硬件电路图和题目;

LED1-LD8是 P2口8个管脚

mian.c

#include<reg52.h>


sbit But1=P3^1	;
sbit But2=P3^0	 ;
sbit But3=P3^2	  ;
sbit But4=P3^3	  ;


sbit LED1 =P2^0	  ;
sbit LED2 =P2^1	  ;
sbit LED3 =P2^2	  ;
sbit LED4 =P2^3	  ;


#define PRESS_1 1
#define PRESS_2 2
#define PRESS_3 3
#define PRESS_4 4
#define UNPRESS_0 0

typedef unsigned int u16;
typedef unsigned char u8;

void delay_10us(u16 n)
{
 	while(n--);
}

press_scan(u8 mode)
{
	int key=1;
	if(key=1||(But1==0||But2==0||But3==0||But4==0))
	{
	key=0;
		delay_10us(500)	;
		if(But1==0)
		{
			mode=PRESS_1;
		}
			if(But2==0)
		{
			mode=PRESS_2