lcd.c (LCD16x2-Showtime)

#include <stdlib.h>
#include <ctype.h>
#include "lcd.h" //Cau hinh ket noi va khai bao lenh dung cho LCD.
void lcd_init()
{
    //Khai bao bien.
    unsigned char i;
    //Dinh nghia ham.
    LCD_EN_TRIS=0; //Cau hinh ngo ra cac duong dieu khien.
    LCD_RS_TRIS=0;
    LCD_RW_TRIS=0;
    LCD_DATA4_TRIS=0; //Cau hinh ngo ra cho cac duong du lieu.
    LCD_DATA5_TRIS=0;
    LCD_DATA6_TRIS=0;
    LCD_DATA7_TRIS=0;
    LCD_EN=0; //EN=0 - Disable.
    LCD_RS=0; //RS=0 - Command.
    LCD_RW=0; //RW=0 - Write.
    __delay_ms(100); //Tao thoi gian tre khi bat nguon cho LCD.
    //Reset LCD.
    lcd_put_byte(0,0x30);
    __delay_ms(50);
    lcd_put_byte(0,0x30);
    __delay_ms(50);
    lcd_put_byte(0,0x32);
    __delay_ms(100); //Tao tre de reset LCD.
    __delay_ms(100);
    __delay_ms(100);
    while(lcd_busy());
    lcd_put_byte(0,FOUR_BIT&LINES_5X7); //Thiet lap loai LCD.
    while(lcd_busy());
    lcd_put_byte(0,DOFF&CURSOR_OFF&BLINK_OFF); //Tat hien thi.
    while(lcd_busy());
    lcd_put_byte(0,DON&CURSOR_OFF&BLINK_OFF); //Bat hien thi.
    while(lcd_busy());
    lcd_put_byte(0,0x01); //Xoa hien thi va di chuyen con tro ve dau dong.
    while(lcd_busy());
    lcd_put_byte(0,SHIFT_CUR_LEFT); //Che do dich chuyen con tro.
    while(lcd_busy());
    lcd_put_byte(0,0x01); //Xoa hien thi va di chuyen con tro ve dau dong.
    while(lcd_busy());
}
unsigned char lcd_busy()
{
    //Khai bao bien.
    unsigned char busy;
    //Dinh nghia ham.
    LCD_DATA4_TRIS=1; //Cau hinh ngo vao cho cac duong du lieu.
    LCD_DATA5_TRIS=1;
    LCD_DATA6_TRIS=1;
    LCD_DATA7_TRIS=1;
    LCD_RW=1; //RW=1 - Read.
    LCD_RS=0; //RS=0 - Command.
    __delay_us(20);
    LCD_EN=1; //EN=1 - Enable.
    __delay_us(20);
    busy=LCD_DATA7; //Doc gia tri co bao ban tu LCD.
    LCD_EN=0; //EN=0 - Disable.
    __delay_us(20);
    LCD_EN=1; //EN=1 - Enable. Tao xung truyen thong tin.
    __delay_us(20);
    LCD_EN=0; //EN=0 - Disable.
    return busy; //Tra ve gia tri bao LCD ban hay khong (1: Busy).
}
unsigned char lcd_get_byte(unsigned char rs)
{
    //Khai bao bien.
    BYTE_VAL b; //Bien chua gia tri doc ve tu LCD.
    //Dinh nghia ham.
    LCD_DATA4_TRIS=1; //Cau hinh ngo vao cho cac duong du lieu.
    LCD_DATA5_TRIS=1;
    LCD_DATA6_TRIS=1;
    LCD_DATA7_TRIS=1;
    LCD_RW=1; //RW=1 - Read.
    LCD_RS=0; //RS=0 - Command. Mac dinh la doc Command.
    if (rs) LCD_RS=1; //Kiem tra yeu cau doc Data (rs=1) hay doc Command (rs=0).
    //RS=1 - Data. Neu chon lua doc Data.
    __delay_us(20);
    LCD_EN=1; //EN=1 - Enable. Doc 4 bit cao cua thong tin can doc tu LCD.
    __delay_us(20);
    b.bits.b7=LCD_DATA7; //Doc 4 bit cao.
    b.bits.b6=LCD_DATA6;
    b.bits.b5=LCD_DATA5;
    b.bits.b4=LCD_DATA4;
    LCD_EN=0; //EN=0 - Disable.
    __delay_us(20);
    LCD_EN=1; //EN=1 - Enable. Doc 4 bit thap cua thong tin can doc tu LCD.
    __delay_us(20);
    b.bits.b3=LCD_DATA7; //Doc 4 bit thap.
    b.bits.b2=LCD_DATA6;
    b.bits.b1=LCD_DATA5;
    b.bits.b0=LCD_DATA4;
    LCD_EN=0; //EN=0 - Disable.
    return b.Val; //Tra ve gia tri doc duoc tu LCD (8 bit).
}
void lcd_put_byte(unsigned char rs,unsigned char b)
{
    //Khai bao bien.
    BYTE_VAL temp; //Bien luu tam thong tin.
    //Dinh nghia ham.
    LCD_DATA4_TRIS=0; //Cau hinh ngo ra cho cac duong du lieu.
    LCD_DATA5_TRIS=0;
    LCD_DATA6_TRIS=0;
    LCD_DATA7_TRIS=0;
    LCD_RS=0; //RS=0 - Command. Mac dinh la ghi Command.
    if(rs)
        LCD_RS=1; //Kiem tra yeu cau ghi Data (rs=1) hay ghi Command (rs=0).
    //RS=1 - Data. Neu chon lua ghi Data.
    __delay_us(20);
    LCD_RW=0; //RW=0 - Write.
    __delay_us(20);
    LCD_EN=0; //EN=0 - Disable.
    temp.Val=b; //Lay gia tri thong tin can ghi vao LCD.
    LCD_DATA4=temp.bits.b4; //Gui 4 bit cao len bus.
    LCD_DATA5=temp.bits.b5;
    LCD_DATA6=temp.bits.b6;
    LCD_DATA7=temp.bits.b7;
    __delay_us(20);
    LCD_EN= 1; //EN=1 - Enable. Ghi 4 bit cao cua thong tin vao LCD.
    __delay_us(20);
    LCD_EN=0; //EN=0 - Disable.
    LCD_DATA4=temp.bits.b0; //Gui 4 bit thap len bus.
    LCD_DATA5=temp.bits.b1;
    LCD_DATA6=temp.bits.b2;
    LCD_DATA7=temp.bits.b3;
    __delay_us(20);
    LCD_EN=1; //EN=1 - Enable. Ghi 4 bit thap cua thong tin vao LCD.
    __delay_us(20);
    LCD_EN=0; //EN=0 - Disable.
}
void lcd_putc(char c)
{
    //Dinh nghia ham.
    switch(c)
    {
        case '\f': //Chuc nang xoa hien thi.
        {
            lcd_put_byte(0,0x01); //Goi ham truyen thong tin (lenh) sang C.LCD.
            while(lcd_busy()); //Kiem tra LCD bao ban.
            break; //Lenh: Xoa hien thi tren man hinh C.LCD (0x01).
        }
        case '\n': //Chuc nang bat dau hang thu 2.
        {
            lcd_gotoxy(0,1); //Goi ham truyen thong tin (du lieu) sang C.LCD.
            break;
        }
        case '\b': //Chuc nang lui ve 1 vi tri.
        {
            lcd_put_byte(0,0x10); //Goi ham truyen thong tin (lenh) sang C.LCD.
            while(lcd_busy()); //Kiem tra LCD bao ban.
            break; //Lenh: Doi con tro sang trai (0x10).
        }
        default: //Hien thi tat ca ky tu mac dinh trong LCD (c: dia chi HEX cua ky tu)
        {
            lcd_put_byte(1,c); //Gui thong tin sang LCD de hien thi tai toa do da xac dinh.
            while(lcd_busy()); //Kiem tra LCD bao ban.
            break;
        }
    }
}
void putch(char c)
{
    lcd_putc(c);
}
void lcd_gotoxy(unsigned char col,unsigned char row)
{
    //Khai bao bien.
    unsigned char address;
    //Dinh nghia ham.
    if(row!=0) //Kiem tra hang hien thi de tao dia chi hien thi hang.
        address=0x40; //Ma dieu khien hien thi hang 2.
    else
        address=0x00; //Ma dieu khien hien thi hang 1.
    address+=col; //Ket hop gia tri hang va cot de tao ra dia chi hien thi.
    lcd_put_byte(0,0x80|address); //Gui lenh xac dinh toa do hien thi tren LCD.
    while(lcd_busy()); //Kiem tra LCD bao ban.
}
void lcd_puts(const char *s)
{
    //Dinh nghia ham.
    while(*s)
        lcd_putc(*s++);
}