notbadday
08-03-2009, 10:41 AM
Em đang viết 1 đoạn chương trình để hiển thị nhiệt độ lên LCD dùng cảm biến ds1820 và pic6f877a. Em đang gặp rắc rối trong việc giao tiếp với ds1820. Cụ thể là không hiện được nhiệt độ. Mấy anh xem giúp,có gì góp ý thì em cảm ơn rất nhiều.
Đây là code CCS, có mượn đoạn code phần LCD của bác nhh (hy vọng bác ko phản đối :) )
#include <16F877A.h>
#include <DEFS_16F877A.h>
#include <stdlib.h>
#fuses XT,NOWDT,NOPROTECT,NOLVP
#use delay(clock=4000000)
#define E RD2
#define RS RD0
#define RW RD1
#define DQ RC0
#DEFINE TRISC 0x07
#byte lcd_data = 0x06 // Dia chi PORTB
/* Khai bao nguyen mau cac ham su dung */
byte lcd_read_byte();
void lcd_send_byte( byte address, byte n );
void lcd_init();
void lcd_gotoxy( byte x, byte y);
void lcd_putc( char c);
void lcd_refresh();
unsigned char ow_reset(void);
unsigned char read_bit(void);
void write_bit(char bival);
unsigned char read_byte(void);
void write_byte(char val);
/* Doc mot byte tu LCD */
byte lcd_read_byte()
{
byte read_byte;
set_tris_B(0xFF); // PORTB = input
RW = 1;
delay_cycles(1);
E = 1;
delay_cycles(1);
read_byte = lcd_data;
E = 0;
set_tris_B(0x00); // PORTB = output
return(read_byte);
}
/* Goi 1byte den LCD */
void lcd_send_byte( byte address, byte n )
{
RS = 0;
while ( bit_test(lcd_read_byte(),7) ) ;
RS = address;
delay_cycles(1);
RW = 0;
delay_cycles(1);
E = 0;
lcd_data = n;
delay_cycles(1);
E = 1;
delay_us(2);
E = 0;
}
/* Khoi tao ban dau cho LCD */
void lcd_init()
{
byte const lcd_init_string[4] = {0x38, 0x0C, 1 , 6};
byte i;
set_tris_B(0x00);
RS = 0;
RW = 0;
E = 0;
delay_ms(15);
for(i=1;i<=3;++i)
{
lcd_data = 3;
delay_cycles(1);
E = 1;
delay_us(2);
E = 0;
delay_ms(5);
}
lcd_data = 2;
delay_cycles(1);
E = 1;
delay_us(2);
E = 0;
delay_ms(5);
for(i=0;i<=3;++i)
{
lcd_send_byte(0,lcd_init_string[i]);
}
}
/* Nhay den vi tri (x,y) tren LCD,nhay nham y se bao loi */
void lcd_gotoxy( byte x, byte y)
{
byte address;
switch(y)
{
case 1: address=0;
address+=x-1;
lcd_send_byte(0,0x80|address);
break;
case 2: address=0x40;
address+=x-1;
lcd_send_byte(0,0x80|address);
break;
default :lcd_init();
lcd_putc("ERROR Y POSITION");
while(true); // Dung tai day!
}
}
/* Hien thi ki tu hoac chuoi ra LCD */
void lcd_putc( char c)
{
lcd_send_byte(1,c);
}
/* Hien thi ki tu hoac chuoi ra LCD */
void lcd_refresh()
{
lcd_send_byte(0,1);
lcd_send_byte(0,6);
}
//reset
unsigned char ow_reset(void)
{
unsigned char presence;
set_tris_C(0);
DQ = 0; //pull DQ line low
delay_us(500); // leave it low for at least 480us
DQ = 1; // allow line to return high
delay_us(40); // wait for presence
set_tris_C(0x01);
presence = DQ; // get presence signal
delay_us(150); // wait for end of timeslot
return(presence); // presence signal returned
} // 0=presence, 1 = no part
unsigned char read_bit(void)
{
set_tris_C(0);
DQ = 0; // pull DQ low to start timeslot
delay_us(1);
set_tris_C(0x01); //release DQ
delay_us(15);
return(DQ); // return value of DQ line
}
void write_bit(char bitval)
{
set_tris_C(0);
DQ = 0; // pull DQ low to start timeslot
delay_us(15);
if(bitval==1) set_tris_C(0x01); //release DQ
delay_us(50); // hold value for remainder of timeslot
}
// READ_BYTE - reads a byte from the one-wire bus.
//
unsigned char read_byte(void)
{
unsigned char i;
unsigned char value = 0;
for (i=0;i<8;i++)
{
if(read_bit()) value|=0x01<<i; // reads byte in, one byte at a time and then
// shifts it left
delay_us(150); // wait for rest of timeslot
}
return(value);
}
void write_byte(char val)
{
unsigned char i;
unsigned char temp;
for (i=0; i<8; i++) // writes byte, one bit at a time
{
temp = val>>i; // shifts val right 'i' spaces
temp &= 0x01; // copy that bit to temp
write_bit(temp); // write bit in temp into
}
delay_us(100);
}
/* Ham main */
void main (void)
{
unsigned char x;
set_tris_B(0); //PORTB = output
set_tris_D(0); //PORTD = output
ow_reset();
write_byte(0xCC); // skip ROM
write_byte(0x44); // Start conversion
delay_us(100);
ow_reset();
write_byte(0xCC);
x = read_byte();
lcd_init();
lcd_gotoxy(5,1);
printf(lcd_putc,"temp = %u",x);
lcd_gotoxy(4,2);
lcd_putc("PICVIETNAM!");
}
Đây là code CCS, có mượn đoạn code phần LCD của bác nhh (hy vọng bác ko phản đối :) )
#include <16F877A.h>
#include <DEFS_16F877A.h>
#include <stdlib.h>
#fuses XT,NOWDT,NOPROTECT,NOLVP
#use delay(clock=4000000)
#define E RD2
#define RS RD0
#define RW RD1
#define DQ RC0
#DEFINE TRISC 0x07
#byte lcd_data = 0x06 // Dia chi PORTB
/* Khai bao nguyen mau cac ham su dung */
byte lcd_read_byte();
void lcd_send_byte( byte address, byte n );
void lcd_init();
void lcd_gotoxy( byte x, byte y);
void lcd_putc( char c);
void lcd_refresh();
unsigned char ow_reset(void);
unsigned char read_bit(void);
void write_bit(char bival);
unsigned char read_byte(void);
void write_byte(char val);
/* Doc mot byte tu LCD */
byte lcd_read_byte()
{
byte read_byte;
set_tris_B(0xFF); // PORTB = input
RW = 1;
delay_cycles(1);
E = 1;
delay_cycles(1);
read_byte = lcd_data;
E = 0;
set_tris_B(0x00); // PORTB = output
return(read_byte);
}
/* Goi 1byte den LCD */
void lcd_send_byte( byte address, byte n )
{
RS = 0;
while ( bit_test(lcd_read_byte(),7) ) ;
RS = address;
delay_cycles(1);
RW = 0;
delay_cycles(1);
E = 0;
lcd_data = n;
delay_cycles(1);
E = 1;
delay_us(2);
E = 0;
}
/* Khoi tao ban dau cho LCD */
void lcd_init()
{
byte const lcd_init_string[4] = {0x38, 0x0C, 1 , 6};
byte i;
set_tris_B(0x00);
RS = 0;
RW = 0;
E = 0;
delay_ms(15);
for(i=1;i<=3;++i)
{
lcd_data = 3;
delay_cycles(1);
E = 1;
delay_us(2);
E = 0;
delay_ms(5);
}
lcd_data = 2;
delay_cycles(1);
E = 1;
delay_us(2);
E = 0;
delay_ms(5);
for(i=0;i<=3;++i)
{
lcd_send_byte(0,lcd_init_string[i]);
}
}
/* Nhay den vi tri (x,y) tren LCD,nhay nham y se bao loi */
void lcd_gotoxy( byte x, byte y)
{
byte address;
switch(y)
{
case 1: address=0;
address+=x-1;
lcd_send_byte(0,0x80|address);
break;
case 2: address=0x40;
address+=x-1;
lcd_send_byte(0,0x80|address);
break;
default :lcd_init();
lcd_putc("ERROR Y POSITION");
while(true); // Dung tai day!
}
}
/* Hien thi ki tu hoac chuoi ra LCD */
void lcd_putc( char c)
{
lcd_send_byte(1,c);
}
/* Hien thi ki tu hoac chuoi ra LCD */
void lcd_refresh()
{
lcd_send_byte(0,1);
lcd_send_byte(0,6);
}
//reset
unsigned char ow_reset(void)
{
unsigned char presence;
set_tris_C(0);
DQ = 0; //pull DQ line low
delay_us(500); // leave it low for at least 480us
DQ = 1; // allow line to return high
delay_us(40); // wait for presence
set_tris_C(0x01);
presence = DQ; // get presence signal
delay_us(150); // wait for end of timeslot
return(presence); // presence signal returned
} // 0=presence, 1 = no part
unsigned char read_bit(void)
{
set_tris_C(0);
DQ = 0; // pull DQ low to start timeslot
delay_us(1);
set_tris_C(0x01); //release DQ
delay_us(15);
return(DQ); // return value of DQ line
}
void write_bit(char bitval)
{
set_tris_C(0);
DQ = 0; // pull DQ low to start timeslot
delay_us(15);
if(bitval==1) set_tris_C(0x01); //release DQ
delay_us(50); // hold value for remainder of timeslot
}
// READ_BYTE - reads a byte from the one-wire bus.
//
unsigned char read_byte(void)
{
unsigned char i;
unsigned char value = 0;
for (i=0;i<8;i++)
{
if(read_bit()) value|=0x01<<i; // reads byte in, one byte at a time and then
// shifts it left
delay_us(150); // wait for rest of timeslot
}
return(value);
}
void write_byte(char val)
{
unsigned char i;
unsigned char temp;
for (i=0; i<8; i++) // writes byte, one bit at a time
{
temp = val>>i; // shifts val right 'i' spaces
temp &= 0x01; // copy that bit to temp
write_bit(temp); // write bit in temp into
}
delay_us(100);
}
/* Ham main */
void main (void)
{
unsigned char x;
set_tris_B(0); //PORTB = output
set_tris_D(0); //PORTD = output
ow_reset();
write_byte(0xCC); // skip ROM
write_byte(0x44); // Start conversion
delay_us(100);
ow_reset();
write_byte(0xCC);
x = read_byte();
lcd_init();
lcd_gotoxy(5,1);
printf(lcd_putc,"temp = %u",x);
lcd_gotoxy(4,2);
lcd_putc("PICVIETNAM!");
}