want an lcd interfacing program for attiny2313

thannara123 · Dec 17, 2012

want an lcd interfacing program in c
want to interface prot PD .(Because of it 7 bit how data sent ?)
PD0,PD1,and PD2 uses as rs,rw,e respectively
then PD3,PD4,PD5,andPD6 for data or command
How can i program please any one help ?

alexan_e · Dec 17, 2012

There are several LCD libraries you can download and use without having to bother about all the internal LCD parameters.

Try this library **broken link removed**
it is one of the well knows libraries for AVR.

Copy the files in the project folder and change the header to reflect your settings

thannara123 · Dec 17, 2012

but how t send data as 4bit to port PD3,PD4,PD5,and PD6 . How to send the specified port (PD3,PD4,PD5,andPD6). I am new to in AVR .can i get an example ?.

alexan_e · Dec 17, 2012

You don't have to do anything about that, the LCD functions will take care of it, just set the library header to use the correct port pins.

There is an example in the library zip file that shows how the library is used

Create a project and if you can't make it work attach it here

bigdogguru · Dec 17, 2012

thannara123 said:
but how t send data as 4bit to port PD3,PD4,PD5,and PD6 . How to send the specified port (PD3,PD4,PD5,andPD6). I am new to in AVR .can i get an example ?.

The following is a good example of an LCD 4-bit and 8-bit interface with an ATtiny2313:

8 bit and 4 bit LCD interfacing with ATtiny

BigDog

- - - Updated - - -

Another tutorial:

LCD @ AVR

BigDog

thannara123 · Dec 17, 2012

Code:

//#define F_CPU 12000000UL
#include<avr/io.h>
#include<util/delay.h>
#include<inttypes.h>
 
#define rs PA0    
#define rw PA1
#define en PA2
 
void lcd_init();
void dis_cmd(char);
void dis_data(char);
void lcdcmd(char);
void lcddata(char);
 
int main(void)
{
    unsigned char data0[11]="ENGINEERS";
    unsigned char data1[10]="GARAGE";
 
    int i=0;
    DDRA=0xFF;
    lcd_init();             
    
    while(data0[i]!='\0')
    {
        dis_data(data0[i]);
        _delay_ms(200);
        i++;
    }
 
    dis_cmd(0xC5);
 
    i=0;
    while(data1[i]!='\0')
    {
        dis_data(data1[i]);
        _delay_ms(200);
        i++;
    }
 
    while(1);
}
 
 
 
void lcd_init()    // fuction for intialize 
{
    dis_cmd(0x02);        // to initialize LCD in 4-bit mode.
    dis_cmd(0x28);        //to initialize LCD in 2 lines, 5X7 dots and 4bit mode.
    dis_cmd(0x0C);
    dis_cmd(0x06);
    dis_cmd(0x83);
}
 
void dis_cmd(char cmd_value)
{
    char cmd_value1;
    
    cmd_value1 = cmd_value & 0xF0;        //mask lower nibble because PA4-PA7 pins are used. 
    lcdcmd(cmd_value1);            // send to LCD
 
    cmd_value1 = ((cmd_value<<4) & 0xF0);    //shift 4-bit and mask
    lcdcmd(cmd_value1);            // send to LCD
}                        
 
 
void dis_data(char data_value)
{
    char data_value1;
    
    data_value1=data_value&0xF0;
    lcddata(data_value1);
 
    data_value1=((data_value<<4)&0xF0);
    lcddata(data_value1);
}
 
void lcdcmd(char cmdout)
{
    PORTA=cmdout;
    PORTA&=~(1<<rs);
    PORTA&=~(1<<rw);
    PORTA|=(1<<en);
    _delay_ms(1);
    PORTA&=~(1<<en);
}
 
void lcddata(char dataout)
{
    PORTA=dataout;
    PORTA|=(1<<rs);
    PORTA&=~(1<<rw);
    PORTA|=(1<<en);
    _delay_ms(1);
    PORTA&=~(1<<en);
}

my i get help , to change the port for as i said above ?

alexan_e · Dec 17, 2012

I don't like this implementation , the port is hard-coded in the functions.
If you want to use it change PORTA in the last two functions to the PORT you want to use

bigdogguru · Dec 17, 2012

Why not use Joonas' example code:

Code:

// Control 16 character LCD (2x8 chars) with 4 bit interface
// Copyright (C) 2012 Joonas Pihlajamaa. Released to public domain.
// No warranties, use at your own responsibility.

#include <avr/io.h>

#define F_CPU 12000000UL // 12 MHz
#include <util/delay.h>

#define DATA_PORT_DIR DDRB
#define DATA_PORT PORTB
#define DATA_PORT_IN PINB

#define RW_PIN (1<<PD4)
#define RS_PIN (1<<PD5)
#define EN_PIN (1<<PD6)

#define SET_CTRL_BIT(pin) (PORTD |= pin)
#define CLEAR_CTRL_BIT(pin) (PORTD &= ~pin)

// assumes EN_PIN is LOW in the beginning
void lcd_write_nibble(char rs, unsigned char data) {
    if(DATA_PORT_DIR != 0xF)
        DATA_PORT_DIR = 0xF;
        
    CLEAR_CTRL_BIT(RW_PIN);
    
    if(rs)
        SET_CTRL_BIT(RS_PIN);
    else
        CLEAR_CTRL_BIT(RS_PIN); 
        
    DATA_PORT = data;
    
    _delay_us(2);
    SET_CTRL_BIT(EN_PIN);
    _delay_us(2);
    CLEAR_CTRL_BIT(EN_PIN);
}

void lcd_write_byte(char rs, unsigned char data) {
    lcd_write_nibble(rs, data >> 4);
    lcd_write_nibble(rs, data & 0xF);
}

unsigned char lcd_read_nibble(char rs) {
    unsigned char data;
    
    if(DATA_PORT_DIR != 0)
        DATA_PORT_DIR = 0;
        
    SET_CTRL_BIT(RW_PIN);
    
    if(rs)
        SET_CTRL_BIT(RS_PIN);
    else
        CLEAR_CTRL_BIT(RS_PIN); 
        
    _delay_us(2);
    SET_CTRL_BIT(EN_PIN);
    _delay_us(2);
    data = DATA_PORT_IN & 0xF;
    CLEAR_CTRL_BIT(EN_PIN);
    
    return data;
}

unsigned char lcd_read_byte(char rs) {
    unsigned char data;

    data = lcd_read_nibble(rs) << 4;
    data += lcd_read_nibble(rs) & 0xF;
    
    return data;
}

void lcd_wait() {
    while(lcd_read_byte(0) & 0x80); // wait until display is ready
}

void lcd_init() {
    _delay_ms(50); // wait for VDD to rise
    lcd_write_nibble(0, 0x3);
    _delay_ms(5);
    lcd_write_nibble(0, 0x3);
    _delay_ms(1);
    lcd_write_nibble(0, 0x2); // 4-bit mode
    _delay_ms(1);

    lcd_write_byte(0, 0x28); // 2 lines, normal font
    _delay_ms(1);
    lcd_write_byte(0, 0xC); // display on
    _delay_ms(1);
    lcd_write_byte(0, 1); // display clear
    _delay_ms(1);
    lcd_write_byte(0, 0x6); // increment, don't shift
    _delay_ms(1);    
}

void lcd_puts(char * string) {
    char i;
    
    lcd_write_byte(0, 0x80); // move to 1st line
    lcd_wait();
    
    for(i=0; i<8; i++) {
        if(string[i] == '\0')
            return;
            
        lcd_write_byte(1, string[i]);
        lcd_wait();
    }
    
    lcd_write_byte(0, 0x80+0x40); // move to 2nd line
    lcd_wait();
    
    for(i=8; i<16; i++) {
        if(string[i] == '\0')
            return;
            
        lcd_write_byte(1, string[i]);
        lcd_wait();
    }
}

int main(void) {
    unsigned char i = 0;
    char message[] = "nn Mississippi..";
    
    DDRD = RS_PIN + EN_PIN + RW_PIN; // Control outputs
    DDRB = 0xF; // PB0..PB3 as DB4..DB7
	    
    lcd_init();
    
    lcd_puts("Hello, 4-bit LCD!");
    
    _delay_ms(2000);
        
	while(1) {
        if(++i >= 100)
            i = 1;
            
        if(i >= 10)
            message[0] = i/10+'0';
        else
            message[0] = ' ';
        message[1] = i%10+'0';
        
        lcd_puts(message);
        _delay_ms(1000);
    } 

	return 1;
}

BigDog

thannara123 · Dec 17, 2012

for example

PORTA=dataout; changed as PORTD = dataout ;
here the dataout will sent to the PORTD
But sir the PORT D havent 8 bit it is 7 bit then how ?
(PD0,PD1,and PD2 uses as rs,rw,e respectively )

alexan_e · Dec 17, 2012

The library you chose uses for data bits 7:3 of the selected port, the only way to change that is to modify the functions

bigdogguru · Dec 17, 2012

I also came across this 4-bit adaptation of the winAVR lcd library:

The header file looks reasonably easily to modify:

Code:

//*****************************************************************************
//
// File Name	: 'lcd_lib.h'
// Title		: 4 bit LCd interface header file
// Author		: Scienceprog.com - Copyright (C) 2007
// Created		: 2007-06-18
// Revised		: 2007-06-18
// Version		: 1.0
// Target MCU	: Atmel AVR series
//
// This code is distributed under the GNU Public License
//		which can be found at [url]https://www.gnu.org/licenses/gpl.txt[/url]
//
//*****************************************************************************
#ifndef LCD_LIB
#define LCD_LIB

#include <inttypes.h>

#define LCD_RS	0 	//define MCU pin connected to LCD RS
#define LCD_RW	1 	//define MCU pin connected to LCD R/W
#define LCD_E	2	//define MCU pin connected to LCD E
#define LCD_D4	4	//define MCU pin connected to LCD D3
#define LCD_D5	5	//define MCU pin connected to LCD D4
#define LCD_D6	6	//define MCU pin connected to LCD D5
#define LCD_D7	7	//define MCU pin connected to LCD D6
#define LDP PORTD	//define MCU port connected to LCD data pins
#define LCP PORTD	//define MCU port connected to LCD control pins
#define LDDR DDRD	//define MCU direction register for port connected to LCD data pins
#define LCDR DDRD	//define MCU direction register for port connected to LCD control pins

#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: increment
#define LCD_ENTRY_SHIFT     0	//DB2: shift
#define LCD_ON_CTRL         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-> move 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
// reading:
#define LCD_BUSY            7	//DB7: LCD is busy
#define LCD_LINES			2	//visible lines
#define LCD_LINE_LENGTH		16	//line length (in characters)
// cursor position to DDRAM mapping
#define LCD_LINE0_DDRAMADDR		0x00
#define LCD_LINE1_DDRAMADDR		0x40
#define LCD_LINE2_DDRAMADDR		0x14
#define LCD_LINE3_DDRAMADDR		0x54

void LCDsendChar(uint8_t);		//forms data ready to send to 74HC164
void LCDsendCommand(uint8_t);	//forms data ready to send to 74HC164
void LCDinit(void);			//Initializes LCD
void LCDclr(void);				//Clears LCD
void LCDhome(void);			//LCD cursor home
void LCDstring(uint8_t*, uint8_t);	//Outputs string to LCD
void LCDGotoXY(uint8_t, uint8_t);	//Cursor to X Y position
void CopyStringtoLCD(const uint8_t*, uint8_t, uint8_t);//copies flash string to LCD at x,y
void LCDdefinechar(const uint8_t *,uint8_t);//write char to LCD CGRAM 
void LCDshiftRight(uint8_t);	//shift by n characters Right
void LCDshiftLeft(uint8_t);	//shift by n characters Left
void LCDcursorOn(void);		//Underline cursor ON
void LCDcursorOnBlink(void);	//Underline blinking cursor ON
void LCDcursorOFF(void);		//Cursor OFF
void LCDblank(void);			//LCD blank but not cleared
void LCDvisible(void);			//LCD visible
void LCDcursorLeft(uint8_t);	//Shift cursor left by n
void LCDcursorRight(uint8_t);	//shif cursor right by n

#endif

BigDog

thannara123 · Dec 17, 2012

thanks i got finally all...

want an lcd interfacing program for attiny2313

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