单片机学习10——独立按键

#include&lt;reg52.h&gt;

sbit LED1=P1^0;
sbit KEY1=P3^4;

void main()
{
	KEY1=1;
	while(1)
	{
	 	if(KEY1==0)	 //KEY1按下
		{
		 	LED1=0;	 //LED1被点亮
		}
		else
		{
		 	LED1=1;
		}
	}
}

按键

#include<reg52.h&gt;

#define uchar unsigned char
#define uint unsigned int

sbit LED1=P1^0;
sbit KEY1=P3^4;

sbit dula=P2^6;
sbit wela=P2^7;

uchar disnum;

uchar code table_duan[]={
0x3f,0x06,0x5b,0x4f,0x66,0x6d,
0x7d,0x07,0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};

void main()
{
	P0=0xfe;
	wela=1;
	wela=0;
	KEY1=1;
	while(1)
	{
	 	if(KEY1==0)	 //KEY1按下
		{
		 	LED1=0;	 //LED1被点亮
			disnum++;
			if(disnum==10)
			{
				disnum=0;
			}
			while(!KEY1);  //重要
		}
		else
		{
		 	LED1=1;
			P0=table_duan[disnum];
			dula=1;
			dula=0;
		}
	}
}

按键在闭合和断开的时候，触电会存在抖动的现象：

按键抖动时间是由按键的机械特性决定：

一般为5ms到10ms之间。

按键前沿抖动消除和按键后延抖动的消除：

#include<reg52.h&gt;

#define uchar unsigned char
#define uint unsigned int

sbit LED1=P1^0;
sbit KEY1=P3^4;

sbit dula=P2^6;
sbit wela=P2^7;

uchar disnum;

uchar code table_duan[]={
0x3f,0x06,0x5b,0x4f,0x66,0x6d,
0x7d,0x07,0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};

void delay(uchar);

void main()
{
	P0=0xfe;
	wela=1;
	wela=0;
	KEY1=1;
	while(1)
	{
	 	if(KEY1==0)	 //KEY1按下
		{
			delay(10);    //按键前沿抖动的消除
			if(KEY1==0)   //按键前沿抖动的消除
			{
			   LED1=0;	 //LED1被点亮
				disnum++;
				if(disnum==10)
				{
					disnum=0;
				}
				while(!KEY1);  //重要
				delay(10);	   //按键后延抖动的消除
				while(!KEY1);  //按键后延抖动的消除
			}		 	
		}
		else
		{
		 	LED1=1;
			P0=table_duan[disnum];
			dula=1;
			dula=0;
		}
	}
}


void delay(uchar x)
{
	uchar a, b;
	for(a=x;a&gt;0;a--)
	{
	 	for(b=200;b&gt;0;b--);
	}	
}