51单片机AD转换代码原理图参考

#include "reg52.h"

#define uchar unsigned char
#define uint unsigned int
	
sbit ADC_RD = P3^3;
sbit ADC_WR = P3^4;
sbit ADC_INT = P3^5;

uchar ledcode[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0Xbf};
uchar str[]={0,0,0,0};

uchar cnt;


void TIME_Init()
{
	TMOD=0X21;
	TH0=0X3c;
	TL0=0Xb0;
	ET0=1;
	EA=1;
	TR0=1;
}

void display(void)
{
	uchar t;
		
	P2=0x01;
	P0=ledcode[str[0]]&0x7f;
	for(t=0;t<150;t++);
	
	P2=0x02;
	P0=ledcode[str[1]];
	for(t=0;t<150;t++);
	
	P2=0x04;
	P0=ledcode[str[2]];
	for(t=0;t<150;t++);
	
	P2=0x08;
  P0=ledcode[str[3]];
	for(t=0;t<150;t++);

}

uchar ADCStart()
{
	uchar a;

	ADC_WR=0;
	ADC_WR=1;
	while(ADC_INT);

	ADC_RD=0;
	a=P1;
	ADC_RD=1;	
	
	return a;
}



void main()
{
	uint Data;
	TIME_Init();
	while(1)
	{
		display();
		if(cnt==20)
		{
			Data=ADCStart()*100.0*5/255;
			str[0]=Data/100%10;
			str[1]=Data/10%10;	
			str[2]=Data%10;
		}		
	}
}

void t0ser() interrupt 1   using 1
{

	TH0=0X3c;
	TL0=0Xb0;	
	cnt++;

}