|
实验板 K1按键 按一下 开始倒计时
K2按键 按一下 停止倒计时
单片机程序如下
- #include<reg51.h>
- sbit Key_UP=P3^2;
- sbit Key_DOWN=P3^3;
- unsigned char KeyV,TempKeyV;
- sbit P25=P2^5;//数码管第5位
- sbit P26=P2^6;//数码管第6位
- sbit P27=P2^7;//数码管第7位
- sbit JDQ=P3^7;//继电器
- unsigned int js;
- unsigned int ds;//倒计时初始时间
- unsigned char jsflag;
- static unsigned int i;
- unsigned char code LEDDis[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0xFF,0xBF};
- void Delay(unsigned int ii) //1MS
- {
- unsigned int jj;
- for(;ii>0;ii--)
- for(jj=0;jj<125;jj++)
- {;}
- }
- void main()
- {
- EA = 1; //允许CPU中断
- ET0 = 1; //定时器0中断打开
- ET1=1; //定时器1中断打开
- TMOD = 0x11; //设定时器0 1为模式1,16位模式
- TH0=0xB8;
- TL0=0x00; //设定时值为(20ms)
- TH1=0xdc; //设定时值为(10ms)
- TL1=0x00;
- TR0 = 1;
- TR1=1;
- ds=999;
- KeyV = 0;
- TempKeyV = 0;
- jsflag=0;
- while(1);
- }
- //定时器0中断外理中键扫描和显示
- void Key_Time0(void) interrupt 1 using 2
- {
- TH0=0xB8;
- TL0=0x00; //设定时值为20000us(20ms)
- if (!Key_UP)
- KeyV = 1;
- if (!Key_DOWN)
- KeyV = 2;
- if (KeyV!= 0) //有键按下
- {
- Delay(10); //延时防抖 按下10ms再测
- if (!Key_UP)
- TempKeyV = 1;
- if (!Key_DOWN)
- TempKeyV = 2;
- if (KeyV == TempKeyV) //两次值相等为确定接下了键
- {
- if (KeyV == 1){
- jsflag=0;
- if(ds==0){
- ds=600;
- }
- js=js+1;
- JDQ=0; //继电器吸合
-
- if(js==50){
- js=0;
- ds=ds-1;
-
- }
- }
- if(KeyV==2){
- jsflag=1;
- }
- }
- }
- if(jsflag==1){
- JDQ=1;
- }
- if(ds==0){
- JDQ=1;
- jsflag=1;
- KeyV=0;
- }
- }
- void disp_Time1(void) interrupt 3 using 3
- { TH1=0xdc;
- TL1=0x00;
- P0=LEDDis[ds/100];
- P25=0;
- Delay(2);
- P25=1;
- P0=LEDDis[(ds%100)/10];
- P26=0;
- Delay(2);
- P26=1;
- P0=LEDDis[ds%10];
- P27=0;
- Delay(2);
- P27=1;
-
- }
复制代码
|
|