单片机课程实验-秒表实现

#include<reg51.h> typedef unsigned int uint; //定义无符号整形和字符型 typedef unsigned char uchar; uchar led[] = {0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90}; //共阳数码管 0 - 9 uchar led1[] = {0x40,0x79,0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10}; //共阳数码管 0 - 9 加小数点 uchar second; //秒数 uchar key; //按键次数 uint t; //用来计数,每500，代表0.1s sbit keyif = P3^7; //按键接口 void delay(){ //延时函数，用于消除抖动 uchar i,j; for(i=0;i<255;i++){ for(j=0;j<100;j++); } } void init(void) //初始化 { TMOD = 0x02; //0000 0010 使用方式二 second = 0; //秒数初始化为0 EA = 1; //总中断，定时器0中断允许 ET0 = 1; //允许定时器0中断 key = 0; //按键次数初始化为0 t = 0; //计数初始化为0 } void main(){ init(); P0 = led1[second/10]; P2 = led[second%10]; while(1){ if(keyif == 0){ delay();//消除抖动 if(keyif == 0){ key++; switch(key){ case 1: //按一次，计时器开始 TH0 = 0x38; TL0 = 0x38; //200us,也就是0.2ms TR0 = 1; break; case 2: //按两次，暂停定时器 t = 0; TR0 = 0; break; case 3: //按三次，停止计时，数据清零 key = 0; second = 0; P0 = led1[0]; P2 = led[0]; break; } while(keyif == 0); //若一直按下，使其停留 } } } } void timer() interrupt 1 { TR0 = 0; //停止计时 t++; if(t == 500){ second++; P0 = led1[second/10]; P2 = led[second%10]; t = 0; } if(second == 99){ //当计数到9.9秒，重新开始计时 second = 0; key = 1; //相当于重新开始计时 } TR0 = 1; //继续启动计时器 }