LCD 4 Bit Interfacing with AVR

LCD 4 Bit Interfacing with AVR  -Atmega16

After interfacing with 8051 and PIC16f877  am providing AVR interfacing to LCD ,with a light changing in the previous code (ClikHere) .

I am taken Atmeg16 Controller . 

************* Please Comment If you have Doubt **********

/*
 * LCD4bit.c
 *
 * Created: 16-Sep-15 10:22:26 PM
 *  Author: Krishna
 */ 

#define F_CPU 12000000UL
#include <avr/io.h>
#include<util/delay.h>
#define LCDPORT PORTD   // Renaming the PORTD to LCDPORT
#define RS PD2          // Renaming the RS pin to 2 
#define E PD3            // Renaming the E to number 3
#define LINE2 lcd_cmd(0xc0);  
 void latch(void)  // used to a high to low pulse the pin E
 {
  PORTD |= ~(1<<E);  // here we give a high to PORTD.3
 _delay_ms(1);
  PORTD |= (1<<E);   // Here we give a LOW to PORTD.#
 }
 
 
 
 
 void lcd_cmd(unsigned char c)   // used to send the command / Instruction to the lcd port
 {
  PORTD |= ~(1<<RS);    // send a '0' value to select to send command
  _delay_ms(1);
  LCDPORT = c & 0xf0;  //  send  the command c only 4 bit by masking the lower bit
  latch();
  _delay_ms(1);
  LCDPORT =  (c << 4); // giving the lowerbit  by shifting the 4 bit to left
  latch();
 }

 void gotoxy(unsigned char  x,unsigned char y)  
{
 if(x<40)
 {
  if(y) x|=0b01000000;
  x|=0b10000000;
  lcd_cmd(x);
  }
 
 void lcd_data(unsigned char c)
 {
  PORTD |= (1<<RS);    // send 1 to send data
  _delay_ms(1);
  LCDPORT = c & 0xf0| 0x4; //send  the data  only  4 bit by masking the lower bit and also making the RS pin high by giving 0x04 .
  _delay_ms(1);
  latch();
  
  LCDPORT = (c << 4)| 0x4; ; // giving the lower bit  by shifting the 4 bit to left
  latch();
 }
 
  void lcd_init()
  {
   _delay_ms(20);
   lcd_cmd(0x30);  //as per data sheet
   _delay_ms(20);
   lcd_cmd(0x30);    //as per data sheet
   _delay_ms(4);
   lcd_cmd(0x32);    //as per data sheet
   _delay_ms(4);
   lcd_cmd(0x28);            // Function set (4-bit interface, 2 lines, 5*7Pixels)
   lcd_cmd(0x28);            // Function set (4-bit interface, 2 lines, 5*7Pixels)
   lcd_cmd(0x0c);            // Make cursorinvisible
   lcd_cmd(0x6);            // Set entry Mode(auto increment of cursor)
  }
 
  void string(const char *q)    // used to send single charcter to display the lcd
  {
   while (*q) {
    lcd_data(*q++);
   }
  }
 
 
void main(){
 
  DDRD = 0xFF;
 lcd_init();
  string("Lcd Testing ");
 LINE2
 string("its displaying ");
 while(1);
}

Circuit Diagram 

Downloa here the Full project including Proteus Click here