DS18B20测温度在数码管显示不出来

只看该作者 · 2014-7-23 14:28

新手学习51单片机，虽然编译没问题，可是烧到板子里没反应，不知道是哪里出了问题，求指教  #include<reg51.h>
#include<math.h>
#include<intrins.h>

unsigned char code tab[]={0x3f,0x06,0x5b,
0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39
,0x5e,0x79,0x71,0x00,0x40};
sbit DQ=P3^3;

unsigned char dat;
unsigned char tempL=0;
   unsigned char tempH=0;
float temperature;

void delay(unsigned int count){
unsigned int i;
i=0;
while(i<count){
i++;

}return;
}

void delay1(void){
int k;
for(k=0;k<400;k++);
}

void display(int k){
P2=0xfe;
P0=tab[k/1000];
delay1();
P2=0xfd;
P0=tab[k%1000/100];
delay1();
P2=0xfb;
P0=tab[k%100/10];
delay1();
P2=0xf7;
P0=tab[k%10];
delay1();
P2=0xff;}

void init(){
unsigned char x=0;
DQ=1;
delay(8);
DQ=0;
delay(85);
DQ=1;
delay(14);
}

unsigned char readone(){
unsigned char i=0;
unsigned char dat=0;
for(i=8;i>0;i--){
DQ=1;
delay(1);
DQ=0;
dat>>=1;
DQ=1;
if(DQ){
dat|=0x80;
delay(4);
}
}return(dat);
}

void  writeone(unsigned char dat){
unsigned char i=0;
for(i=8;i>0;i--){
DQ=0;DQ=dat&0x01;
delay(5);
DQ=1;
dat>>=1;
}
delay(4);}

readtem(void){
init();
writeone(0xcc);
writeone(0x44);
delay(125);
init();
writeone(0xcc);
writeone(0xbe);
tempL=readone();
tempH=readone();
temperature=((tempH*256)+tempL)*0.0625;
delay(200);
return(temperature);

}

void main(){
float i;
while(1){
i=readtemperature();
display(i);}}