AT89S52语言常用程序——DS1820温度测量程序

#include <reg51.h>#include <absacc.h>#include <stdio.h>#include <math.h>#define uchar unsigned char#define uint unsigned intsbit P3_5=P3^5;uchar TEMP;// 温度值的变量；uchar flag1;// 结果为负和正的标志位。void delay (unsigned int count){unsigned int i;while (count){i =200;while (i>0) i--;count--;    }}void tmreset (void) // 发送复位和初始化{unsigned int i;P3_5 = 0;i = 103;while (i>0) i--;         // 延时P3_5 = 1;i = 4;while (i>0) i--;}bit tmpread (void)// 读取数据的一位{ unsigned int i;bit dat;P3_5 = 0; i++;P3_5 = 1; i++; i++;//延时dat = P3_5;i = 8; while (i>0) i--;// 延时return (dat);}unsigned char tmpread2 (void)  //读一个字节{unsigned char i,j,dat;dat = 0;for (i=1;i<=8;i++){j = tmpread ();dat = (j << 7) | (dat >> 1);}return (dat);}void tmpwrite (unsigned char dat)//写一个字节{   unsigned int i;unsigned char j;bit testb;for (j=1;j<=8;j++){testb = dat & 0x01;dat = dat >> 1;if (testb){P3_5 = 0; // 写0 i++; i++;  P3_5 = 1;i = 8; while (i>0) i--; }else{P3_5 = 0; // 写0 i = 8; while (i>0) i--; P3_5 = 1;i++; i++;  }}}void tmpchange(void)// ds1820 开始转换{  tmreset ();// 复位//tmpre ();// 等待存在脉冲delay (1);// 延时tmpwrite (0xcc);// 跳过序列号命令tmpwrite (0x44); // 发转换命令 44H,}void tmp (void)// 读取温度{ unsigned char a,b;tmreset ();// 复位delay (1);// 延时tmpwrite (0xcc); // 跳过序列号命令tmpwrite (0xbe); // 发送读取命令a = tmpread2 ();// 读取低位温度b = tmpread2 ();  //读取高位温度flag1=b;//若b为1则为负温if(flag1){TEMP=~a+1;//如果为负温则去除其补码}else{TEMP=a;}}rom()// 读取器件序列号子程序{tmreset ();//复位delay (1);//延时tmpwrite(0x33);//发送读序列号子程序}     main(){do{tmpchange();// 开始温度转换delay(200);// 读取延时tmp();//读取温度}while(1);}