Software: KEIL micro vision 4.0
Simulator :Proteus 8.0
Circuit diagram:
Program:
#include<reg51.h>
sbit RS = P2^0; // REGISTER SELECT
sbit RW = P2^1; // READ/WRITE
sbit EN = P2^2; // ENABLE
void delay(int t); //delay function
void lcd_init(void); //initialization of lcd
void lcd_command(char c); // lcd command function
void lcd_data(char d); //lcd data function
void str(char a[]); // lcd string function
void main() // main program
{
lcd_init();
str("welcome"); // data to be displayed on lcd.
while(1);
}
void lcd_init(void)
{
lcd_command(0x38); //8 bit,2 line,5x7 dots
lcd_command(0x01); // clear dispay
lcd_command(0x0f); //display on,cursor blinking
lcd_command(0x06);
lcd_command(0x80); // force cursor to begining of first row
}
void lcd_command(char c)
{
P1=c; //send command to port1
RS=0; //select command register to send command
RW=0; // write operation
EN=1; // send high to low pulse on enable pin of lcd
delay(5);
EN=0;
delay(5); // delay
}
void lcd_data(char d)
{
P1=d; //send data to port1
RS=1; //select data register to send data
RW=0; // write operation
EN=1; // send high to low pulse on enable pin of lcd
delay(5);
EN=0;
delay(5); // delay
}
void delay(int t)
{
int j;
for(j=0;j<t*1275;j++);
}
void str(char a[])
{
int j;
for(j=0;a[j]!='\0';j++)
{
lcd_data(a[j]); //pass string to array
}
}
Program Description:
First I have initialized the lcd by providing various lcd commands.In lcd command function,in order to pass that commands I have select RS(p2.0) as '0' in order to select command register.After that to enable write operation R/W(p2.1) is provided with '0'.To pass that commands to lcd I have provided high to low pulse on EN(p2.2) of lcd.
After passing command,I have send data (which needs to be displayed on lcd) which is in a string format to string function.In string function I have provided one by one character of string in array format to lcd data function.In lcd data function one by one character is provided to port 1.
In lcd data function all the operations remain same as in the lcd command function only RS(p2.0) is provided with '1' in order to select data register.Delay is provided in between for synchronization.
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