How to display text on 16x2 LCD using 8051 microcontroller (AT89C51)- (Part 7/45)

Several electronic devices and projects require a message to be displayed in order to indicate their functioning. This topic explains how to display a message (string) on 16x2 LCD by interfacing it to 8051 microcontroller (AT89C51).

A single character can be displayed on LCD by properly configuring its data and command registers. A string is nothing but a sequential arrangement of several characters that can be displayed on LCD by using the following algorithm. Here P2 port of the microcontroller is used as output port which sends the data byte to data pins of the LCD. The control pins (pin 4, 5 & 6) are connected to pins 0, 1 & 6, respectively, of P3 port of the microcontroller. Pin 3 is connected to a preset of 10k to adjust the contrast on LCD screen

Fig. 2: LCD Screen

Project Source Code

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//Program to display String on LCD

#include<reg51.h>
sfr lcd_data_pin=0xA0;  // data port P2
sbit rs=P3^0; // Register select pin
sbit rw=P3^1; // Read write pin
sbit en=P3^6; // Enable pin
void delay(unsigned int msec)    //delay function
{
int i,j;
for(i=0;i<msec;i++)
for(j=0;j<1275;j++);
}
void lcd_command(unsigned char comm) // function to send command to LCD
{
lcd_data_pin=comm;
en=1;
rs=0;
rw=0;
delay(1);
en=0;
}
void lcd_data(unsigned char disp)    // function to send data on LCD
{
lcd_data_pin=disp;
en=1;
rs=1;
rw=0;
delay(1);
en=0;
}

lcd_dataa(unsigned char *disp)    // function to send string to LCD
{
int x;
for(x=0;disp[x]!=0;x++)
{
lcd_data(disp[x]);

}
}

void lcd_ini()     //Function to inisialize the LCD
{
lcd_command(0x38);   
delay(5);
lcd_command(0x0F);       
delay(5);
lcd_command(0x80);
delay(5);
  

}
void main()
{
lcd_ini();
lcd_dataa("ECE Rocks");
}

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