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最常用的溫度傳感器 上至128° 下至-55°
//數(shù)字式溫度計(jì)
#include <reg51.h>
#include <intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit LED = P3^0; //滅掉一顆LED
int temp;
int wendu;
uchar data disdata[5];
//定義開關(guān)入口
sbit DQ = P1^7;//DS18B20的接入口
sbit lcden=P2^1;
sbit lcdrs=P2^0;
sbit LED1=P3^0;
sbit LED2=P3^7;
//聲明區(qū)
void write_com(uchar com);
void delay(uint);
//定義區(qū)
void delay(uint i)
{
while(i--);
}
void delay_1(int z)
{
int x,y;
for(x=0;x<z;x++)
for(y=0;y<122;y++);
}
//液晶函數(shù)
void init()
{
lcden=0;
write_com(0x38);//設(shè)置顯示模式為5*7八位數(shù)據(jù)接口
write_com(0x0c); //開顯示，顯示光標(biāo)光標(biāo)不閃爍
write_com(0x06); //光標(biāo)指針自動(dòng)加1
write_com(0x01);//清屏
write_com(0x80+2);//顯示數(shù)據(jù)的地址
}
void write_com(uchar com)
{
lcdrs=0;
P0=com;
delay_1(10);
lcden=1;
delay_1(10);
lcden=0;
}
void write_data(uchar date)
{
lcdrs=1;
P0=date;
delay_1(10);
lcden=1;
delay_1(10);
lcden=0;
}
//以上為液晶要用到的函數(shù)
//ds18b20溫度傳感器所需函數(shù)，分為初始化 讀字節(jié) 寫字節(jié) 讀取溫度4個(gè)函數(shù)
void Init_DS18B20() //初始化
{
uchar x=0;
DQ=1;
_nop_();
_nop_();
DQ=0;
delay(70);
DQ=1;
delay(15);
x=DQ;
delay(35);
}
uchar Read_OneChar() //讀一個(gè)字節(jié)
{
uchar i;
uchar temp=0;
for(i=0;i<8;i++)
{
DQ=1;
_nop_();
DQ=0;
_nop_();
_nop_();
DQ=1;
_nop_();
temp>>=1;
if(DQ)
temp|=0x80;
delay(60);
}
return(temp);
}
void Write_OneChar(uchar dat) //寫一個(gè)字節(jié)
{
uchar i;
for(i=0;i<8;i++)
{
DQ=0;
_nop_();
DQ=dat&0x01;
delay(10);
DQ=1;
dat>>=1;
}
}
int ReadTemp1() //讀取溫度
{
uchar Temp1L=0;
uchar Temp1H=0;
int t;
Init_DS18B20();
Write_OneChar(0xCC);
Write_OneChar(0x44);
delay(250);
LED = 0;
Init_DS18B20();
Write_OneChar(0xCC);
Write_OneChar(0xBE);
Temp1L=Read_OneChar();
Temp1H=Read_OneChar();
if(Temp1H&0xF0) //顯示負(fù)數(shù)
{
Temp1L=~Temp1L;
Temp1H=~Temp1H;
t=(Temp1H*256+Temp1L)/16*(-1)-1;
}
else
t=(Temp1H*256+Temp1L)*0.0625;
return(t);
}
void display()
{
wendu=ReadTemp1();
delay(100);
if(wendu<0)
{
wendu=-wendu;
disdata[0]='-';
}
else
disdata[0]=wendu/1000+0x30;//百位數(shù)
disdata[1]=wendu%1000/100+0x30;//十位數(shù)
disdata[2]=wendu%100/10+0x30;//個(gè)位數(shù)
disdata[3]=wendu%10+0x30;//小數(shù)位
write_com(0xc2);
write_data(disdata[0]);
write_com(0xc3);
write_data(disdata[1]);
write_com(0xc4);
write_data(disdata[2]);
write_com(0xc5);
write_data(disdata[3]);
}
void main()
{
init();
while(1)
{
ReadTemp1();
display();
delay(800);
}
}
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