LCD Library for AVR Atmega32

[Shishir K Chakravarthy]

//An LCD library for interfacing Atmega 32 to a 16X2 LCD…

//Author: Shishir K Chakravarthy ~Blitz

//Interface manual:

//Enable –>           PORTD PIN0

//Register Select –>  PORTD PIN1

//Read/Write –>       PORTD PIN2

//D0 –> PORTB PIN0 |         

//D1 –> PORTB PIN1   |

//D2 –> PORTB PIN2 |

//D3 –> PORTB PIN3 | for 8 bit data

//D4 –> PORTB PIN4 |

//D5 –> PORTB PIN5 |

//D6 –> PORTB PIN6 |

//D7 –> PORTB PIN7 |

//Commands :

//LCD_INIT(); –> Initializes the LCD for Display PS:Cursor OFF

//LCD_WRITE(“string”); –> To display characters

//LCD_WRITE_NUM(value,width); –>To display number of specified width

//LCD_SETCURSOR(x,y); –>To set cursor coordinates

//LCD_CLEAR(); –>Erases LCD memory

//Enjoy!!!

 

 

#ifndef m32_16X2_LCD_H_

#define m32_16X2_LCD_H_

 

#include <avr/io.h>

#include <util/delay.h>

#include <stdlib.h>

 

#define DATADIR_PORTB DDRB

#define DATADIR_PORTD DDRD

#define LCD_CONTROL PORTD

#define LCD_DT PORTB

#define EN PIND0

#define RS PIND1

#define RW PIND2

 

void LCD_INIT();

void LCD_CMD(unsigned char);

void LCD_DATA(unsigned char);

void LCD_WRITE(char *string);

void LCD_WRITE_NUM(unsigned char, unsigned char);

void LCD_SETCURSOR(uint8_t, uint8_t);

void LCD_CLEAR();

void LCD_BUSY_CHECK();

void LCD_FLASH();

 

unsigned char InitColumn[2]={0,64};

 

void LCD_INIT()

{

DATADIR_PORTD |= (1<<EN|1<<RS|1<<RW);

DATADIR_PORTB = 0xFF;

_delay_ms(20);

 

LCD_CMD(0x01);

_delay_ms(2);

LCD_CMD(0x38);

_delay_us(50);

LCD_CMD(0x0C);

_delay_us(50);

LCD_CMD(0x06);

_delay_us(50);

}

 

void LCD_CMD(unsigned char cmd)

{

LCD_CHECK_BUSY();

LCD_DT = cmd;

LCD_CONTROL &=~((1<<RW)|(1<<RS));

LCD_FLASH();

LCD_DT = 0;

}

 

void LCD_DATA(unsigned char data)

{

LCD_CHECK_BUSY();

LCD_DT = data;

LCD_CONTROL &=~(1<<RW);

LCD_CONTROL |=1<<RS;

LCD_FLASH();

LCD_DT = 0;

}

 

void LCD_WRITE(char *string)

{

while(*string>0)

{

LCD_DATA(*string++);

_delay_us(50);

}

}

 

void LCD_WRITE_NUM(unsigned char val, unsigned char width)

{

unsigned char array[width];

itoa(val,array,10);

LCD_WRITE(array);

_delay_us(50);

}

 

void LCD_SETCURSOR(uint8_t x, uint8_t y)

{

LCD_CMD(0x80 + InitColumn[y] + x);

_delay_us(50);

}

 

void LCD_CLEAR()

{

LCD_CMD(0x01);

_delay_us(50);

}

 

void LCD_CHECK_BUSY()

{

DATADIR_PORTB = 0;

LCD_CONTROL |= 1<<RW;

LCD_CONTROL &=~(1<<RS);

 

while(LCD_DT >=0x80)

{

LCD_FLASH();

}

DATADIR_PORTB = 0xFF;

}

 

void LCD_FLASH()

{

LCD_CONTROL |=1<<EN;

asm volatile(“nop”);

asm volatile(“nop”);

LCD_CONTROL &=~(1<<EN);

}

 

#endif /*m32_16X2_LCD_H_*/

 

 

[AJISH ALFRED]

Nice, and thanks for sharing.

[Author]

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