Atmega8 + termometr cyfrowy ds1820

Quote:

#include <mega8.h>

// 1 Wire Bus functions
#asm
.equ __w1_port=0x12 ;PORTD
.equ __w1_bit=3
#endasm
#include <1wire.h>
#include <ds1820.h>
#include <delay.h>
#include <stdio.h>

char lcd_buffer[33];
// DS1820 Temperature Sensor functions
#include <ds1820.h>

// maximum number of DS1820 devices
// connected to the 1 Wire bus
#define MAX_DS1820 8
// number of DS1820 devices
// connected to the 1 Wire bus
unsigned char ds1820_devices;
// DS1820 devices ROM code storage area,
// 9 bytes are used for each device
// (see the w1_search function description in the help)
unsigned char ds1820_rom_codes[MAX_DS1820,9];
unsigned char rom_code[MAX_DS1820,9];
// Alphanumeric LCD Module functions
#asm
.equ __lcd_port=0x12 ;PORTD
#endasm
#include <lcd.h>

// Declare your global variables here

void main(void)
{

unsigned char i,j,devices;
int temp;
// Declare your local variables here

// Input/Output Ports initialization
// Port B initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTB=0x00;
DDRB=0x00;

// Port C initialization
// Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTC=0x00;
DDRC=0x00;

// Port D initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTD=0x00;
DDRD=0x00;

// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: Timer 0 Stopped
TCCR0=0x00;
TCNT0=0x00;

// Timer/Counter 1 initialization
// Clock source: System Clock
// Clock value: Timer 1 Stopped
// Mode: Normal top=FFFFh
// OC1A output: Discon.
// OC1B output: Discon.
// Noise Canceler: Off
// Input Capture on Falling Edge
TCCR1A=0x00;
TCCR1B=0x00;
TCNT1H=0x00;
TCNT1L=0x00;
ICR1H=0x00;
ICR1L=0x00;
OCR1AH=0x00;
OCR1AL=0x00;
OCR1BH=0x00;
OCR1BL=0x00;

// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: Timer 2 Stopped
// Mode: Normal top=FFh
// OC2 output: Disconnected
ASSR=0x00;
TCCR2=0x00;
TCNT2=0x00;
OCR2=0x00;

// External Interrupt(s) initialization
// INT0: Off
// INT1: Off
MCUCR=0x00;

// Timer(s)/Counter(s) Interrupt(s) initialization
TIMSK=0x00;

// Analog Comparator initialization
// Analog Comparator: Off
// Analog Comparator Input Capture by Timer/Counter 1: Off
ACSR=0x80;
SFIOR=0x00;

// Determine the number of DS1820 devices
// connected to the 1 Wire bus
ds1820_devices=w1_search(0xf0,ds1820_rom_codes);

// LCD module initialization
lcd_init(16);
lcd_putsf("CodeVisionAVR\n1 Wire Bus Demo");
delay_ms(2000);
lcd_clear();
devices=w1_search(0xf0,rom_code);
sprintf(lcd_buffer,"%u DS1820\nDevice detected",devices);
lcd_puts(lcd_buffer);
delay_ms(2000);

if (devices)
{
for (i=0;i<devices;i++)
{
sprintf(lcd_buffer,"Device #%u ROM\nCode is:",i+1);
lcd_clear();
lcd_puts(lcd_buffer);
delay_ms(2000);
lcd_clear();
for (j=0;j<8;j++)
{
sprintf(lcd_buffer,"%02X ",rom_code[i][j]);
lcd_puts(lcd_buffer);
if (j==3) lcd_gotoxy(0,1);
};
delay_ms(5000);
};
}
else
while (1); /* stop here if no devices were found */

/* measure and display the temperature(s) */
while (1)
{
for (i=0;i<devices;)
{
temp=ds1820_temperature_10(&rom_code[i][0]);
j='+';
if (temp<0)
{
j='-';
temp=-temp;
};
sprintf(lcd_buffer,"t%u=%c%i.%u\xdfC",++i,j,temp/10,temp%10);
lcd_clear();
lcd_puts(lcd_buffer);
delay_ms(800);
};
};
}

Quote:

#ifndef _DS1820_INCLUDED_
#define _DS1820_INCLUDED_

#include <1wire.h>

#define DS1820_FAMILY_CODE 0x10
#define DS1820_SEARCH_ROM_CMD 0xf0
#define DS1820_ALARM_SEARCH_CMD 0xec

#pragma used+
extern struct __ds1820_scratch_pad_struct
{
unsigned char temp_lsb,temp_msb,
temp_high,temp_low,
res1,res2,
cnt_rem,cnt_c,
crc;
} __ds1820_scratch_pad;

unsigned char ds1820_select(unsigned char *addr);
unsigned char ds1820_read_spd(unsigned char *addr);
int ds1820_temperature_10(unsigned char *addr);
unsigned char ds1820_set_alarm(unsigned char *addr,signed char temp_low,signed char temp_high);
#pragma used-

#pragma library ds1820.lib

#endif

Quote:

Czym jest spowodowany fakt iż nie dostarczając napięcia do dsa " pracując w konfiguracji dwóch linii danych z podciągnięciem i masa " na pc czujnik działa ok a po podłączeniu do up nie można odczytać danych? Komunikacja jest poprawna ponieważ jest możliwe odczytanie id dsa.