視頻教程：https://www.bilibili.com/video/BV1m741187ga

什么是網(wǎng)紅按鈕？

51內(nèi)核單片機(jī)定時(shí)器的計(jì)算（以12M晶振為例）； 晶振 12MHz =12000000Hz 時(shí)鐘周期 1/12000000 s（晶振的倒數(shù)） 機(jī)器周期是12/12000000 s (標(biāo)準(zhǔn)框架下51單片機(jī)一個(gè)機(jī)器是12個(gè)時(shí)鐘周期) 因?yàn)槎〞r(shí)器是每個(gè)機(jī)器周期加1所以定時(shí)時(shí)間為 N*時(shí)鐘機(jī)器周期時(shí)間=所定時(shí)間T 所以要經(jīng)過的機(jī)器周期是N*(12/12000000 s)=T N=t/(12/12000000 ) 初值等于 65536-N（因?yàn)?6位的定時(shí)器65535再加1才溢出） 例如： 需要定時(shí)1ms=0.001s =時(shí)間(s)*(晶振/12) 0.001/(12/12000000 )=0.001*(12000000 /12)=0.001*1000000=1000 初值y=65536-1000=64536=0XFC18

#include "reg52.h"
#define uchar unsigned char
#define uint unsigned int
#define SEG P0
sbit SCAN1 = P2^0;
sbit SCAN2 = P2^1;
sbit SCAN3 = P2^2;
sbit SCAN4 = P2^3;
sbit key = P3^0;
sbit Bepp = P3^7;
uchar number;
uchar flag;
uchar distab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};
int display=0;//數(shù)碼管刷新
int The_Time;//顯示時(shí)間 單位10ms
int dis_value;//計(jì)數(shù)頻率 10ms
void delay(uint j)                        //1ms
{
        uchar i=250;
        for(;j>0;j--)
{
                while(--i);
                i=249;
                while(--i);
                i=250;
        }
}


void Key_Scan()
{
	if(key==0)
	{
		delay(20);
		if(key==0)
		{
			while(key==0);
			if(flag==0)
			{
				flag=1;
				The_Time = 0;
			}else
			{
				flag=0;
			}
		}
	}
	
}


void Key_INT( )  interrupt 0  // 這里0對(duì)應(yīng)下表
{
	Bepp = ~ Bepp;
	  
				if(flag==0)
			{
				flag=1;
				The_Time = 0;
			}else
			{
				flag=0;
			}
}

void main()
{
	TMOD |= 0x01;	  //開啟定時(shí)器0  0x10時(shí)使用定時(shí)器1  0x11時(shí)啟動(dòng)兩個(gè)
	TH0=0XFC;	//給定時(shí)器賦初值，定時(shí)1ms   TH1
	TL0=0X18;	 //TL1
	EA=1;            //總中斷打開
	ET0=1;           //定時(shí)器0中斷打開    ET1
	TR0=1;           //定時(shí)器0開關(guān)打開    TR1
	EX0=1;       //外部中斷0開()  EX1 為外部中斷1 (P3^3)
	IT0=1;        //低電平觸發(fā)   IT1為中斷1
	while(1)
	{
		

		
	}
	
}


void Timer0() interrupt 1     //參考上圖  定時(shí)器1時(shí)為3
{
	static uint i;   //定義一個(gè)自變形變量
	TH0=0XFC;	//給定時(shí)器賦初值，定時(shí)1ms    TH1
	TL0=0X18;   //TL1
	i++;
	dis_value++;
	if(i==2)
	{
	i=0;
	SEG = 0XFF;
	switch(number)
	{

     case 0:SCAN4=1;SCAN3=0;SCAN2=0;SCAN1=0;SEG=distab[The_Time%10];break;
	
     case 1:SCAN4=0;SCAN3=1;SCAN2=0;SCAN1=0;;SEG=distab[The_Time/10%10];break;

     case 2:SCAN4=0;SCAN3=0;SCAN2=1;SCAN1=0;SEG=distab[The_Time/100%10]& 0x7f;break;

     case 3:SCAN4=0;SCAN3=0;SCAN2=0;SCAN1=1;;SEG=distab[The_Time/1000];break;

     default:break;
			
    }		
		number++;
    if(number>3)number=0;
	}	
	
	
	if(dis_value==10)
	{
		dis_value = 0;
		
		if(The_Time