[nhanthienthan]

Chương trình viết chữ XIN CHAO đơn giản như thế này

#include <16f877A.h>
#fuses HS, NOLVP, NOWDT, NOPROTECT
#use   delay (clock=4000000) //Use built-in function: delay_ms() & delay_us()
#include "LCD_LIB_4BIT.c" 


VOID MAIN()

{
   LCD_INIT();
   LCD_PUTCHAR('X');
   DELAY_MS(1000);
   LCD_PUTCHAR('I');
   DELAY_MS(1000);
   LCD_PUTCHAR('N');
   DELAY_MS(1000);
   LCD_PUTCHAR(' ');
   DELAY_MS(1000);
   LCD_PUTCHAR('C');
   DELAY_MS(1000);
   LCD_PUTCHAR('H');
   DELAY_MS(1000);
   LCD_PUTCHAR('A');
   DELAY_MS(1000);
   LCD_PUTCHAR('O');
}

Còn đây là file LCD_LIB_4BIT.c

#include <stddef.h>
#define LCD_RS          PIN_B2
#define LCD_EN          PIN_B3
#define LCD_D4          PIN_B4
#define LCD_D5          PIN_B5
#define LCD_D6          PIN_B6
#define LCD_D7          PIN_B7
#define Line_1          0x80
#define Line_2          0xC0
#define Clear_Scr       0x01
#separate void LCD_Init ();// ham khoi tao LCD
#separate void LCD_SetPosition ( unsigned int cX );//Thiet lap vi tri con tro
#separate void LCD_PutChar ( unsigned int cX );// Ham viet1kitu/1chuoi len LCD
#separate void LCD_PutCmd ( unsigned int cX) ;// Ham gui lenh len LCD
#separate void LCD_PulseEnable ( void );// Xung kich hoat
#separate void LCD_SetData ( unsigned int cX );// Dat du lieu len chan Data

//khoi tao LCD**********************************************
#separate void LCD_Init ()
    {
    LCD_SetData ( 0x00 );
    delay_ms(20);       /*Cho cho lcd khoi tao */
    output_low ( LCD_RS );// che do gui lenh
    LCD_SetData ( 0x03 );   /* khoi tao che do 4 bit */
    LCD_PulseEnable();
    LCD_PulseEnable();
    LCD_PulseEnable();
    LCD_SetData ( 0x02 );   /* tao giao dien 4 bit */
    LCD_PulseEnable();      /* send dual nibbles hereafter, MSN first */
    LCD_PutCmd ( 0x2C );    /* function set (all lines, 5x7 characters) */
    LCD_PutCmd ( 0x0C );    /* display ON, cursor off, no blink */
    LCD_PutCmd ( 0x06 );    /* entry mode set, increment & scroll left */
    LCD_PutCmd ( 0x01 );    /* clear display */

    // Init for BarGraph

    }

#separate void LCD_SetPosition ( unsigned int cX )
    {
    /* this subroutine works specifically for 4-bit Port A */
    LCD_SetData ( swap ( cX ) | 0x08 );
    LCD_PulseEnable();
    LCD_SetData ( swap ( cX ) );
    LCD_PulseEnable();
    }

#separate void LCD_PutChar ( unsigned int cX )
    {
    /* this subroutine works specifically for 4-bit Port A */
        output_high ( LCD_RS );
        LCD_PutCmd( cX );
        output_low ( LCD_RS );
    }
#separate void LCD_PutCmd ( unsigned int cX )
    {
    LCD_SetData ( swap ( cX ) );     /* send high nibble */
    LCD_PulseEnable();
    LCD_SetData ( swap ( cX ) );     /* send low nibble */
    LCD_PulseEnable();
    }
#separate void LCD_PulseEnable ( void )
    {
    output_high ( LCD_EN );
    delay_us ( 3 );         // was 10
    output_low ( LCD_EN );
    delay_ms ( 3 );         // was 5
    }
#separate void LCD_SetData ( unsigned int CX )
    {
    output_bit ( LCD_D4, CX & 0x01 );
    output_bit ( LCD_D5, CX & 0x02 );
    output_bit ( LCD_D6, CX & 0x04 );
    output_bit ( LCD_D7, CX & 0x08 );
    }

Viết trong CCS nhưng khi em nhấn f9 thì nó hiện lỗi này là sao ạ

***Eroor 128"LCD_LIB_4BIT.c"Line12(2,10): A#DEVICE require before this line

Mong các bro giúp đỡ, em mới học Pic nên chưa thành thạo lăm