PIC16F887 HD44780 4-Bit LCD Example Using XC8

In previous tutorial, I use a PIC16F887 controller to interface with an HD44780 character LCD module in 8-bit mode. However most of this electronics designer use a 4-bit mode operation. Data transferring to this LCD is still 8-bit wide but it sends twice, first the higher nibble then the lower nibble of data byte. This can save the number of microprocessor I/O pins.

Prototype Board Testing

The programming is no complex. The controller just process the transferring of these two nibbles of data byte. LCD control pins remain the same as per in previous example. We only use the higher nibble (DB4...D7) of LCD for data bus. The lower nibble (DB0...D3) must left blank or connects to ground.

The following example display the system running time since it starts up.

/*
 * File:   main.c
 * Author: Admin
 *
 * Created on December 20, 2023, 7:36 PM
 * HD44780 8-BIT LCD WITH PIC16F887
 * MPLABX IDE v6.15 AND XC8 2.36
 */
 
#include <stdio.h>
#include <xc.h>
#include "config.h"
 
#define _XTAL_FREQ  8000000UL
 
#define DB  PORTD
#define DR  TRISD
#define RS  RD0
#define EN  RD1
 
/*LCD Command RS=0*/
void lcdCommand(char command){
    DB=command&0xF0;
    RS=0;
    EN=1;
    __delay_us(25);
    EN=0;
    __delay_us(25);
 
    DB=command<<4;
    RS=0;
    EN=1;
    __delay_us(25);
    EN=0;
    __delay_us(250);
}
 
/*LCD Data RS=1*/
void lcdData(char data){
    DB=data&0xF0;
    RS=1;
    EN=1;
    __delay_us(25);
    EN=0;
    __delay_us(25);
 
    DB=data<<4;
    RS=1;
    EN=1;
    __delay_us(25);
    EN=0;
    __delay_us(250);
}
 
void lcdXY(char x, char y){
    // 16x2
    char addr[]={0x80,0xC0};
    lcdCommand(addr[y-1]+x-1);
}
 
void lcdString(char *str){
    while(*str) lcdData(*str++);
    __delay_us(25);
}
 
void lcdInit(void){
    DB=0;
    DR=0;
    __delay_ms(10);
    lcdCommand(0x33);
    lcdCommand(0x32);
    lcdCommand(0x28);
    lcdCommand(0x0C);
    lcdCommand(0x01);
    __delay_ms(5);
    lcdCommand(0x06);
    __delay_us(100);
}
 
void main(void) {
    char seconds=0,minutes=0,hours=0;
    int days=0;
    char message[16];
    /*Internal 8MHz RC OSC*/
    OSCCONbits.IRCF=7;
    lcdInit();
    lcdString("PIC16F887 4-BIT");
    lcdXY(3,2);
    lcdString("HD44780 LCD");
    __delay_ms(2500);
    lcdCommand(0x01);
    __delay_ms(5);
    lcdXY(4,1);
    lcdString("Started Up:");     
    while(1){
        if(seconds>59){seconds=0; minutes++;}
        if(minutes>59){minutes=0; hours++;}
        if(hours>23){hours=0; days++;}
        sprintf(message,"%4d - %2d:%2d:%2d",days,hours,minutes,seconds);
        lcdXY(1,2); lcdString(message);
        seconds++;      
        __delay_ms(1000);
    }
    return;
}
 

Click here to download its source file, or with LCD library.

MPLABX IDE v6.15 is pretty nice to use. 

I use my own PIC16F887 prototype board to test this example program.

Prototype Board Testing