使用定时器(T1)和中断实现数码管999999倒计时
本次程序所需要定义4个全局变量,变量i用来每隔1ms刷新一个数码管,6ms刷新6个数码管。形成视觉暂留现象。变量b用来定时1s。变量a用来初始化数码管的值,初始值为999999.变量c用来消除无效位数字(就是当计时为99999最高位自动消去)
具体效果点击此处:www.bilibili.com/video/BV1KY411h71t/
#include<reg52.h>
sbit ENLED = P1^1;
sbit ADDR0 = P2^0;
sbit ADDR1 = P2^1;
sbit ADDR2 = P2^2;
unsigned char code LedChar[] = {
0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8,
0x80, 0x90, 0x88, 0x83, 0xC6, 0xA1, 0x86, 0x8E
};
unsigned char buff[] = {
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF
};
unsigned char i = 0;
unsigned int b = 0;
unsigned long a = 999999;
unsigned long c = 0;
void main()
{
ENLED = 0;
TMOD = 0x01;
TH1 = 0xF5;
TL1 = 0x55;
TR1 = 1;
EA = 1;
ET1 = 1;
while(1)
{
if(b>=1000)
{
b=0;
a--;
c++;
buff[0] =LedChar[a%10];
buff[1] =LedChar[a/10%10];
buff[2] =LedChar[a/100%10];
buff[3] =LedChar[a/1000%10];
buff[4] =LedChar[a/10000%10];
buff[5] =LedChar[a/100000%10];
}
}
}
void InterrupuTimer0() interrupt 1
{
b++;
TH1 = 0xF5;
TL1 = 0x55;
P0 = 0xFF;
switch(i)
{
case 0:if(c<=900000){ADDR2 = 0; ADDR1 = 0; ADDR0 = 0; i++; P0 =buff[5];break;}
case 1:if(c<=990000){ ADDR2 = 0; ADDR1 = 0; ADDR0 = 1; i++; P0 =buff[4];break;}
case 2:if(c<=999000){ADDR2 = 0; ADDR1 = 1; ADDR0 = 0; i++; P0 =buff[3];break;}
case 3:if(c<=999900){ ADDR2 = 0; ADDR1 = 1; ADDR0 = 1; i++; P0 =buff[2];break;}
case 4:if(c<=999990){ ADDR2 = 1; ADDR1 = 0; ADDR0 = 0; i++; P0 =buff[1];break;}
case 5:if(c<=999999){ ADDR2 = 1; ADDR1 = 0; ADDR0 = 1; i=0; P0 =buff[0];break;}
}
}
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