main_18b20.c

F:程序DS18B20.rar索读取温度

//ICC-AVR application builder : 2008-4-7 PM 04:31:51
// Target : M16
// Crystal: 8.0000Mhz

#include <iom16v.h>
#include <macros.h>
#include "DS18B20.h"

void port_init(void)
{
 PORTA = 0x00;
 DDRA  = 0x00;
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0xFF;
 PORTD = 0x00;
 DDRD  = 0x00;
}

//TIMER0 initialize - prescale:1024
// WGM: Normal
// desired value: 25mSec
// actual value: 24.960mSec (0.2%)
void timer0_init(void)
{
 TCCR0 = 0x00; //stop
 TCNT0 = 0x3D; //set count
 OCR0  = 0xC3;  //set compare
 TCCR0 = 0x05; //start timer
}

#pragma interrupt_handler timer0_ovf_isr:iv_TIM0_OVF
void timer0_ovf_isr(void)
{
 TCNT0 = 0x3D; //reload counter value
}

//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
void uart0_init(void)
{
 UCSRB = 0x00; //disable while setting baud rate
 UCSRA = 0x00;
 UCSRC = BIT(URSEL) | 0x06;
 UBRRL = 0x33; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0x98;
}

#pragma interrupt_handler uart0_rx_isr:iv_USART0_RXC
void uart0_rx_isr(void)
{
 //uart has received a character in UDR
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 timer0_init();
 uart0_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x01; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

 //输出一个字符
void putchar(unsigned char TmpCh)
{	
	while( !(UCSRA & (1<<UDRE)) );
	UDR = TmpCh;	
}

void main(void)
{
  unsigned char tempout = 0;
  init_devices();
  init_1820();
  putchar(0xFF);
  delay_nms(200);
  ;
  while(1)
     {
	  tempout = gettemp();
	  delay_nms(30);
	  putchar(tempout);
	  //putchar(wml);
	  delay_nms(3000); 
	 };
};