ALPS-004/WZYXPCR_NO1.20250726.X/WZYXPCR_NO1.20250726.X/file/DS1802.c

#include "DS1802.h"
#include "ABIS_User.h"

//us级别延时函数1~20精度高20us，偏差1us
void DelayUs(unsigned int Tmr)
{
	unsigned char i;
	for(i=0;i<2;i++){
		asm("nop");
		asm("nop");
		asm("nop");
	}
	if(Tmr > 1){
		Tmr -= 1;
		for(;Tmr>0;Tmr--){
			for(i=0;i<3;i++){
                asm("nop");
                asm("nop");
                asm("nop");
			}
            asm("nop");
		}
	}
}

void Ds18WriteChar(unsigned char data)  //向Ds18b20写函数
{
    unsigned char i,temp;
	DQ_HIGH();
    DelayUs(3); 
	for(i=8;i>0;i--){
		temp = data&0x01;  
		DQ_LOW();
		DelayUs(20);
		if(temp == 1)DQ_HIGH();
		DelayUs(45);
		DQ_HIGH();
		data=data>>1;
	}
}
unsigned char Ds18ReadChar()
{
	unsigned char i,data=0;	
	for(i=8;i>0;i--){
		data=data>>1;
		DQ_HIGH();
	    DelayUs(3);
		DQ_LOW();
		DelayUs(6);
		DQ_HIGH();
		DelayUs(4);
		if(DQ)data=data|0x80;
		DelayUs(30);
	}
	return (data);
}
void Ds18Start()
{
	unsigned char i=10;
	DQ_HIGH();
	DelayUs(3); 
	while(i){
        DQ_LOW();
        DelayUs(750); //延时750us
        DQ_HIGH();
        DelayUs(70); //延时70us
        if (DQ == 1)i--;
        else i = 0;
        DelayUs(500); //延时500us
	}
}
void Ds18Init()
{
	Ds18Start();
	Ds18WriteChar(0xcc);
	Ds18WriteChar(0x4e);
	Ds18WriteChar(0x64);
	Ds18WriteChar(0x8a);
}
float DS18GetTemp()
{
	unsigned char tl,th;
	float temp;
    
	Ds18Start();
	Ds18WriteChar(0xcc);
	Ds18WriteChar(0x44);
	Delay_ms(750);                          //暂时屏蔽
	Ds18Start();
	Ds18WriteChar(0xcc);
	Ds18WriteChar(0xbe);
	tl=Ds18ReadChar();
	th=Ds18ReadChar();
	Ds18Start();
    
    temp = th;
    temp*= 256;
    temp+= tl;
    temp*= 0.0625;
	return(temp);
}