讲解单片机99秒马表程序原理

Question

#include

unsigned char code dispcode[]={0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71,0x00};
unsigned char second;
unsigned char keycnt;
unsigned int tcnt;

void main(void)
{
unsigned char i,j;

TMOD=0x02;
ET0=1;
EA=1;
second=0;
P0=dispcode[second/10];
P2=dispcode[second%10];
while(1)
{
if(P3_5==0)
{
for(i=20;i>0;i--)
for(j=248;j>0;j--);
if(P3_5==0)
{
keycnt++;
switch(keycnt)
{
case 1:
TH0=0x06;
TL0=0x06;
TR0=1;
break;
case 2:
TR0=0;
break;
case 3:
keycnt=0;
second=0;
P0=dispcode[second/10];
P2=dispcode[second%10];
break;
}
while(P3_5==0);
}
}
}
}

void t0(void) interrupt 1 using 0
{
tcnt++;
if(tcnt==400)
{
tcnt=0;
second++;
if(second==100)
{
second=0;
}
P0=dispcode[second/10];
P2=dispcode[second%10];
}
}

Answer 1

#include <reg51.h> //头文件

unsigned char code dispcode[]={0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71,0x00}; //共阴极数码管显示0-F
unsigned char second; //参数 秒
unsigned char keycnt; //用于按键计次
unsigned int tcnt; //中断计次

void main(void)
{
unsigned char i,j;

TMOD=0x02; //定时器T0，定时方式，方式2
ET0=1; //开定时器中断
EA=1; //全局中断
second=0; //秒初始值为0
P0=dispcode[second/10]; //显示秒十位
P2=dispcode[second%10]; //显示秒个位
while(1)
{
if(P3_5==0) //按键按下
{
for(i=20;i>0;i--) //延时消抖
for(j=248;j>0;j--);
if(P3_5==0) //再次确认按下
{
keycnt++; //加1
switch(keycnt)
{
case 1: //如果为1，启动定时器
TH0=0x06;
TL0=0x06;
TR0=1;
break;
case 2: //如果为2 ，停止定时器
TR0=0;
break;
case 3: //如果为3，所有变量初始化
keycnt=0;
second=0;
P0=dispcode[second/10];
P2=dispcode[second%10];
break;
}
while(P3_5==0);
}
}
}
}

void t0(void) interrupt 1 using 0
{
tcnt++; //中断计次
if(tcnt==400) // 250us*400=1s
{
tcnt=0;
second++;
if(second==100) //如果秒等于100，秒设置成0
{
second=0;
}
P0=dispcode[second/10]; //显示十位
P2=dispcode[second%10]; //个位
}
}本回答被提问者和网友采纳