以AT89C51单片机为核心,制作一个LCD显示的智能电子钟

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

#include

#include

#define uchar unsigned char #define uint unsigned int

sbit 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++;

if(hour==24)

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--;

if(year==0)

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)

day=30;

}

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

#define uchar unsigned char

#define uint unsigned int

sbit 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;

P0=date;

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);

delay(5);

write_com(0x38);

write_com(0x0c);

write_com(0x06);

write_com(0x01);

}

#endif

#ifndef _ds1302_h_

#define _ds1302_h_

#include

#define uchar unsigned char

#define uint unsigned int

sbit 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;