51单片机八位数码管时钟电路仿真

电路图文件以及详细视频介绍请到B站评论区拿取
https://www.bilibili.com/video/BV1Ht4y1975h
仿真电路图

系统设计
1、方案(系统结构框图、器件选型)

器件选型有：AT89C51模块，八位阳极数码管显示模块，两个独立按键模块，还有P1口作为I/O口需要外加上拉电阻的电阻排，由于仿真的单片机模块内有时钟电路以及复位电路，这里省略了。

2、硬件设计与分析

电路原理图如图所示，P0口作为I/O口时需要外加上拉电阻，外接了一个电阻排，P2口接两个锁存器，分别控制数码管的位选和段选，给它的使能端口LE送高电平就开始工作，还要注意数码管采用的是共阴极接法。
这两个锁存器的工作原理是通过单片机控制。
先打开一个锁存器,选择一个位码,然后关闭,再打开另一个锁存器,选择一个要显示的断码, 采用独立按键接口电路控制8位共阴极数码管，采用中断方式K1按下调时，K2按下时调分，数码管初始显示时间为08-30-59.

3、软件设计与分析（流程图、代码）
流程图如下：

下面是代码：

#include <reg51.h>

sbit key1 = P1^0;
bit flag1s = 0;
bit KeySta = 1;
unsigned char hour = 8;
unsigned char minute = 30;
unsigned char second = 59;
unsigned char mode = 0;
void FreshTime();
void TimeInit();
void IntInit();
void InitLedBuff();
void keyscan();
  
unsigned char code LedChar[] = {  //共阴数码管显示字符转换表
    0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,
    0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x40,0x00};
unsigned char LedBuff[8] = {  //数码管显示缓冲区
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff};

void main()
{
  TimeInit();
  IntInit();
  InitLedBuff();
  while(1)//显示内容处理
  {
    if(flag1s&&!mode) //时间显示模式
    {
      flag1s = 0;
      FreshTime();
    }
    else if(mode == 1)  //校准分钟
    {
      LedBuff[0] = 17;
      LedBuff[1] = 17;
      LedBuff[4] = 17;
      LedBuff[5] = 17;//不显示
	  LedBuff[6] = 17;
      LedBuff[7] = 17;
      LedBuff[2] = minute/10;
      LedBuff[3] = minute%10;
    }
    else if(mode == 2)  //校准小时
    {
      LedBuff[2] = 17;
      LedBuff[3] = 17;
      LedBuff[4] = 17;
      LedBuff[5] = 17;//不显示
	   LedBuff[6] = 17;
      LedBuff[7] = 17;
      LedBuff[0] = hour/10;
      LedBuff[1] = hour%10;
    }
    else if(mode == 3)  //校准完成重新显示
    {
      InitLedBuff();
      mode = 0;
    }
    keyscan();
  }
}

void InitLedBuff()//初始化时间到显示缓冲区
{
  LedBuff[0] = hour/10;
  LedBuff[1] = hour%10;
  LedBuff[2] = minute/10;
  LedBuff[3] = minute%10;
  LedBuff[4] = second/10;
  LedBuff[5] = second%10;
}
void FreshTime()//刷新时间到显示缓冲区
{
  second++;
  if(second == 60)//进位
  {
    second = 0;
    minute++;
    LedBuff[2] = minute/10;
    LedBuff[3] = minute%10;
    if(minute == 60)//进位
    {
      minute = 0;
      hour++;
      if(hour == 24)
        hour = 0;
      LedBuff[0] = hour/10;
      LedBuff[1] = hour%10;
    }  
  }
  LedBuff[4] = second/10;
  LedBuff[5] = second%10;
}

void TimeInit()//定时器初始化
{
  TMOD = 0X11;    //设置定时器为模式1
  TL0 = 0xB0; 
  TH0 = 0x3C;     //定时初值 50ms
  TL1 = 0x18;		//
TH1 = 0xFC;		//定时初值 1ms
  TR0 = 1;    //定时器0开始计时
  TR1 = 1;    //定时器1开始计时
  ET1 = 1;    //使能定时器1
  ET0 = 1;    //使能定时器0
  PT0 = 1;    //提高计时准确性，提高定时器0中断优先级
  EA = 1;     //打开总中断
}
void IntInit()//外部中断初始化
{
  IT0 = 1;     //下降沿触发
  EX0 = 1;    //使能外部中断0
}

void keyscan() //按键扫描及处理
{
  static bit backup = 1;
  if (KeySta != backup)  //当前值与前次值不相等说明此时按键有动作
  {
    if (backup == 0)   //如果前次值为0，则说明当前是弹起动作
    {
      if(mode == 1)   //校准分钟时，分钟加一
      {
        minute++;
        if(minute==60)
          minute = 0;
      }
      else if(mode == 2)    //校准小时，小时加一
      {
        hour++;
        if(hour==24)
          hour = 0;
      }
    }
    backup = KeySta;   //更新备份为当前值，以备进行下次比较
  }
}
void Int0() interrupt 0 
{
  mode++;
  if(mode == 4)
  {
    mode = 0;
  }
}
void Ledfresh() //数码管显示刷新
{
  static unsigned char i = 0;
  switch(i)
  {
    case 0 : P2 = ~(0x01<<i);P0 = LedChar[LedBuff[i]];i++;break;
    case 1 : P2 = ~(0x01<<i);P0 = LedChar[LedBuff[i]];i++;break;
    case 2 : P2 = ~(0x01<<i);P0 = 0x40;i++;break;//时分间隔线
    case 3 : P2 = ~(0x01<<i);P0 = LedChar[LedBuff[2]];i++;break;
    case 4 : P2 = ~(0x01<<i);P0 = LedChar[LedBuff[3]];i++;break;
    case 5 : P2 = ~(0x01<<i);P0 = 0x40;i++;break;//分秒间隔线
	case 6 : P2 = ~(0x01<<i);P0 = LedChar[LedBuff[4]];i++;break;
	case 7 : P2 = ~(0x01<<i);P0 = LedChar[LedBuff[5]];i=0;break;
  }
}
void Time0() interrupt 1 // 50ms 
{
  static unsigned char n = 0;
  TL0 = 0xB0;
  TH0 = 0x3C;
  n++;
  if(n==20)
  {
    n=0;
    flag1s = 1;//1s标志位
  }
}

void Time1() interrupt 3  // 1ms
{
  static unsigned char keybuff = 0xff;
  TL1 = 0x18;		//
	TH1 = 0xFC;		//定时初值 1ms
  Ledfresh();
  keybuff = (keybuff<<1)|key1;
  if (keybuff == 0x00)
  {   //连续8次扫描值都为0，即16ms内都只检测到按下状态时，可认为按键已按下
      KeySta = 0;
  }
  else if (keybuff == 0xFF)
  {   //连续8次扫描值都为1，即16ms内都只检测到弹起状态时，可认为按键已弹起
      KeySta = 1;
  }
  else
  {}  //其它情况则说明按键状态尚未稳定，则不对KeySta变量值进行更新
}
//电路图文件以及详细视频介绍请到B站评论区拿取https://www.bilibili.com/video/BV1Ht4y1975h

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