps for  Blinking a LED using MPLAB X , PIC16F877A


Components
1.PIC16F877A micro controller
2. 2x16 LCD Display




Most of the  LCD have 16 Pins
3 Control Pins
8 Data Pins
4 Power Pins

Steps For Interfacing LCD 

1. Take two ports make one as input and other as output by loading 1 to TRIS register and 0 to TRIS respectively

             Step 1: Initialize the LCD.

          The LCD must be initialized the by following pre-defined commands of character LCD.

·         0x38, to configure the LCD for 2-line, 5x7 font and 8-bit operation mode

·         0x0C, for Display On and Cursor Off

·         0x01, to Clear Display screen

·         0x06, to increment cursor

·         0x80, to set cursor position at first block of the first line of LCD.

Step 2: Send the commands to LCD.

·         Send the command byte to the port connected to LCD data pins

·         RS=0, to select command register of LCD

·         RW=0, to set the LCD in writing mode

·         EN=1, a high to low pulse to latch command instruction

·         Delay of 1ms

·         EN=0

Step 3: Send data to LCD.

·         Send data at the port which connected to LCD data pins

·         RS=1, register select to select data register of LCD

·         RW=0, this set the LCD in writing mode

·         EN=1, a high to low pulse to latch data

·         Delay of 1ms

·         EN=0

Step 4: Display character on LCD.

The functions lcdcmd() and lcddata() are user-defined functions. They are used to send a character (E in this case) to be displayed on LCD.

LCD_CMD(0x38);             // send command 0x38 to LCD

LCD_DAT(‘E’);                // send character E to LCD

schematic diagram :

THE PROGRAM IS AVAILABLE ON GITHUB : https://github.com/ebine/lcd-interface-pic16f877a


# include<htc.h>

#if defined(WDTE_OFF)
__CONFIG(WDTE_OFF & LVP_OFF);
#elif defined (WDTDIS)
__CONFIG(WDTDIS & LVPDIS);
#endif

#define RS RE0
#define RW RE1
#define EN RE2
#define DATA PORTB

void LCD_CMD(unsigned int value);
void LCD_DAT(unsigned int value);
void delay();


int main(void)
{
    ADCON0 = 0x00;//Disable ADC ports
    ADCON1 = 0x06;//Disable ADC ports

    TRISE =0x00;
    TRISB =0x00;
    //DATA=0x01;
    LCD_CMD(0x01);
    delay ();
    LCD_CMD(0x38);
    delay ();
    LCD_CMD(0x0F);
    delay ();
   // LCD_CMD(0x07);
    delay();
    LCD_CMD(0x06);
    delay ();
    LCD_CMD(0x0c);
    delay ();


    LCD_CMD(0x80);
    delay ();

    //DATA='A';
    LCD_DAT('S');
    LCD_DAT('E');
    LCD_DAT('R');
    LCD_DAT('V');
    LCD_DAT('4');
    LCD_DAT('U');

    LCD_CMD(0x80);
     while(1);
    return (0);

}

void LCD_CMD(unsigned int value)
{
    DATA =value;
    RS=0;
    RW=0;
    EN=1;
    delay ();
    EN=0;
    delay ();
 }

void LCD_DAT(unsigned int value)
{
    DATA=value;
    RS=1;
    RW=0;
    EN=1;
    delay ();
    EN=0;
    delay();

}

void delay(void)
{
    int counter = 0;
    for (counter = 0; counter<10000; counter++) {
        ;
    }
}