程序：
#include
#define uchar unsigned char
#define uint unsigned int
//各数字的数码管段码（共阴）
![](https://wkrtcs.bdimg.com/rtcs/image?w=358.33&md5sum=42e998c5748926554c300d964b0a004e&sign=6a428410fb&rtcs_flag=2&rtcs_ver=4&l=webapp&bucketNum=374&ipr={"t":"img","r":"r_1","w":"358.33","h":"257.67","dataType":"png","c":"word/media/image1.png","imgOriW":1053,"imgOriH":758})
uchar code DSY_CODE[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
sbit CLK=P1^3; //时钟信号
sbit ST=P1^2; //启动信号
sbit EOC=P1^1; //转换结束信号
sbit OE=P1^0; //输出使能
//延时
void DelayMS(uint ms)
{
uchar i;
while(ms--) for(i=0;i<120;i++);
}
//显示转换结果
void Display_Result(uchar d)
{
P2=0xf7; //第4个数码管显示个位数
P0=DSY_CODE[d%10];
DelayMS(5);
P2=0xfb; //第3个数码管显示十位数
P0=DSY_CODE[d%100/10];
DelayMS(5);
P2=0xfd; //第2个数码管显示百位数
P0=DSY_CODE[d/100];
DelayMS(5);
}
//主程序
void main()
{
TMOD=0x02; //T1工作模式2
TH0=0x14;
TL0=0x00;
IE=0x82;
TR0=1;
P1=0x3f; //选择ADC0809的通道3（0111）（P1.4~P1.6）
while(1)
{
ST=0;ST=1;ST=0; //启动A/D转换
while(EOC==0); //等待转换完成
OE=1;
Display_Result(P3);
OE=0;
}
}
//T0定时器中断给ADC0809提供时钟信号
void Timer0_INT() interrupt 1
{
CLK=~CLK;
}
硬件图：
![](https://wkrtcs.bdimg.com/rtcs/image?w=584.00&md5sum=42e998c5748926554c300d964b0a004e&sign=6a428410fb&rtcs_flag=2&rtcs_ver=4&l=webapp&bucketNum=374&ipr={"t":"img","w":"584.00","h":"420.87","dataType":"png","c":"word/media/image2.png","imgOriW":1053,"imgOriH":758})
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