void writecommandtods18b20(unsigned char command)
{
unsigned char i;
unsigned char j;
　
for(i=0;i<8;i++)
{
if((command & 0x01)==0)
{
DQ=0;
for(j=35;j>0;j--);
DQ=1;
}
else
{
DQ=0;
for(j=2;j>0;j--);
DQ=1;
for(j=33;j>0;j--);
}
command=_cror_(command,1);
}
}
　
unsigned char readdatafromds18b20(void)
{
unsigned char i;
unsigned char j;
unsigned char temp;
　
temp=0;
for(i=0;i<8;i++)
{
temp=_cror_(temp,1);
DQ=0;
_nop_();
_nop_();
DQ=1;
for(j=10;j>0;j--);
if(DQ==1)
{
temp=temp | 0x80;
}
else
{
temp=temp | 0x00;
}
for(j=200;j>0;j--);
}
return(temp);
}
　
void main(void)
{
TMOD=0x01;
TH0=(65536-4000)/256;
TL0=(65536-4000)%256;
ET0=1;
EA=1;
　
while(resetpulse());
writecommandtods18b20(0xcc);
writecommandtods18b20(0x44);
TR0=1;
while(1)
{
;
}
}
　
void t0(void) interrupt 1 using 0
{
unsigned char x;
unsigned int result;
　
TH0=(65536-4000)/256;
TL0=(65536-4000)%256;
if(displaycount==2)
{
P0=displaycode[displaybuf[displaycount]] | 0x80;
}
else
{
P0=displaycode[displaybuf[displaycount]];
}
P2=displaybit[displaycount];
displaycount++;
if(displaycount==8)
{
displaycount=0;
}
　
timecount++;
if(timecount==150)
{
timecount=0;
while(resetpulse());
writecommandtods18b20(0xcc);
writecommandtods18b20(0xbe);
readdata[0]=readdatafromds18b20();
readdata[1]=readdatafromds18b20();
for(x=0;x<8;x++)
{
displaybuf[x]=16;
}
sflag=0;
if((readdata[1] & 0xf8)!=0x00)
{
sflag=1;
readdata[1]=~readdata[1];
readdata[0]=~readdata[0];
result=readdata[0]+1;
readdata[0]=result;
if(result>255)
{
readdata[1]++;
}
}
readdata[1]=readdata[1]<<4;
readdata[1]=readdata[1] & 0x70;
x=readdata[0];
x=x>>4;
x=x & 0x0f;
readdata[1]=readdata[1] | x;
x=2;
result=readdata[1];
while(result/10)
{
displaybuf[x]=result%10;
result=result/10;
x++;
}
displaybuf[x]=result;
if(sflag==1)
{
displaybuf[x+1]=17;
}
x=readdata[0] & 0x0f;
x=x<<1;
displaybuf[0]=(dotcode[x])%10;
displaybuf[1]=(dotcode[x])/10;
while(resetpulse());
writecommandtods18b20(0xcc);
writecommandtods18b20(0x44);
}
}

  

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