这是我的一个温度ds18b20的程序，有点问题，不能显示出来，

#include

#include
#define uint unsigned int
#define uchar unsigned char
***it rs=P2^6;
***it rw=P2^5;
***it sn=P2^7;
***it zx=P3^7;//温度总线

void delay(uint x)
{
  uint i,j;
  for(i=x;i>0;i--)
   for(j=110;j>0;j--);
}
void writecom(char com)
{
rs=0;
sn=0;
rw=0;
P0=com;
delay(5);
sn=1;
delay(5);
sn=0;
}
void writedate(char date)
{
rs=1;
sn=0;
rw=0;
P0=date;
delay(5);
sn=1;
delay(5);
sn=0;

}
void init()
{

writecom(0x38);
writecom(0x0c);
writecom(0x06);
writecom(0x01);
writecom(0x80);

}
unsigned char ds18b20init()
{
uchar i;
zx=0;
i=80;
while(i--);/
zx=1;
i=0;
while(zx)
{
i++;
if(i<5000)
return 0;

}
return 1;
}
void writebyte(char dat)
{
uchar i,j;
for(j=0;j<8;j++)
{
zx=0;
i++;
zx=dat&0x01;/
i=6;
while(i--);
zx=1;
dat>>=1;

}
}
uchar readbyte()
{
char byte,bi;
int i,j;
for(j=0;i<8;j++)
{
zx=0;
i++;
zx=1;
i++;
i++;/
bi=zx;
byte=(byte>>1)|(bi<<7);//
i=4;
while(i--);
}
return byte;
}
void changwendu()
{
ds18b20init();
delay(1);
writebyte(0xcc);
writebyte(0x44);
delay(100);

}
void reaswdcom()
{
ds18b20init();
delay(1);
writebyte(0xcc);
writebyte(0xbe);
}
int readwd()
{
int wd=0;
unsigned char h,d;
changwenducom();
readwdcom();
d=readbyte();
h=readbyte();
wd=h;
wd<<=8;
wd|=d;
return wd;

}
void display(int wd)
{
unsigned char datas[]={0,0,0,0,0};
float tp;
if(wd<0)
{
writecom(0x87);
writedate("-");
wd=wd-1;
wd=~wd;
tp=wd;
wd=tp*0.0625*100+0.5;
}
else
{
writecom(0x87);
writedate("+");
tp=wd;
wd=tp*0.0625*100+0.5;
}
datas[0] = wd / 10000;
datas[1] = wd % 10000 / 1000;
datas[2] = wd % 1000 / 100;
datas[3] = wd % 100 / 10;
datas[4] = wd % 10;

writecom(0x88);
writedate("0"+datas[0]);
writecom(0x89);
writedate("0"+datas[1]);
writecom(0x90);
writedate("0"+datas[2]);
writecom(0x91);
writedate("0"+datas[3]);
writecom(0x92);
writedate(".");
writecom(0x93);
writedate("0"+datas[4]);
writecom(0x94);
writedate("0"+datas[5]);
}
void main()
{
init();
while(1)
{
display(readwd());
}
}