Giao tiếp LCD với avr atmega8 bằng 3 dây tín hiệu sử dụng 74hc595

Giao tiếp LCD với avr atmega8 bằng 3 dây tín hiệu sử dụng 74hc595

Code trình biên dịch atmelstudio 6.0

#include <util/delay.h>

#define sbi(sfr,bit) sfr|=_BV(bit)

#define cbi(sfr,bit) sfr&=~(_BV(bit))

#define EN                            2

#define RW                           1

#define RS                            0

#define CTRL                       PORTB

#define DDR_CTRL             DDRB

int DATA_O=0;//                  PORTB

#define DATA_I                    PINB

#define DDR_DATA             DDRB

/*

#define LCD8BIT

#define DATA_O                  PORTD

#define DATA_I                    PIND

#define DDR_DATA             DDRD

*/

#define hc PORTD

#define data 6

#define sck 5

#define src 7

unsigned char i;

void nap()

{

cbi(hc,sck);

sbi(hc,sck);

}

void chot()

{

cbi(hc,src);

sbi(hc,src);

}

void bit(int i)

{

if (i==1) sbi(hc,data);

if (i==0) cbi(hc,data);

}

int xuat595(int n)

{

int bien;

for (i=0;i<=7;i++)

{

bien=n&0x80;

if (bien==0)

{

cbi(hc,data);

}

else sbi(hc,data);

nap();

n=n<<1;

}

chot();

}

int sbi595(int dt ,int bi){

dt|=(1<<bi);

DATA_O=dt;

xuat595(DATA_O);

}

int cbi595(char dt ,char bi){

dt&=~(1<<bi);

DATA_O=dt;

xuat595(DATA_O);

}

/*char Read2Nib(){

char HNib, LNib;

DATA_O |=0xF0;

sbi(CTRL,EN); //enable

DDR_DATA &=0x0F; //set 4 bits cao cua PORT DATA lam input

HNib=DATA_I & 0xF0;

cbi(CTRL,EN); //disable

sbi(CTRL,EN); //enable

LNib = DATA_I & 0xF0;

cbi(CTRL,EN); //disable

LNib>>=4;

return (HNib|LNib);

}*/

void Write2Nib(uint8_t chr){

uint8_t HNib, LNib, temp_data;

temp_data=DATA_O & 0x0F; //doc 4 bit thap cua DATA_O de mask,

HNib=chr & 0xF0;

LNib=(chr<<4) & 0xF0;

DATA_O =(HNib |temp_data);

xuat595(DATA_O);

sbi595(DATA_O,EN); //enable

cbi595(DATA_O,EN); //disable

DATA_O =(LNib|temp_data);

xuat595(DATA_O);

sbi595(DATA_O,EN); //enable

cbi595(DATA_O,EN); //disable

}

void Write8Bit(uint8_t chr){

DATA_O=chr;   //out 8 bits to DATA Line

xuat595(DATA_O);

sbi595(DATA_O,EN); //enable

cbi595(DATA_O,EN); //disable

}

void wait_LCD(){

_delay_ms(2);

}

void init_LCD()

{

//Function set------------------------------------------------------------------------------

cbi595(DATA_O,RS);   // the following data is COMMAND

cbi595(DATA_O, EN);

sbi595(DATA_O,EN); //enable

sbi595(DATA_O, 5);

cbi595(DATA_O,EN); //disable

wait_LCD();

Write2Nib(0x28);//4 bit mode, 2 line, 5x8 font

wait_LCD();

//Display control-------------------------------------------------------------------------

cbi595(DATA_O,RS); // the following data is COMMAND

Write2Nib(0x0C);

wait_LCD();

//Entry mode set------------------------------------------------------------------------

cbi595(DATA_O,RS); // the following data is COMMAND

Write2Nib(0x06);

wait_LCD();

}

void home_LCD()

{

cbi595(DATA_O,RS); // the following data is COMMAND

Write2Nib(0x02);

wait_LCD();

}

void move_LCD(uint8_t y,uint8_t x)

{

uint8_t Ad;

Ad=64*(y-1)+(x-1)+0x80; // tính mã l?nh

cbi595(DATA_O,RS); // the following data is COMMAND

Write2Nib(Ad);

wait_LCD();

}

void clr_LCD(){ //xóa toàn b? LCD

cbi595(DATA_O,RS); //RS=0 mean the following data is COMMAND (not normal DATA)

Write2Nib(0x01);

wait_LCD();

}

void putChar_LCD(uint8_t chr){ //hi?n th? 1 ký t? chr lên LCD

sbi595(DATA_O,RS); //this is a normal DATA

Write2Nib(chr);

wait_LCD();

}

void print_LCD(char* str, unsigned char len){ //Hiển thị 1 chuỗi ký tự

       unsigned char i;

       for (i=0; i<len; i++){

              if(str[i] > 0) putChar_LCD(str[i]);

             else putChar_LCD(' ');

       }

}