基于DS18B20的数字温度计设计.zip_51单片机_C语言_proteus

#include<reg52.h> #define SMG P2 sbit ds = P1^6; sbit SMG_1 = P1^0; sbit SMG_2 = P1^1; sbit SMG_3 = P1^2; sbit SMG_4 = P1^3; unsigned char flag; //判断温度值正负 unsigned char code table1[] = {0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xbf}; //共阳数码管 无小数点 unsigned char code table2[] = {0x40,0x79,0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10}; //共阳数码管 有小数点 void delay(unsigned char time) { unsigned char i,j; for(i=0;i<time;i++) for(j=0;j<110;j++); } void dsreset() //DS18B20初始化 { unsigned int i; ds = 1; i = 8; while(i>0)i--; ds = 0; i = 80; while(i>0)i--; ds = 1; i = 14; while(i>0)i--; } bit tempreadbit() //读一位二进制码 { unsigned int i; bit dat; ds = 0; i++; ds = 1; i++; i++; dat = ds; i = 4; while(i>0) i--; return dat; } unsigned char tempread() { unsigned char i,j,dat; dat = 0; for(i=0;i<8;i++) { j = tempreadbit(); dat = (j<<7)|(dat>>1); //读出的数据最低位排在前面 } return dat; } void tempwritebyte(unsigned char dat) //写一个字节数据 { unsigned int i; unsigned char j; bit testb; for(j=0;j<8;j++) { testb = dat&0x01; dat = dat>>1; if(testb) //写1 { ds = 0; i++;i++; ds = 1; i = 8; while(i>0) i--; } else //写0 { ds = 0; i = 8; while(i>0)i--; ds = 1; i++; i++; } } } void tempchange() //获取温度并转换 { dsreset(); delay(1); tempwritebyte(0xcc); //写跳过读ROM指令 tempwritebyte(0x44); //写温度转换指令 } unsigned int get_temp() //读取寄存器中存储的温度 { unsigned char a,b; unsigned int temp; float f_temp; dsreset(); delay(1); tempwritebyte(0xcc); //写跳过读ROM指令 tempwritebyte(0xbe); //读取暂存器的温度 a = tempread(); //读低八位 b = tempread(); //读高八位 temp = b; temp <<= 8; //两个字节组合为1个字 temp = temp|a; if(temp>0xf800) //判断是否为负温度 { flag = 1; temp = ~temp + 1; } else { flag = 0; } f_temp = temp*0.0625; //温度在寄存器中为12位，分辨率为0.0625° temp = f_temp*10+0.5; return temp; } void display(unsigned int num) { unsigned char i,j,k,z; i = num/1000; j = num/100%10; k = num%100/10; z = num%10; SMG_1 = 0; SMG_2 = 0; SMG_3 = 0; SMG_4 = 0; if(i>0) { SMG_4 = 1; SMG = table1[i]; delay(10); SMG_4 = 0; SMG_3 = 1; SMG = table1[j]; delay(10); SMG_3 = 0; SMG_2 = 1; SMG = table2[k]; delay(10); SMG_2 = 0; SMG_1 = 1; SMG = table1[z]; delay(10); SMG_1 = 0; } else if(j>0) { SMG_4 = 0; SMG_3 = 1; SMG = table1[j]; delay(10); SMG_3 = 0; SMG_2 = 1; SMG = table2[k]; delay(10); SMG_2 = 0; SMG_1 = 1; SMG = table1[z]; delay(10); SMG_1 = 0; } else { SMG_4 = 0; SMG_3 = 0; SMG_2 = 1; SMG = table2[k]; delay(10); SMG_2 = 0; SMG_1 = 1; SMG = table1[z]; delay(10); SMG_1 = 0; } if(flag == 1) { if(j>0) { SMG_4 = 1; SMG = table1[10]; //显示负号 delay(10); SMG_4 = 0; } else { SMG_3 = 1; SMG = table1[10]; //显示负号 delay(10); SMG_3 = 0; } } } void main() { while(1) { tempchange(); display(get_temp()); } }