3位显示。实测电压3.39V，显示006.？


最大电压值5V  显示005、

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#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
sbit eoc=P3^3;//转换标志 高有效
sbit wr=P3^6;
sbit rd=P3^7;
uchar code duan[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
uchar code wei[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
void smg(uchar d,w);
void adc();
void timer();
uint getdata;
void delay(uint t)
{
uchar a;
while(t--)
{
  for(a=0;a<75;a++){;}
}
}
main()
{
timer();
while(1)
{
  adc();  
}
}
void smg(uchar d,w)
{
P2=duan[d]; //送段数据.
// delay(1);   //亮
P1=wei[w];  //送位数据
delay(1);   //给1ms延时.如果延时久，跟跑马灯似的....
P1=0xff;    //共阴位0开、1关  
}
void adc()
{
wr=0;
wr=1;
wr=0;
rd=1;
wr=0;
while(eoc==1){;}//等待转换结束
rd=0;
// wr=0;
getdata=P0;
rd=1;
// wr=0;
}
void timer()
{
TMOD=0X01;
TH0=0XFC;
TL0=0X18;
ET0=1;
TR0=1;
EA=1;
}
void time()interrupt 1
{
TH0=0Xfc;
TL0=0X18;
   smg(getdata/100,0);
   getdata=getdata%10;
  smg(getdata/10,1);
  smg(getdata%10,2);
}

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