LCD interfacing with ATMEGA32 AVR MICROCONTROLLER

WHAT IS LCD?

PIN DESCRIPTION OF LCD

HOW TO PROGRAM LCD?

SENDING COMMANDS ON LCD

SENDING DATA ON LCD

SCHEMATIC

CODE FOR INTERFACING LCD

#ifndef F_CPU

# define F_CPU 16000000UL // clock speed is 16MHz

#endif

 

#include<avr/io.h>        // AVR header

#include<util/delay.h>    // delay header

 

//******************LCD PROGRAM STARTS*********************//

#define LCD_DATA PORTB          // port B is selected as LCD data port

#define ctrl PORTD              //  port D is selected as LCD command port

#define en PD7                  // enable signal is connected to port D pin 7

#define rw PD6                  // read/write signal is connected to port D pin 6

#define rs PD5                  // register select signal is connected to port D pin 5

 

void LCD_cmd(unsigned char cmd);

void init_LCD(void);

void LCD_write(unsigned char data);

 

int main(void)

{

DDRB=0xFF;              // set LCD data port as output

DDRD=0xE0;              // set LCD signals (RS, RW, E) as out put

init_LCD();             // initialize LCD

_delay_ms(100);         // delay of 100 Milli seconds

 

LCD_cmd(0x0C);          // display on, cursor off

_delay_ms(100);

 

LCD_write(‘ ‘);         // call a function to display space on LCD

_delay_ms(1);

LCD_write(‘ ‘);         // call a function to display space on LCD

_delay_ms(1);

LCD_write(‘ ‘);         // call a function to display space on LCD

_delay_ms(1);

LCD_write(‘ ‘);         // call a function to display space on LCD

_delay_ms(1);

LCD_write(‘ ‘);         // call a function to display space on LCD

_delay_ms(1);

LCD_write(‘A’);         // call a function to display “A” on LCD

_delay_ms(100);

LCD_write(‘V’);         // call a function to display “V” on LCD

_delay_ms(100);

LCD_write(‘R’);         // call a function to display “R” on LCD

_delay_ms(100);

 

LCD_cmd(0xC0);          // move cursor to the start of 2nd line

_delay_ms(100);

 

LCD_cmd(0x0C);          // display on, cursor off

_delay_ms(100);

 

LCD_write(‘ ‘);         // call a function to display space on LCD

_delay_ms(1);

LCD_write(‘ ‘);

_delay_ms(1);

LCD_write(‘ ‘);

_delay_ms(1);

LCD_write(‘A’);        // call a function to display “A” on LCD

_delay_ms(100);

LCD_write(‘t’);        // call a function to display “t” on LCD

_delay_ms(100);

LCD_write(‘m’);        // call a function to display “m” on LCD

_delay_ms(100);

LCD_write(‘e’);        // call a function to display “e” on LCD

_delay_ms(100);

LCD_write(‘g’);        // call a function to display “g” on LCD

_delay_ms(100);

LCD_write(‘a’);        // call a function to display “a” on LCD

_delay_ms(100);

LCD_write(‘3’);        // call a function to display “3” on LCD

_delay_ms(100);

LCD_write(‘2’);        // call a function to display “2” on LCD

_delay_ms(100);

LCD_cmd(0x0E);          // make display ON, cursor ON

_delay_ms(1);

 

return 0;

}

void init_LCD(void)

{

LCD_cmd(0x38);           // initialization in 8bit mode of 16X2 LCD

_delay_ms(1);

LCD_cmd(0x01);          // make clear LCD

_delay_ms(1);

LCD_cmd(0x02);          // return home

_delay_ms(1);

LCD_cmd(0x06);          // make increment in cursor

_delay_ms(1);

LCD_cmd(0x80);          // “8” go to first line and “0” is for 0th position

_delay_ms(1);

 

return;

}

 

//**************sending command on LCD***************//

void LCD_cmd(unsigned char cmd)

{

LCD_DATA = cmd;      // data lines are set to send command

PORTD  &= ~(1<<rs);  // RS sets 0

PORTD  &= ~(1<<rw);  // RW sets 0

PORTD  |= (1<<en);   // make enable from high to low

_delay_ms(100);

PORTD  &= ~(1<<en);

 

return;

}

 

//*****************write data on LCD*****************//

void LCD_write(unsigned char data)

{

LCD_DATA= data;       // data lines are set to send command

PORTD  |= (1<<rs);    // RS sets 1

PORTD  &= ~(1<<rw);   // RW sets 0

PORTD  |= (1<<en);    // make enable from high to low

_delay_ms(100);

PORTD &= ~(1<<en);

 

return ;

}

SIMULATION ON PROTEUS