原创 DS18B20的C程序

//     3.DS18B20数据口线的修改请参考DS18B20.h中的定义.

#include"DS18B20.h"
#include <IOM8v.h>
#include <macros.h>

void Delay1us(uchar value){
    value = value;
}
//---------------------------------------------
//name:Ds18b20Reset
//description:复位ds18b20芯片进行初始化
//parameter: no
//---------------------------------------------
void Ds18b20Reset(void){
    DS18B20_DQ_CLE;
    DelayUs(198);  //100us
    DelayUs(198); 
    DelayUs(198);
    DelayUs(198);
    DS18B20_DQ_SET;
    DelayUs(38);   //20us
}
//---------------------------------------------
//name:Ds18b20Ack
//description:应答单总线
//parameter: no
//---------------------------------------------
void Ds18b20Ack(void){
    while(DS18B20_DQ_DAT);
    while(!DS18B20_DQ_DAT);
    DelayUs(38);   //20us        
}
//---------------------------------------------
//name:Ds18b20Write
//description:   写一个字节
//parameter: dat 要写入的数据,无符号字符型
//---------------------------------------------

void Ds18b20Write(uchar data){
    uchar i;
    for(i=0;i<8;i++) {
        if(data & 0x01) {     // 写 1
            DS18B20_DQ_CLE;
            DelayUs(14);      //8us
            DS18B20_DQ_SET;
            DelayUs(108);     //55us 
        }else{                // 写 0
            DS18B20_DQ_CLE;
            DelayUs(108);     //55us
            DS18B20_DQ_SET;
            DelayUs(14);      //8us
        }
       data = data>>1;
    }
}
//---------------------------------------------
//name:Ds18b20ReadBit
//description:   读一个位
//parameter:     no
//---------------------------------------------
uchar Ds18b20ReadBit(void){
    uchar data;
    DS18B20_DQ_CLE;
    Delay1us(1);        //延时1个us
    DS18B20_DQ_SET;
    Delay1us(1);        //延时2个us
    Delay1us(1);
    data = DS18B20_DQ_DAT;
    DelayUs(118);      //60us
    return data;
}

//---------------------------------------------
//name:Ds18b20ReadByte
//description:   读一个字节
//parameter:     no
//---------------------------------------------
uchar Ds18b20ReadByte(void){
    uchar i,data;
    data = 0;
    for(i=0;i<8;i++){
        data = data >> 1;   
        if(Ds18b20ReadBit())
            data |= 0x80;
    }
    return data;
}
//---------------------------------------------
//name:Ds18b20Convert
//description:   命令Ds18b20开始转换温度
//parameter:     no
//---------------------------------------------
void Ds18b20Convert(void){
    Ds18b20Reset();
    Ds18b20Ack();
    delms(1);
    Ds18b20Write(DS18B20_SKIP_ROM);
    Ds18b20Write(DS18B20_CONVERT_TEM);
}
//---------------------------------------------
//name:Ds18b20ReadTem
//description:   从Ds18b20读取温度
//parameter:     no
//---------------------------------------------
uint Ds18b20ReadTem(void){
    uchar Height,Low;
    uint  Temp;
    Ds18b20Reset();                                   //初始化
    Ds18b20Ack();                                     
    delms(1);                                        
    Ds18b20Write(DS18B20_SKIP_ROM);                   //跳过ROM
    Ds18b20Write(DS18B20_READ_RAM);                   //读存储器
    Low    = Ds18b20ReadByte();
    Height = Ds18b20ReadByte();
    Temp   = (Height << 8) + Low;
    return Temp;
}