CT107D DS18B20
先贴上核心代码
unsigned char get_temp(void)
{
unsigned char TH,TL;
init_ds18b20();
Write_DS18B20(0xCC);
Write_DS18B20(0x44);
Delay_OneWire(200);
init_ds18b20();
Write_DS18B20(0xCC);
Write_DS18B20(0xBE);
TL=Read_DS18B20();
TH=Read_DS18B20();
return (TH<<4)|(TL>>4);
}先创建了两个变量用于储存获取到的温度，再使用官方自带的onewire库初始化DS18B20
Write_DS18B20(0xCC); Write_DS18B20(0x44);
写入了两个值，这个值是什么意思呢？
0xCC代表跳过ROM
0x44代表转换命令
在延时之后，我们重新初始化了DS18B20，然后写入了
Write_DS18B20(0xCC); Write_DS18B20(0xBE);
0xCC代表跳过ROM上面说过了，0xBE代表读取温度，准确的说，是读取寄存器，但是上面告知了芯片进行温度转换，这里读取得到的就是温度了。
#include<reg52.h>
#include<intrins.h>
#include<onewire.h>
/*部分代码来源于STC*/
//本示例在Keil开发环境下请选择Intel的8058芯片型号进行编译
//若无特别说明,工作频率一般为11.0592MHz
#include "intrins.h"
typedef unsigned char BYTE;
typedef unsigned int WORD;
#define FOSC 11059200L //系统频率
#define BAUD 115200 //串口波特率
#define NONE_PARITY 0 //无校验
#define ODD_PARITY 1 //奇校验
#define EVEN_PARITY 2 //偶校验
#define MARK_PARITY 3 //标记校验
#define SPACE_PARITY 4 //空白校验
#define PARITYBIT NONE_PARITY //定义校验位
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P1M1 = 0x91;
sfr P1M0 = 0x92;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xb1;
sfr P3M0 = 0xb2;
sfr P4M1 = 0xb3;
sfr P4M0 = 0xb4;
sfr P5M1 = 0xC9;
sfr P5M0 = 0xCA;
sfr P6M1 = 0xCB;
sfr P6M0 = 0xCC;
sfr P7M1 = 0xE1;
sfr P7M0 = 0xE2;
sfr AUXR = 0x8e; //辅助寄存器
sfr P_SW1 = 0xA2; //外设功能切换寄存器1
#define S1_S0 0x40 //P_SW1.6
#define S1_S1 0x80 //P_SW1.7
sbit P22 = P2^2;
bit busy;
void SendData(BYTE dat);
void SendString(char *s);
void init_hwd()
{
P2=0xA0;
P0=0x00;
P2=0x00;
P0=0x80;
P0=0xFF;
P0=0x00;
P2=0x00;
}
void main()
{
init_hwd();
P0M0 = 0x00;
P0M1 = 0x00;
P1M0 = 0x00;
P1M1 = 0x00;
P2M0 = 0x00;
P2M1 = 0x00;
P3M0 = 0x00;
P3M1 = 0x00;
P4M0 = 0x00;
P4M1 = 0x00;
P5M0 = 0x00;
P5M1 = 0x00;
P6M0 = 0x00;
P6M1 = 0x00;
P7M0 = 0x00;
P7M1 = 0x00;
ACC = P_SW1;
ACC &= ~(S1_S0 | S1_S1); //S1_S0=0 S1_S1=0
P_SW1 = ACC; //(P3.0/RxD, P3.1/TxD)
// ACC = P_SW1;
// ACC &= ~(S1_S0 | S1_S1); //S1_S0=1 S1_S1=0
// ACC |= S1_S0; //(P3.6/RxD_2, P3.7/TxD_2)
// P_SW1 = ACC;
//
// ACC = P_SW1;
// ACC &= ~(S1_S0 | S1_S1); //S1_S0=0 S1_S1=1
// ACC |= S1_S1; //(P1.6/RxD_3, P1.7/TxD_3)
// P_SW1 = ACC;
#if (PARITYBIT == NONE_PARITY)
SCON = 0x50; //8位可变波特率
#elif (PARITYBIT == ODD_PARITY) || (PARITYBIT == EVEN_PARITY) || (PARITYBIT == MARK_PARITY)
SCON = 0xda; //9位可变波特率,校验位初始为1
#elif (PARITYBIT == SPACE_PARITY)
SCON = 0xd2; //9位可变波特率,校验位初始为0
#endif
AUXR = 0x40; //定时器1为1T模式
TMOD = 0x00; //定时器1为模式0(16位自动重载)
TL1 = (65536 - (FOSC/4/BAUD)); //设置波特率重装值
TH1 = (65536 - (FOSC/4/BAUD))>>8;
TR1 = 1; //定时器1开始启动
ES = 1; //使能串口中断
EA = 1;
//SendString("STC15F2K60S2\r\nUart Test !\r\n");
while(1)
{
SendData(rd_temperature());
}
}
/*----------------------------
UART 中断服务程序
-----------------------------*/
void Uart() interrupt 4
{
if (RI)
{
RI = 0; //清除RI位
P0 = SBUF; //P0显示串口数据
P22 = RB8; //P2.2显示校验位
}
if (TI)
{
TI = 0; //清除TI位
busy = 0; //清忙标志
}
}
/*----------------------------
发送串口数据
----------------------------*/
void SendData(BYTE dat)
{
while (busy); //等待前面的数据发送完成
ACC = dat; //获取校验位P (PSW.0)
if (P) //根据P来设置校验位
{
#if (PARITYBIT == ODD_PARITY)
TB8 = 0; //设置校验位为0
#elif (PARITYBIT == EVEN_PARITY)
TB8 = 1; //设置校验位为1
#endif
}
else
{
#if (PARITYBIT == ODD_PARITY)
TB8 = 1; //设置校验位为1
#elif (PARITYBIT == EVEN_PARITY)
TB8 = 0; //设置校验位为0
#endif
}
busy = 1;
SBUF = ACC; //写数据到UART数据寄存器
}
/*----------------------------
发送字符串
----------------------------*/
void SendString(char *s)
{
while (*s) //检测字符串结束标志
{
SendData(*s++); //发送当前字符
}
}值得一提的是，官方给的延时函数是错误的，会导致DS18B20 输出的结果一直是0xFF，需要延长时间
//单总线延时函数
void Delay_OneWire(unsigned int t)
{
char z;
while(t--)
for(z=0;z<12;z++);
}
