giao tiep PIC16F877-DS1620......?

[andyhug]

Đề tài này có vẻ ít người làm nhẩy!..
Cuối cùng thì cũng đọc được nhiệt độ, mọi người ai biết giúp tôi thiết đặt giới hạn nhiệt độ cao, thấp với(write TH, TL)!
Đây là phần code:

xxxxxxxxxxxxxxxxx Interface PIC6F877-DS1620xxxxxxxxxxxxxxxxxxx
//*-----------------------------------------------------------------------------
//* Tac gia       		: Pham Thanh Cong
//* Ngay viet     		: 18/06/2008
//* Ngay hoan thanh	: 22/07/2008
//* Phan cung     		: PIC16F877, LCD 2x16[5x7], DS1620
//* Chuong trinh  		: do nhiet do dung DS1620 hien thi tren LCD LMB162A
//*===========================================================================*/
// Khoi tien xu ly
#include <16F877A.h>
#include <stdlib.h>
#include <string.h>
#fuses XT,NOWDT,NOPROTECT,NOLVP  // dat cau hinh cho PIC
#use delay(clock=4000000)
#use fast_io(A)                  // su dung cung voi lenh set_tris
#use fast_io(B)
#use fast_io(D)
#byte   PORTB    = 0x06
#define LCD PORTB
#bit RA2         = 0x05.2
#bit RA1         = 0x05.1
#bit RA0         = 0x05.0
#define RS  RA0               // chan chon thanh ghi =0 lenh hay =1 du lieu
#define RW  RA1               // =1 doc hay =0 ghi
#define E   RA2               // H-to-L de cho fep LCD
#bit RD1         = 0x08.1     // chan data cua DS1620
#bit RD2         = 0x08.2     // chan dong ho
#bit RD3         = 0x08.3     //
#define DQ     RD1            // =0 output, =1 input
#define CLK    RD2
#define RST    RD3
// khai bao cac ham su dung trong chuong trinh
void LCD_init(void);
void comandwrt(void);
void datawrt(void);
void LCD_gotoxy(byte x, byte y);
void DS1620_InitTemp(void);
unsigned int8 DS1620_GetTemp(void);
void DS1620_Write(unsigned char Data);
unsigned int8 DS1620_Read(void);
void display(int8 temp);
void main(void);
// Cac bien toan cuc
const unsigned char dongchu[]="Nhiet do:";      // Hang so toan cuc
int i = 0, sign = 0;                                      // Bien toan cuc
//xxxxxxxxxxxxxxxxxxxxxxxxxxx CHUONG TRINH LCD xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
// Khoi tao cho LCD
void LCD_init()
{
   delay_ms(50);       // tre it nhat 30ms
   LCD = 0x38;         // Hai hang, ma tran diem 5*8, 8 bit interface
   comandwrt();    
   delay_us(50);       // tre it nhat 39us
   LCD = 0x0C;         // bat hien thi, tat con tro va tat nhap nhay
   comandwrt();    
   delay_us(50);       // tre it nhat 39us
   LCD = 0x01;         // xoa man hinh
   comandwrt();    
   delay_ms(3);        // tre it nhat 1.53ms
   LCD = 0x06;         // che do tang con tro sau khi viet 1 ki tu
   comandwrt();        // va chu khong chay
   delay_ms(1);
}
// Ham gui lenh ra LCD
void comandwrt(void)
{
 RS = 0;
 RW = 0;
 E  = 1;
 E  = 0;
 delay_ms(1);
}
// Ham gui du lieu ra LCD
void datawrt(void)
{
 RS = 1;
 RW = 0;
 E  = 1;
 E  = 0;
 delay_ms(1);
}
// Ham di chuyen con tro toi vi tri xy(cot,hang) tren man hinh LCD
void LCD_gotoxy(int x, int y)
{  int address;
   switch(y)
      {
         case 1:  address=0;
                  address+=x-1;
                  LCD = (0x80 + address);    // dong 1, cot1: 80h
                  break;
         case 2:  address=0;
                  address+=x-1;
                  LCD = (0xC0 + address);    // dong 2, cot1: C0h
                  break;
         default : break; 
      }
}
//xxxxxxxxxxxxxxxxxxxxxxxxxxx CHUONG TRINH DS1620 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
// Khoi tao DS1620
void DS1620_InitTemp(void)
{
      RST = 1;               // thiet lap che do giao tiep 3-wire .
      DS1620_Write(0x0C);    // cho phep ghi config 
      DS1620_Write(0x00);// xoa thanh ghi config, thiet lap chuyen doi lien tuc
      RST = 0;
      RST = 1;               // thiet lap che do giao tiep 3-wire
      DS1620_Write(0xEE);    // bat dau chuyen doi nhiet do
      RST =0;
} 

void DS1620_Write(unsigned char Data)
{
   unsigned char i;
   set_tris_D(0);           // cong D la cong ra
   CLK = 1;                 // tao clock
   for (i=1; i<=8; ++i)
      {
       DQ = (Data & 1);    // viet bit thap len DQ
       CLK = 0;
       CLK = 1;            // tao clock
       Data = Data >> 1;   // dich dl
      }
}

unsigned int8 DS1620_Read(void)
{
   unsigned int8 Data, temp;
   set_tris_D(0x02);       // Chan DQ = 1 : chan vao, con lai la chan ra
   Data = 0;
   temp = 1;
   CLK = 1;
   for (i=1; i<=8; ++i)
   {
       CLK = 0;                    // CLK = 0: convert 
       if (DQ == 1) Data += Temp; //neu DQ = 1, cong don Data
       Temp = Temp << 1;        // neu DQ = 0, dich trai temp 1bit de chen 0 vao
       CLK = 1;
   }
   CLK = 0;
   if (DQ == 1) Sign = 1;// Lay gia tri bit dau, bit thu 9
   else Sign = 0;
   CLK = 1;
   return(Data);
}

unsigned int8 DS1620_GetTemp(void)
{
   unsigned int8 Data;
   RST =1;                  // thiet lap che do giao tiep 3-wire
   DS1620_Write(0xAA);      // lenh cho phep doc noi dung thanh ghi nhiet
   data = DS1620_Read();    // doc noi dung
   RST =0;                  // ket thuc che do giao tiep 3-wire
   return(data);           
} 

void display(int8 temp)
{
   int8 Data, leng;
   unsigned char string[3];
   if (sign == 1)
   {
      LCD_gotoxy(5,2);
      comandwrt();
      LCD = '-';
      datawrt();
      Data = ~(temp - 1) / 2;
      
   }
   else  {  LCD_gotoxy(5,2);
            comandwrt();
            LCD = '+';
            datawrt();
            Data = temp / 2;
         }
   itoa(Data,10,string);
   leng = strlen(string);
   if (bit_test(temp,0)) 
   {
      for(i=0;i<leng;i++)
      {
         LCD = string[i]; // xuat nhiet do ra o dang ki tu so
         datawrt();
      }
      LCD = '.'; 
      datawrt();
      LCD = '5';
      datawrt();
      LCD = ' ';
      datawrt();
      LCD = 'd';
      datawrt();
      LCD = 'o';
      datawrt();
      LCD = 'C';
      datawrt();
   }
   else
   {
      for(i=0;i<leng;i++)
      {
         LCD = string[i]; // 
         datawrt();
      }
      LCD = '.'; 
      datawrt();
      LCD = '0';
      datawrt();
      LCD = ' ';
      datawrt();
      LCD = 'd';
      datawrt();
      LCD = 'o';
      datawrt();
      LCD = 'C';
      datawrt();
   }
}

//xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Ham main xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
void main(void)
{
   int8 data;
   set_tris_B(0);                   // cong ra
   set_tris_A(0);                   // cong ra
   LCD_init();                      // dat che do hoat dong cho LCD
   delay_us(2);
   DS1620_InitTemp();
   delay_ms(2);
   LCD_gotoxy(5,1);                 // Vi tri cot 5, hang 1
   comandwrt();
   for (i=0;i<=8;i++)
   {
      LCD = dongchu[i];             // xuat chu ra LCD
      datawrt();
      
   }
   while(1)
   {
      data  = DS1620_GetTemp();     // lay du lieu
      display(data);
   }
}