//用二極管測量溫度,并且在數(shù)碼管上顯示出來.溫度范圍是(0~~99)
//溫度上限報警為50度,超過此溫度就在數(shù)碼管上顯示兩個EE.ADC0804
//與單片機(jī)的接口電路如書上所示.
#include<at89x52.h>
unsigned char disbuf[2];
unsigned char shiwei,gewei;
displaybrush()
{unsigned char seg7code[11]={0x3f,0x06,0x5b,0x4f,0x66, 
                           0x6d,0x7d,0x07,0x7f,0x6f,0x79}; 
static unsigned char j;
P1=seg7code[disbuf[j]];
if(++j>2)j=0;
if(CY==0){P2_0=0;P2_1=1;}
else{P2_0=1;P2_1=0;}
CY=~CY;}
display()
{disbuf[0]=shiwei;
 disbuf[1]=gewei;}
main()
{unsigned char getdata;
 unsigned char x;
 TMOD=0x01; 
 TH0=(65536-4000)/256; 
 TL0=(65536-4000)%256; 
 TR0=1; 
 ET0=1; 
 EA=1; 
 while(1){P3_0=0;
          P3_6=0;
		  for(x=0;x<255;x++);
		  P3_0=1;
		  P3_6=1;
		  while(P3_3==1);
		  P3_0=0;
		  P3_7=0;
		  getdata=P0;
		  P3_7=1;
		  shiwei=getdata/10;
		  gewei=getdata%10;}
          if(shiwei>=5){gewei=10;shiwei=10;}
}
void inter(void) interrupt 1
{EA=0;
 TR0=0;
TH0=(65536-4000)/256; 
 TL0=(65536-4000)%256;
 TR0=1;
 ET0=1; 
 EA=1; 
while(TF0==0)
 {displaybrush();
  display();}
}