Nombres premiers

Nombres premiers

Réalisation

Voici une petite réalisation qui consiste en un petit cadre contenant un afficheur LCD 2×16 lignes (HD44780 compatible). Cet afficheur affiche les nombres premiers calculés par l'µC (un attiny2313).
C'est un truc assez sympa qu'on peut accrocher à un mur. Ca rend pas mal :-P .
Voici une petite photo si vous voulez-vous faire une idée:

Premièrement, on fait le schéma:

NB: ce schéma est faux. Les pins 1,3 et 2 du LCD doivent s'inverser. J'ai de plus simplifié la connexion Attiny2313-LCD.

Ensuite, on commence à faire le circuit sur une veroboard:

On ajoute ensuite les autres composants ainsi que les straps:

Enfin, on ajoute l'afficheur LCD ainsi que le joli cadre en plexi:

Erreurs à ne pas commettre

Quelques petites erreurs que j'ai fait et qui vous éviteront bien des ennuis si vous ne les faites pas :-P .

Si vous installez un 78L05, veuillez à ne pas le brancher à l'envers, sinon, ca ne marche pas.
Si vous changez votre 78L05 par un 7805, vérifiez que vous n'avez pas soudé un LM317 à la place :-? .
Enfin, si quand vous soudez votre véritable 7805, vous constatez que celui-ci est brulant, c'est peut-être par ce que vous avez mis les pins 1,3 du LCD au +5V et le 2 au GND au lieu de mettre les pins 1 et 3 au GND et le 2 au +5V.

Code source de la chose

Ce joli (:p) générateur de nombres premiers tourne sous un Attiny2313. Le code source devrait être compatible avec d'autres µC mais je n'ai pas testé. A vous de voir.
Le code utilise la lib. LCD de Peter Fleury, donc les fichiers lcd.c et lcd.h ne sont pas de moi.
Voici le code source (c'est pas très optimisé, mais ca marche :p):

main.c

/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <frank[ASCII:64]villaro-dixon.eu> wrote this file. As long as you retain this
 * notice, you can do whatever you want with this stuff. If we meet some day,
 * and you think this stuff is worth it, you can buy me a beer in return.
 * Frank Villaro-Dixon
 * ----------------------------------------------------------------------------
 */
 
/*
 *Calculateur de nombres premiers et affichage sur un LCD 2x16
 */
 
/* **
Pour le branchement du LCD, vous pouvez allez voir le fichier lcd.h
1 -> GND
2 -> VCC
3 -> GND
4 -> AVR.PB7
5 -> AVR.PB6
6 -> AVR.PB5
7 -> NC
8 -> NC
9 -> NC
10 -> NC
11 -> AVR.PB0
12 -> AVR.PD6
13 -> AVR.PB1
14 -> AVR.PB2
15 -> VCC          //Sur mon LCD, 15 et 16 sont inversés. A vous de voir !
16 -> GND+RES 680
Comme vous avez pu le remarquer, si vous alignez la patte 4 du LCD avec le pin 19 de l'Attiny2313, vous n'avez que deux branchements à rerouter (pin 13 et 14 du LCD).
 
*/
 
 
#define F_CPU 8000000UL
#include <avr/io.h>
#include <util/delay.h>
#include "lcd.h"
 
const unsigned long int primeMax = 33554432;
unsigned long int primeLast=2;
unsigned long int primeTest=0;
unsigned int primeDivy=0;
char s1[9] = {' ',' ',' ',' ',' ',' ',' ', ' ', '\0'};
 
void numtostring(unsigned long int temp, char numstring[])
{
    int x;
    for(x = 8; x >= 0 ;x--)
    {
        numstring[x] = (temp % 10) + 0x30;
        temp /= 10;
    }
}
 
void init(void);
void updateDisplay(void);
 
int main(void){
    _delay_ms(100);
    short maybePrime;
    unsigned int i;
    init();
 
    for(primeTest=2;primeTest<primeMax;primeTest++){
        maybePrime=1;
        for (i=2;i<=(primeTest/32);i++){
            primeDivy=i;
            //updateDisplay();
            if (primeTest%primeDivy==0){maybePrime=0;break;}
        }
        if (maybePrime==1){primeLast=primeTest;updateDisplay();}
    }
    return 0;
}
 
void updateDisplay(void){
    lcd_gotoxy(4,1);
    numtostring(primeLast, s1);
    //s1[7] = '/0';
    lcd_puts(s1);
    /*lcd_gotoxy(5,1);
    numtostring(primeTest, s1);
    lcd_puts(s1);
    lcd_gotoxy(16,1);
    numtostring(primeDivy, s1);
    lcd_puts(s1);*/
    //_delay_ms(1000);
    return;
}
 
void init(void){
    lcd_init(LCD_DISP_ON);
    lcd_clrscr();
    lcd_puts("Nb premiers, FVD\n");
    lcd_puts("   Juin 2010    ");
    _delay_ms(1000);
    lcd_init(LCD_DISP_ON);
    lcd_clrscr();
    lcd_puts("DERNIER PREMIER:\n");
    lcd_puts(">              <");
    return;
}

lcd.c

/****************************************************************************
 Title	:   HD44780U LCD library
 Author:    Peter Fleury <pfleury@gmx.ch>  http://jump.to/fleury
 File:	    $Id: lcd.c,v 1.13.2.2 2004/02/12 21:08:25 peter Exp $
 Software:  AVR-GCC 3.3
 Target:    any AVR device, memory mapped mode only for AT90S4414/8515/Mega
 
 DESCRIPTION
       Basic routines for interfacing a HD44780U-based text lcd display
 
       Originally based on Volker Oth's lcd library,
       changed lcd_init(), added additional constants for lcd_command(),
       added 4-bit I/O mode, improved and optimized code.
 
       Library can be operated in memory mapped mode (LCD_IO_MODE=0) or in
       4-bit IO port mode (LCD_IO_MODE=1). 8-bit IO port mode not supported.
 
       Memory mapped mode compatible with Kanda STK200, but supports also
       generation of R/W signal through A8 address line.
 
 USAGE
       See the C include lcd.h file for a description of each function
 
*****************************************************************************/
//#define F_CPU 8000000UL
#include <inttypes.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#include "lcd.h"
 
 
 
/*
** constants/macros
*/
#define PIN(x) (*(&x - 2))  /* address of data direction register of port x */
#define DDR(x) (*(&x - 1))  /* address of input register of port x          */
 
 
#if LCD_IO_MODE
#define lcd_e_delay()   __asm__ __volatile__( "rjmp 1f\n 1:" );
#define lcd_e_high()    LCD_E_PORT  |=  _BV(LCD_E_PIN);
#define lcd_e_low()     LCD_E_PORT  &= ~_BV(LCD_E_PIN);
#define lcd_e_toggle()  toggle_e()
#define lcd_rw_high()   LCD_RW_PORT |=  _BV(LCD_RW_PIN)
#define lcd_rw_low()    LCD_RW_PORT &= ~_BV(LCD_RW_PIN)
#define lcd_rs_high()   LCD_RS_PORT |=  _BV(LCD_RS_PIN)
#define lcd_rs_low()    LCD_RS_PORT &= ~_BV(LCD_RS_PIN)
#endif
 
#if LCD_IO_MODE
#if LCD_LINES==1
#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_4BIT_1LINE
#else
#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_4BIT_2LINES
#endif
#else
#if LCD_LINES==1
#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_8BIT_1LINE
#else
#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_8BIT_2LINES
#endif
#endif
 
 
/*
** function prototypes
*/
#if LCD_IO_MODE
static void toggle_e(void);
#endif
 
/*
** local functions
*/
 
 
 
/*************************************************************************
 delay loop for small accurate delays: 16-bit counter, 4 cycles/loop
*************************************************************************/
static inline void _delayFourCycles(unsigned int __count)
{
    if ( __count == 0 )
        __asm__ __volatile__( "rjmp 1f\n 1:" );    // 2 cycles
    else
        __asm__ __volatile__ (
    	    "1: sbiw %0,1" "\n\t"
    	    "brne 1b"                              // 4 cycles/loop
    	    : "=w" (__count)
    	    : "0" (__count)
    	   );
}
 
 
/*************************************************************************
delay for a minimum of <us> microseconds
the number of loops is calculated at compile-time from MCU clock frequency
*************************************************************************/
#define delay(us)  _delayFourCycles( ( ( 1*(XTAL/4000) )*us)/1000 )
 
 
#if LCD_IO_MODE
/* toggle Enable Pin to initiate write */
static void toggle_e(void)
{
    lcd_e_high();
    lcd_e_delay();
    lcd_e_low();
}
#endif
 
 
/*************************************************************************
Low-level function to write byte to LCD controller
Input:    data   byte to write to LCD
          rs     1: write data
                 0: write instruction
Returns:  none
*************************************************************************/
#if LCD_IO_MODE
static void lcd_write(uint8_t data,uint8_t rs)
{
    unsigned char dataBits ;
 
 
    if (rs) {   /* write data        (RS=1, RW=0) */
       lcd_rs_high();
    } else {    /* write instruction (RS=0, RW=0) */
       lcd_rs_low();
    }
    lcd_rw_low();
 
    if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
      && (LCD_DATA0_PIN == 0) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )
    {
        /* configure data pins as output */
        DDR(LCD_DATA0_PORT) |= 0x0F;
 
        /* output high nibble first */
        dataBits = LCD_DATA0_PORT & 0xF0;
        LCD_DATA0_PORT = dataBits |((data>>4)&0x0F);
        lcd_e_toggle();
 
        /* output low nibble */
        LCD_DATA0_PORT = dataBits | (data&0x0F);
        lcd_e_toggle();
 
        /* all data pins high (inactive) */
        LCD_DATA0_PORT = dataBits | 0x0F;
    }
    else
    {
        /* configure data pins as output */
        DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN);
        DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN);
        DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN);
        DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN);
 
        /* output high nibble first */
        LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN);
        LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN);
        LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN);
        LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);
    	if(data & 0x80) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);
    	if(data & 0x40) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);
    	if(data & 0x20) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);
    	if(data & 0x10) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);
        lcd_e_toggle();
 
        /* output low nibble */
        LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN);
        LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN);
        LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN);
        LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);
    	if(data & 0x08) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);
    	if(data & 0x04) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);
    	if(data & 0x02) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);
    	if(data & 0x01) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);
        lcd_e_toggle();
 
        /* all data pins high (inactive) */
        LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);
        LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);
        LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);
        LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);
    }
}
#else
#define lcd_write(d,rs) if (rs) *(volatile uint8_t*)(LCD_IO_DATA) = d; else *(volatile uint8_t*)(LCD_IO_FUNCTION) = d;
/* rs==0 -> write instruction to LCD_IO_FUNCTION */
/* rs==1 -> write data to LCD_IO_DATA */
#endif
 
 
/*************************************************************************
Low-level function to read byte from LCD controller
Input:    rs     1: read data
                 0: read busy flag / address counter
Returns:  byte read from LCD controller
*************************************************************************/
#if LCD_IO_MODE
static uint8_t lcd_read(uint8_t rs)
{
    uint8_t data;
 
 
    if (rs)
        lcd_rs_high();                       /* RS=1: read data      */
    else
        lcd_rs_low();                        /* RS=0: read busy flag */
    lcd_rw_high();                           /* RW=1  read mode      */
 
    if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
      && ( LCD_DATA0_PIN == 0 )&& (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )
    {
        DDR(LCD_DATA0_PORT) &= 0xF0;         /* configure data pins as input */
 
        lcd_e_high();
        lcd_e_delay();
        data = PIN(LCD_DATA0_PORT) << 4;     /* read high nibble first */
        lcd_e_low();
 
        lcd_e_delay();                       /* Enable 500ns low       */
 
        lcd_e_high();
        lcd_e_delay();
        data |= PIN(LCD_DATA0_PORT)&0x0F;    /* read low nibble        */
        lcd_e_low();
    }
    else
    {
        /* configure data pins as input */
        DDR(LCD_DATA0_PORT) &= ~_BV(LCD_DATA0_PIN);
        DDR(LCD_DATA1_PORT) &= ~_BV(LCD_DATA1_PIN);
        DDR(LCD_DATA2_PORT) &= ~_BV(LCD_DATA2_PIN);
        DDR(LCD_DATA3_PORT) &= ~_BV(LCD_DATA3_PIN);
 
        /* read high nibble first */
        lcd_e_high();
        lcd_e_delay();
        data = 0;
        if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x10;
        if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x20;
        if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x40;
        if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x80;
        lcd_e_low();
 
        lcd_e_delay();                       /* Enable 500ns low       */
 
        /* read low nibble */
        lcd_e_high();
        lcd_e_delay();
        if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x01;
        if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x02;
        if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x04;
        if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x08;
        lcd_e_low();
    }
    return data;
}
#else
#define lcd_read(rs) (rs) ? *(volatile uint8_t*)(LCD_IO_DATA+LCD_IO_READ) : *(volatile uint8_t*)(LCD_IO_FUNCTION+LCD_IO_READ)
/* rs==0 -> read instruction from LCD_IO_FUNCTION */
/* rs==1 -> read data from LCD_IO_DATA */
#endif
 
 
/*************************************************************************
loops while lcd is busy, returns address counter
*************************************************************************/
static uint8_t lcd_waitbusy(void)
 
{
    register uint8_t c;
 
    /* wait until busy flag is cleared */
    while ( (c=lcd_read(0)) & (1<<LCD_BUSY)) {}
 
    /* the address counter is updated 4us after the busy flag is cleared */
    delay(2);
 
    /* now read the address counter */
    return (lcd_read(0));  // return address counter
 
}/* lcd_waitbusy */
 
 
/*************************************************************************
Move cursor to the start of next line or to the first line if the cursor
is already on the last line.
*************************************************************************/
static inline void lcd_newline(uint8_t pos)
{
    register uint8_t addressCounter;
 
 
#if LCD_LINES==1
    addressCounter = 0;
#endif
#if LCD_LINES==2
    if ( pos < (LCD_START_LINE2) )
        addressCounter = LCD_START_LINE2;
    else
        addressCounter = LCD_START_LINE1;
#endif
#if LCD_LINES==4
    if ( pos < LCD_START_LINE3 )
        addressCounter = LCD_START_LINE2;
    else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE4) )
        addressCounter = LCD_START_LINE3;
    else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE2) )
        addressCounter = LCD_START_LINE4;
    else
        addressCounter = LCD_START_LINE1;
#endif
    lcd_command((1<<LCD_DDRAM)+addressCounter);
 
}/* lcd_newline */
 
 
/*
** PUBLIC FUNCTIONS
*/
 
/*************************************************************************
Send LCD controller instruction command
Input:   instruction to send to LCD controller, see HD44780 data sheet
Returns: none
*************************************************************************/
void lcd_command(uint8_t cmd)
{
    lcd_waitbusy();
    lcd_write(cmd,0);
}
 
 
/*************************************************************************
Set cursor to specified position
Input:    x  horizontal position  (0: left most position)
          y  vertical position    (0: first line)
Returns:  none
*************************************************************************/
void lcd_gotoxy(uint8_t x, uint8_t y)
{
#if LCD_LINES==1
    lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);
#endif
#if LCD_LINES==2
    if ( y==0 )
        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);
    else
        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x);
#endif
#if LCD_LINES==4
    if ( y==0 )
        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);
    else if ( y==1)
        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x);
    else if ( y==2)
        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE3+x);
    else /* y==3 */
        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE4+x);
#endif
 
}/* lcd_gotoxy */
 
 
/*************************************************************************
*************************************************************************/
int lcd_getxy(void)
{
    return lcd_waitbusy();
}
 
 
/*************************************************************************
Clear display and set cursor to home position
*************************************************************************/
void lcd_clrscr(void)
{
    lcd_command(1<<LCD_CLR);
}
 
 
/*************************************************************************
Set cursor to home position
*************************************************************************/
void lcd_home(void)
{
    lcd_command(1<<LCD_HOME);
}
 
 
/*************************************************************************
Display character at current cursor position
Input:    character to be displayed
Returns:  none
*************************************************************************/
void lcd_putc(char c)
{
    uint8_t pos;
 
 
    pos = lcd_waitbusy();   // read busy-flag and address counter
    if (c=='\n')
    {
        lcd_newline(pos);
    }
    else
    {
#if LCD_WRAP_LINES==1
#if LCD_LINES==1
        if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);
#elif LCD_LINES==2
        if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0);
        else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);
#elif LCD_LINES==4
        if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0);
        else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE3,0);
        else if ( pos == LCD_START_LINE3+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE4,0);
        else if ( pos == LCD_START_LINE4+LCD_DISP_LENGTH )
            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);
#endif
        lcd_waitbusy();
#endif
        lcd_write(c, 1);
    }
 
}/* lcd_putc */
 
 
/*************************************************************************
Display string without auto linefeed
Input:    string to be displayed
Returns:  none
*************************************************************************/
void lcd_puts(const char *s)
/* print string on lcd (no auto linefeed) */
{
    register char c;
 
    while ( (c = *s++) ) {
        lcd_putc(c);
    }
 
}/* lcd_puts */
 
 
/*************************************************************************
Display string from program memory without auto linefeed
Input:     string from program memory be be displayed
Returns:   none
*************************************************************************/
void lcd_puts_p(const char *progmem_s)
/* print string from program memory on lcd (no auto linefeed) */
{
    register char c;
 
    while ( (c = pgm_read_byte(progmem_s++)) ) {
        lcd_putc(c);
    }
 
}/* lcd_puts_p */
 
 
/*************************************************************************
Initialize display and select type of cursor
Input:    dispAttr LCD_DISP_OFF            display off
                   LCD_DISP_ON             display on, cursor off
                   LCD_DISP_ON_CURSOR      display on, cursor on
                   LCD_DISP_CURSOR_BLINK   display on, cursor on flashing
Returns:  none
*************************************************************************/
void lcd_init(uint8_t dispAttr)
{
#if LCD_IO_MODE
    /*
     *  Initialize LCD to 4 bit I/O mode
     */
 
    if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
      && ( &LCD_RS_PORT == &LCD_DATA0_PORT) && ( &LCD_RW_PORT == &LCD_DATA0_PORT) && (&LCD_E_PORT == &LCD_DATA0_PORT)
      && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3)
      && (LCD_RS_PIN == 4 ) && (LCD_RW_PIN == 5) && (LCD_E_PIN == 6 ) )
    {
        /* configure all port bits as output (all LCD lines on same port) */
        DDR(LCD_DATA0_PORT) |= 0x7F;
    }
    else if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )
           && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )
    {
        /* configure all port bits as output (all LCD data lines on same port, but control lines on different ports) */
        DDR(LCD_DATA0_PORT) |= 0x0F;
        DDR(LCD_RS_PORT)    |= _BV(LCD_RS_PIN);
        DDR(LCD_RW_PORT)    |= _BV(LCD_RW_PIN);
        DDR(LCD_E_PORT)     |= _BV(LCD_E_PIN);
    }
    else
    {
        /* configure all port bits as output (LCD data and control lines on different ports */
        DDR(LCD_RS_PORT)    |= _BV(LCD_RS_PIN);
        DDR(LCD_RW_PORT)    |= _BV(LCD_RW_PIN);
        DDR(LCD_E_PORT)     |= _BV(LCD_E_PIN);
        DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN);
        DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN);
        DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN);
        DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN);
    }
    delay(16000);        /* wait 16ms or more after power-on       */
 
    /* initial write to lcd is 8bit */
    LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);  // _BV(LCD_FUNCTION)>>4;
    LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);  // _BV(LCD_FUNCTION_8BIT)>>4;
    lcd_e_toggle();
    delay(4992);         /* delay, busy flag can't be checked here */
 
    /* repeat last command */
    lcd_e_toggle();
    delay(64);           /* delay, busy flag can't be checked here */
 
    /* repeat last command a third time */
    lcd_e_toggle();
    delay(64);           /* delay, busy flag can't be checked here */
 
    /* now configure for 4bit mode */
    LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);   // LCD_FUNCTION_4BIT_1LINE>>4
    lcd_e_toggle();
    delay(64);           /* some displays need this additional delay */
 
    /* from now the LCD only accepts 4 bit I/O, we can use lcd_command() */
#else
    /*
     * Initialize LCD to 8 bit memory mapped mode
     */
 
    /* enable external SRAM (memory mapped lcd) and one wait state */
    MCUCR = _BV(SRE) | _BV(SRW);
 
    /* reset LCD */
    delay(16000);                           /* wait 16ms after power-on     */
    lcd_write(LCD_FUNCTION_8BIT_1LINE,0);   /* function set: 8bit interface */
    delay(4992);                            /* wait 5ms                     */
    lcd_write(LCD_FUNCTION_8BIT_1LINE,0);   /* function set: 8bit interface */
    delay(64);                              /* wait 64us                    */
    lcd_write(LCD_FUNCTION_8BIT_1LINE,0);   /* function set: 8bit interface */
    delay(64);                              /* wait 64us                    */
#endif
    lcd_command(LCD_FUNCTION_DEFAULT);      /* function set: display lines  */
    lcd_command(LCD_DISP_OFF);              /* display off                  */
    lcd_clrscr();                           /* display clear                */
    lcd_command(LCD_MODE_DEFAULT);          /* set entry mode               */
    lcd_command(dispAttr);                  /* display/cursor control       */
 
}/* lcd_init */

lcd.h

#ifndef LCD_H
#define LCD_H
/*************************************************************************
 Title	:   C include file for the HD44780U LCD library (lcd.c)
 Author:    Peter Fleury <pfleury@gmx.ch>  http://jump.to/fleury
 File:	    $Id: lcd.h,v 1.12.2.2 2004/02/12 21:05:59 peter Exp $
 Software:  AVR-GCC 3.3
 Hardware:  any AVR device, memory mapped mode only for AT90S4414/8515/Mega
***************************************************************************/
 
/**
 @defgroup pfleury_lcd LCD library
 @code #include <lcd.h> @endcode
 
 @brief Basic routines for interfacing a HD44780U-based text LCD display
 
 Originally based on Volker Oth's LCD library,
 changed lcd_init(), added additional constants for lcd_command(),
 added 4-bit I/O mode, improved and optimized code.
 
 Library can be operated in memory mapped mode (LCD_IO_MODE=0) or in
 4-bit IO port mode (LCD_IO_MODE=1). 8-bit IO port mode not supported.
 
 Memory mapped mode compatible with Kanda STK200, but supports also
 generation of R/W signal through A8 address line.
 
 @author Peter Fleury pfleury@gmx.ch http://jump.to/fleury
 
 @see The chapter <a href="http://homepage.sunrise.ch/mysunrise/pfleury/avr-lcd44780.html" target="_blank">Interfacing a HD44780 Based LCD to an AVR</a>
      on my home page.
 
*/
 
/*@{*/
 
#if (__GNUC__ * 100 + __GNUC_MINOR__) < 303
#error "This library requires AVR-GCC 3.3 or later, update to newer AVR-GCC compiler !"
#endif
 
#include <inttypes.h>
#include <avr/pgmspace.h>
 
/**
 *  @name  Definitions for MCU Clock Frequency
 *  Adapt the MCU clock frequency in Hz to your target.
 */
#define XTAL 8000000              /**< clock frequency in Hz, used to calculate delay timer */
//#define F_CPU 8000000UL
/**
 *  @name  Definitions for Display Size
 *  Change these definitions to adapt setting to your display
 */
#define LCD_LINES           2     /**< number of visible lines of the display */
#define LCD_DISP_LENGTH    16     /**< visibles characters per line of the display */
#define LCD_LINE_LENGTH  0x10     /**< internal line length of the display    */
#define LCD_START_LINE1  0x00     /**< DDRAM address of first char of line 1 */
#define LCD_START_LINE2  0x40     /**< DDRAM address of first char of line 2 */
#define LCD_START_LINE3  0x14     /**< DDRAM address of first char of line 3 */
#define LCD_START_LINE4  0x54     /**< DDRAM address of first char of line 4 */
#define LCD_WRAP_LINES      0     /**< 0: no wrap, 1: wrap at end of visibile line */
 
 
#define LCD_IO_MODE      1         /**< 0: memory mapped mode, 1: IO port mode */
#if LCD_IO_MODE
/**
 *  @name Definitions for 4-bit IO mode
 *  Change LCD_PORT if you want to use a different port for the LCD pins.
 *
 *  The four LCD data lines and the three control lines RS, RW, E can be on the
 *  same port or on different ports.
 *  Change LCD_RS_PORT, LCD_RW_PORT, LCD_E_PORT if you want the control lines on
 *  different ports.
 *
 *  Normally the four data lines should be mapped to bit 0..3 on one port, but it
 *  is possible to connect these data lines in different order or even on different
 *  ports by adapting the LCD_DATAx_PORT and LCD_DATAx_PIN definitions.
 *
 */
 
#define LCD_DATA0_PORT   PORTB     /**< port for 4bit data bit 0 */
#define LCD_DATA0_PIN    0            /**< pin for 4bit data bit 0  */
 
#define LCD_DATA1_PORT   PORTD     /**< port for 4bit data bit 1 */
#define LCD_DATA1_PIN    6            /**< pin for 4bit data bit 1  */
 
#define LCD_DATA2_PORT   PORTB     /**< port for 4bit data bit 2 */
#define LCD_DATA2_PIN    1            /**< pin for 4bit data bit 2  */
 
#define LCD_DATA3_PORT   PORTB     /**< port for 4bit data bit 3 */
#define LCD_DATA3_PIN    2            /**< pin for 4bit data bit 3  */
 
 
#define LCD_RS_PORT      PORTB     /**< port for RS line         */
#define LCD_RS_PIN       7            /**< pin  for RS line         */
 
#define LCD_RW_PORT      PORTB     /**< port for RW line         */
#define LCD_RW_PIN       6            /**< pin  for RW line         */
 
#define LCD_E_PORT       PORTB     /**< port for Enable line     */
#define LCD_E_PIN        5            /**< pin  for Enable line     */
 
 
#elif defined(__AVR_AT90S4414__) || defined(__AVR_AT90S8515__) || defined(__AVR_ATmega64__) || \
      defined(__AVR_ATmega8515__)|| defined(__AVR_ATmega103__) || defined(__AVR_ATmega128__) || \
      defined(__AVR_ATmega161__) || defined(__AVR_ATmega162__)
/*
 *  memory mapped mode is only supported when the device has an external data memory interface
 */
#define LCD_IO_DATA      0xC000    /* A15=E=1, A14=RS=1                 */
#define LCD_IO_FUNCTION  0x8000    /* A15=E=1, A14=RS=0                 */
#define LCD_IO_READ      0x0100    /* A8 =R/W=1 (R/W: 1=Read, 0=Write   */
#else
#error "external data memory interface not available for this device, use 4-bit IO port mode"
 
#endif
 
 
/**
 *  @name Definitions for LCD command instructions
 *  The constants define the various LCD controller instructions which can be passed to the
 *  function lcd_command(), see HD44780 data sheet for a complete description.
 */
 
/* instruction register bit positions, see HD44780U data sheet */
#define LCD_CLR               0      /* DB0: clear display                  */
#define LCD_HOME              1      /* DB1: return to home position        */
#define LCD_ENTRY_MODE        2      /* DB2: set entry mode                 */
#define LCD_ENTRY_INC         1      /*   DB1: 1=increment, 0=decrement     */
#define LCD_ENTRY_SHIFT       0      /*   DB2: 1=display shift on           */
#define LCD_ON                3      /* DB3: turn lcd/cursor on             */
#define LCD_ON_DISPLAY        2      /*   DB2: turn display on              */
#define LCD_ON_CURSOR         1      /*   DB1: turn cursor on               */
#define LCD_ON_BLINK          0      /*     DB0: blinking cursor ?          */
#define LCD_MOVE              4      /* DB4: move cursor/display            */
#define LCD_MOVE_DISP         3      /*   DB3: move display (0-> cursor) ?  */
#define LCD_MOVE_RIGHT        2      /*   DB2: move right (0-> left) ?      */
#define LCD_FUNCTION          5      /* DB5: function set                   */
#define LCD_FUNCTION_8BIT     4      /*   DB4: set 8BIT mode (0->4BIT mode) */
#define LCD_FUNCTION_2LINES   3      /*   DB3: two lines (0->one line)      */
#define LCD_FUNCTION_10DOTS   2      /*   DB2: 5x10 font (0->5x7 font)      */
#define LCD_CGRAM             6      /* DB6: set CG RAM address             */
#define LCD_DDRAM             7      /* DB7: set DD RAM address             */
#define LCD_BUSY              7      /* DB7: LCD is busy                    */
 
/* set entry mode: display shift on/off, dec/inc cursor move direction */
#define LCD_ENTRY_DEC            0x04   /* display shift off, dec cursor move dir */
#define LCD_ENTRY_DEC_SHIFT      0x05   /* display shift on,  dec cursor move dir */
#define LCD_ENTRY_INC_           0x06   /* display shift off, inc cursor move dir */
#define LCD_ENTRY_INC_SHIFT      0x07   /* display shift on,  inc cursor move dir */
 
/* display on/off, cursor on/off, blinking char at cursor position */
#define LCD_DISP_OFF             0x08   /* display off                            */
#define LCD_DISP_ON              0x0C   /* display on, cursor off                 */
#define LCD_DISP_ON_BLINK        0x0D   /* display on, cursor off, blink char     */
#define LCD_DISP_ON_CURSOR       0x0E   /* display on, cursor on                  */
#define LCD_DISP_ON_CURSOR_BLINK 0x0F   /* display on, cursor on, blink char      */
 
/* move cursor/shift display */
#define LCD_MOVE_CURSOR_LEFT     0x10   /* move cursor left  (decrement)          */
#define LCD_MOVE_CURSOR_RIGHT    0x14   /* move cursor right (increment)          */
#define LCD_MOVE_DISP_LEFT       0x18   /* shift display left                     */
#define LCD_MOVE_DISP_RIGHT      0x1C   /* shift display right                    */
 
/* function set: set interface data length and number of display lines */
#define LCD_FUNCTION_4BIT_1LINE  0x20   /* 4-bit interface, single line, 5x7 dots */
#define LCD_FUNCTION_4BIT_2LINES 0x28   /* 4-bit interface, dual line,   5x7 dots */
#define LCD_FUNCTION_8BIT_1LINE  0x30   /* 8-bit interface, single line, 5x7 dots */
#define LCD_FUNCTION_8BIT_2LINES 0x38   /* 8-bit interface, dual line,   5x7 dots */
 
 
#define LCD_MODE_DEFAULT     ((1<<LCD_ENTRY_MODE) | (1<<LCD_ENTRY_INC) )
 
 
 
/**
 *  @name Functions
 */
 
 
/**
 @brief    Initialize display and select type of cursor
 @param    dispAttr \b LCD_DISP_OFF display off\n
                    \b LCD_DISP_ON display on, cursor off\n
                    \b LCD_DISP_ON_CURSOR display on, cursor on\n
                    \b LCD_DISP_ON_CURSOR_BLINK display on, cursor on flashing
 @return  none
*/
extern void lcd_init(uint8_t dispAttr);
 
 
/**
 @brief    Clear display and set cursor to home position
 @param    void
 @return   none
*/
extern void lcd_clrscr(void);
 
 
/**
 @brief    Set cursor to home position
 @param    void
 @return   none
*/
extern void lcd_home(void);
 
 
/**
 @brief    Set cursor to specified position
 
 @param    x horizontal position\n (0: left most position)
 @param    y vertical position\n   (0: first line)
 @return   none
*/
extern void lcd_gotoxy(uint8_t x, uint8_t y);
 
 
/**
 @brief    Display character at current cursor position
 @param    c character to be displayed
 @return   none
*/
extern void lcd_putc(char c);
 
 
/**
 @brief    Display string without auto linefeed
 @param    s string to be displayed
 @return   none
*/
extern void lcd_puts(const char *s);
 
 
/**
 @brief    Display string from program memory without auto linefeed
 @param    s string from program memory be be displayed
 @return   none
 @see      lcd_puts_P
*/
extern void lcd_puts_p(const char *progmem_s);
 
 
/**
 @brief    Send LCD controller instruction command
 @param    cmd instruction to send to LCD controller, see HD44780 data sheet
 @return   none
*/
extern void lcd_command(uint8_t cmd);
 
 
/**
 @brief macros for automatically storing string constant in program memory
*/
#define lcd_puts_P(__s)         lcd_puts_p(PSTR(__s))
 
/*@}*/
#endif //LCD_H