ds18b20.c

P89C61X2上的18b20程序

#define  DS18B20_GLOBALS
#include <reg52.h>
#include <DS18B20.h>

void Delay20uS(uchar dly)
{
	uchar i;
	for(;dly>0;dly--)
		{
		for(i=0;i<18;i++);
		}
}
void Delay15uS(uchar dly)
{
	uchar i;
	for(;dly>0;dly--)
		{
		for(i=0;i<15;i++);
		}
}
void RST_18B20(void)
{
	DIO_Temp = 1;
	DIO_Temp = 0;
	Delay20uS(30);		//about 600us
	DIO_Temp = 1;
	Delay20uS(2);		//about 40us
	DIO_Temp = 0;
	Delay20uS(5);		//about 100us
	DIO_Temp = 1;
	Delay20uS(30);		//about 600us
}
void Write_Byet(uchar Byte)
{
	uchar i;
	for(i=0;i<8;i++)
	{
	DIO_Temp = 0;
	Delay15uS(1);		//about 15us
	DIO_Temp = (Byte & 0x01);
	Delay20uS(3);		//about 60us
	DIO_Temp = 1;
	Byte = (Byte/2);
	}
}
uchar Read_Byte(void)
{
	uchar i,rev_data;
	for(i=0;i<8;i++)
	{
	DIO_Temp = 0;
	Delay15uS(1);		//about 15us
	DIO_Temp = 1;
	rev_data = (rev_data >> 1);
	if(DIO_Temp)
		rev_data = (rev_data | 0x80);
	else ;
	Delay20uS(3);		//about 60us
	}
	return rev_data;
}
void Get_Temp(void)
{
	RST_18B20();
	Write_Byet(0xCC);
	Write_Byet(0x44);
	RST_18B20();
	Write_Byet(0xCC);
	Write_Byet(0xBE);
	Temp_Data_dec = Read_Byte();
	Temp_Data_int = Read_Byte();
	Temp_Data_int = ((Temp_Data_int<<4)|(Temp_Data_dec>>4));
	Temp_Data_dec = (Temp_Data_dec & 0x0F);
}
/*
void main(void)
{
	uint i;
	for(i=0;i<3000;i++)
		Delay20uS(50);	
	for(i=0;i<50;i++)
			REC_Buff[i] = '\0';
	REC_Count = 0;
	UART_Init();
	EA=1;               // 开中断
	ES=1;               //允许串口接收中断
	Send_Char('U');
	for(i=0;i<300;i++)
		Delay20uS(50);	
	Send_Char('U');
	for(i=0;i<300;i++)
		Delay20uS(50);	
	Send_Char('U');
	for(i=0;i<300;i++)
		Delay20uS(50);	
	Send_Char('U');
	DIO_Temp = 1;
	Delay20uS(200);	
	while(1)
	{
	Get_Temp();
	Send_Char(Temp_Data_int);
	Send_Char(Temp_Data_dec);
	for(i=0;i<3000;i++)
		Delay20uS(50);	
	}
}
*/