第6章智能电子钟的设计6.1 功能要求1. 设计要求以AT89C51单片机为核心，制作一个LCD显示的智能电子钟：(1) 计时：秒、分、时、天、周、月、年。

(2) 闰年自动判别。

(3) 五路定时输出，可任意关断（最大可到16路）。

(4) 时间、月、日交替显示。

(5) 自定任意时刻自动开/关屏。

(6) 计时精度：误差≤1秒/月（具有微调设置）。

(7) 键盘采用动态扫描方式查询。

所有的查询、设置功能均由功能键K1、K2完成。

2. 工作原理本设计采用市场上流行的时钟芯片DS1302进行制作。

DS1302是DALLAS公司推出的涓流充电时钟芯片，内含一个实时时钟/日历和31字节静态RAM，可以通过串行接口与计算机进行通信，使得管脚数量减少。

实时时钟/日历电路能够计算2100年之前的秒、分、时、日、星期、月、年的，具有闰年调整的能力。

DS1302时钟芯片的主要功能特性：(1) 能计算2100年之前的年、月、日、星期、时、分、秒的信息；每月的天数和闰年的天数可自动调整；时钟可设置为24或12小时格式。

(2) 31B的8位暂存数据存储RAM。

(3) 串行I/O口方式使得引脚数量最少。

(4) DS1302与单片机之间能简单地采用同步串行的方式进行通信，仅需3根线。

(5) 宽范围工作电压2.0-5.5V。

(6) 工作电流为2.0A时，小于300nA。

(7) 功耗很低，保持数据和时钟信息时功率小于1mW。

6.2 方案论证6.3 系统硬件电路的设计……6.4 系统程序的设计#include<reg51.h>#include<lcd.h>#include<ds1302.h>#define uchar unsigned char #define uint unsigned intsbit key1=P3^0;//设置键sbit key2=P3^3;//调节键加sbit key3=P3^6;//设置键减uchar second,minute,hour;uchar day,week,month,year;uchar pos_flag=0;uchar keyflag=0;//按键标志位//函数声明uchar read1302(uchar add); //读地址、数据void write1302(uchar add,uchar date); //写入地址、数据void write_com_date(uchar add,uchar date);void init_lcd();void init_ds1302();void delay(uchar time);void Disp_1602(uchar x,uchar y,uchar *p);void keyscan();void settime();void settime(){write1302(0x8e,0x00); //关闭写保护 write1302(0x80,second/10*16+second%10); //秒write1302(0x82,minute/10*16+minute%10); //分write1302(0x84,hour/10*16+hour%10); //时write1302(0x86,day/10*16+day%10); //日write1302(0x88,month/10*16+month%10); //月write1302(0x8a,week/10*16+week%10); //星期write1302(0x8c,year/10*16+year%10); //年write1302(0x8e,0x80);}void display(){second=read1302(0x81);write_com_date(0xca,0x30+second%10);write_com_date(0xc9,0x30+second/10);minute=read1302(0x83);write_com_date(0xc7,0x30+minute%10); write_com_date(0xc6,0x30+minute/10);hour=read1302(0x85);write_com_date(0xc4,0x30+hour%10);write_com_date(0xc3,0x30+hour/10);day=read1302(0x87);write_com_date(0x8a,0x30+day%10);write_com_date(0x89,0x30+day/10);week=read1302(0x8b);write_com_date(0xcd,0x30+week%10);month=read1302(0x89);write_com_date(0x87,0x30+month%10);write_com_date(0x86,0x30+month/10);year=read1302(0x8d);write_com_date(0x84,0x30+year%10);write_com_date(0x83,0x30+year/10);}void keyscan() //修改调整时间日期{if(key1==0){delay(10);if(key1==0){pos_flag++;while(!key1);keyflag=1;switch(pos_flag){case 1:write_com(0x80+4); //年write_com(0x0f); //光标闪烁break;case 2:write_com(0x80+7); //月break;case 3:write_com(0x80+10); //日break;case 4:write_com(0x80+0x40+0x0d); //星期break;case 5:write_com(0x80+0x40+4); //时钟break;case 6:write_com(0x80+0x40+7); //分钟break;case 7:write_com(0x80+0x40+10); //秒钟break;default:break;}if(pos_flag==8) //pos_flag=8则退出调整{pos_flag=0;keyflag=0; //按键标识清零delay(5);settime();write_com(0x0c); // 关光标}}}if(key2==0) //调节加键，按下（低电平）就加{delay(15);if(key2==0){while(!key2);switch(pos_flag){case 1:year++;if(year==99)year=0;write_com_date(0x84,0x30+year%10);write_com_date(0x83,0x30+year/10);break;case 2:month++;if(month==13)month=1;write_com_date(0x87,0x30+month%10);write_com_date(0x86,0x30+month/10);break;case 3:day++;if((year%4==0)&&(month==2)) //闰年二月29天{if(day==30)day=1;}if((year%4!=0)&&(month==2)) //平年二月28天{if(day==29)day=1;}if(month==1||month==3||month==5||month==7||month==8||month==10||month==12) //大月31天{if(day==32)day=1;}if(month==4||month==6||month==9||month==11) //小月30天{if(day==31)day=1;}write_com_date(0x8a,0x30+day%10);write_com_date(0x89,0x30+day/10);break;case 4:week++;if(week==8)week=1;write_com_date(0xcd,0x30+week);break;case 5:hour++;hour=0;write_com_date(0xc4,0x30+hour%10);write_com_date(0xc3,0x30+hour/10);break;case 6:minute++;if(minute==60)minute=0;write_com_date(0xc7,0x30+minute%10);write_com_date(0xc6,0x30+minute/10);break;case 7:second++;if(second==60)second=0;write_com_date(0xca,0x30+second%10);write_com_date(0xc9,0x30+second/10);break;default:break;}}}if(key3==0){delay(15);if(key3==0){while(!key3);switch(pos_flag){case 1:year--;year=99;write_com_date(0x84,0x30+year%10);write_com_date(0x83,0x30+year/10);break;case 2:month--;if(month==0)month=12;write_com_date(0x87,0x30+month%10);write_com_date(0x86,0x30+month/10);break;case 3:day--;if((year%4==0)&&(month==2)) //闰年二月29天{if(day==0)day=29;}if((year%4!=0)&&(month==2)) //平年二月28天{if(day==0)day=28;}if(month==1||month==3||month==5||month==7||month==8||month==10||month==12) //大月31天{if(day==0)day=31;}if(month==4||month==6||month==9||month==11) //小月30天{if(day==0)}write_com_date(0x8a,0x30+day%10);write_com_date(0x89,0x30+day/10);break;case 4:week--;if(week==0)week=7;write_com_date(0xcd,0x30+week);break;case 5:hour--;if(hour==0)hour=24;write_com_date(0xc4,0x30+hour%10);write_com_date(0xc3,0x30+hour/10);break;case 6:minute--;if(minute==0)minute=59;write_com_date(0xc7,0x30+minute%10);write_com_date(0xc6,0x30+minute/10);break;case 7:second--;if(second==0)second=59;write_com_date(0xca,0x30+second%10);write_com_date(0xc9,0x30+second/10);break;default:break;.}}}}void main(){init_lcd();delay(2);init_ds1302();delay(2);Disp_1602(1,0,"20 - - week") ;Disp_1602(5,1,": :") ;while(1){if(keyflag==0){display();}keyscan();}}#ifndef _lcd_h_#define _lcd_h_#include <reg51.h>#define uchar unsigned char#define uint unsigned intsbit lcdrs=P2^0;sbit lcdrw=P2^1;sbit lcden=P2^2;void delay(uchar ms){uchar i;for(;ms>0;ms--)for(i=110;i>0;i--);}void write_com(uchar com) //写指令{lcden=0;lcdrs=0;lcdrw=0;P0=com;delay(1);lcden=1;delay(1);lcden=0;}void write_data(uchar date) //写数据{lcden=0;lcdrs=1;lcdrw=0;delay(1);lcden=1;delay(1);lcden=0;}void write_com_date(uchar add,uchar date) {write_com(add);delay(1);write_data(date);}void Disp_1602(uchar x,uchar y,uchar *p) {while(*p){if(y==0) x|=0x80;else x|=0xc0;write_com(x);delay(5);write_data(*p);x++;p++;}}void init_lcd(){delay(15);write_com(0x38);delay(15);write_com(0x38);write_com(0x38);write_com(0x0c);write_com(0x06);write_com(0x01);}#endif#ifndef _ds1302_h_#define _ds1302_h_#include <reg51.h>#define uchar unsigned char#define uint unsigned intsbit sclk=P1^1;sbit io=P1^0;sbit rst=P1^2;sbit ACC_7=ACC^7;void write1302(uchar add,uchar date) //写入地址、数据{uchar i;rst=0;sclk=0;rst=1;for(i=0;i<8;i++){sclk=0;io=add&0x01;add>>=1;sclk=1;}for(i=0;i<8;i++){sclk=0;io=date&0x01;date>>=1;sclk=1;}rst=0;}uchar read1302(uchar add) //读地址、数据{uchar i,dat1,dat2;rst=0;sclk=0;rst=1;for(i=0;i<8;i++){sclk=0;io=add&0x01;add>>=1;sclk=1;}for(i=0;i<8;i++){ACC_7=io;sclk=1;ACC>>=1;sclk=0;}rst=0;sclk=1;dat1=ACC;dat2=dat1/16;dat1=dat1%16;dat1=dat2*10+dat1;return dat1;}void init_ds1302(){if(((read1302(0x81))&0x0f)==1){write1302(0x8e,0x00); //关闭写保护 }}#endif……6.5调试及性能分析6.5.1 调试与测试……6.5.2 性能分析。