定义的全局变量adval不能动态的赋值，在程序最后加复位才能实现A/D动态显示效果，不加复位数码管只能静态显示，调节外部输入模拟量无效
#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit wr=P3^6;
sbit rd=P3^7;
sbit dula=P2^6;
sbit wela=P2^7;
uchar a,A1,A2,A2t,A3,adval;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71
};
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void main()
{
while(1)
{
start();
P1=0xff; //拉高
delay(20);
rd=0;
delay(10);
rd=1;
adval=P1;//p1口值（A/D输出的模拟量）赋给adval，adval交给display显示
delay(10);
A1=adval/100;
A2t=adval%100;
A2=A2t/10;
A3=A2t%10;
display(A1,A2,A3);
delay(10);
//复位
}
} |
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