DS18B20與數(shù)碼管程序

#include
#define uint unsigned int
#define uchar unsigned char
sbit DQ=P2^0;//P2^0
uchar code tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};//不帶小數(shù)點
uchar code tab1[]={0x40,0x79,0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10};//帶小數(shù)點
sbit wei0=P0^0;//P3^2
sbit wei1=P0^1;//P3^3
//sbit wei2=P1^2;
//sbit wei3=P1^3;
uchar disdata[2];
uint tvalue;
uchar tflag;
void delay(uint i)
{
while(i--);
}
void ds1820rst()//復位
{
DQ=1;
delay(4);
DQ=0;
delay(100);
DQ=1;
delay(40);
}
uchar ds1820rd()//讀數(shù)據(jù)
{
uchar i;
uchar dat=0;
for(i=8;i>0;i--)
{
DQ=0;
dat>>=1;
DQ=1;
if(DQ)
dat|=0x80;//dat=DQ;dat&=0x80;
delay(10);
}
return(dat);
}
void ds1820wr(uchar wdata)//寫數(shù)據(jù)
{
uchar i=0;
for(i=8;i>0;i--)
{
DQ=0;
DQ=wdata&0x01;
delay(10);
DQ=1;
wdata>>=1;
}
}
read_temp()/*讀取溫度值并轉換*/
{
uchar a,b;
ds1820rst();
ds1820wr(0xcc);//*跳過讀序列號*/
ds1820wr(0x44);//*啟動溫度轉換*/
ds1820rst();
ds1820wr(0xcc);//*跳過讀序列號*/
ds1820wr(0xbe);//*讀取溫度*/
a=ds1820rd();
b=ds1820rd();
tvalue=b;
tvalue<<=8;
tvalue=tvalue|a;
if(tvalue<0x0fff)
tflag=0;
else
{tvalue=~tvalue+1;
tflag=1;
}
tvalue=(tvalue*0.0625);//0.625溫度值擴大10倍，精確到1位小數(shù)
return(tvalue);
}


void ds1820disp()//溫度值顯示
{
disdata[0]=tvalue/10;//十位數(shù)
disdata[1]=tvalue%10;//個位數(shù)
wei0=0;
P1=tab[disdata[0]];
delay(250);
wei0=1;
wei1=0;
P1=tab[disdata[1]];
delay(250);
wei1=1;
}

void main()
{
while(1)
{

read_temp();//讀取溫度

ds1820disp();//顯示
}
}