51单片机A/D转换接口扩展，做一个16进制显示的电压表

遇到的问题如下：第二个数码管不亮，电平跳变都是对的。

如果在中断的P1，P2赋值那一块加上死循环两个数码管就都能亮了，

但是不能时刻测电压值了，纠结。

道编程如下：

#include

unsigned char tab[16] = {

0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,

0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};

unsigned char xdata *ADC;

unsigned char num, s, g, sum;

void delay(unsigned int Delay)

{

unsigned int i;

for(;Delay;Delay--) for(i=0;i<54;i++);

}

void main()

{

IT0 = 1; EX0 = 1; EA = 1;

ADC = 0xf8fb;

*ADC = 0;

while(1) {

P2 = 0x02; P1 = tab[s]; delay(1); P2 = 0xf9;

P2 = 0x04; P1 = tab[g]; delay(1); P2 = 0xf9;

}

}

void A() interrupt 0

{

num = *ADC;

s = num / 16;

g = num % 16;

*ADC = 0;

}

试试看。