1. DS1302介绍

•DS1302是由美国DALLAS公司推出的具有涓细电流充电能力的低功耗实时时钟芯片。它可以对年、月、日、周、时、分、秒进行计时，且具有闰年补偿等多种功能

•RTC(Real Time Clock)：实时时钟，是一种集成电路，通常称为时钟芯片

1. DS1302引脚介绍

1. 内部结构图

1. 寄存器定义

1. 时序定义

1. BCD码

•BCD码（Binary Coded Decimal‎），用4位二进制数来表示1位十进制数

•例：00010011表示13，1000 0101表示85，00011010不合法

•在十六进制中的体现：0x13表示13，0x85表示85，0x1A不合法

•BCD码转十进制：DEC=BCD/16*10+BCD%16; （2位BCD）

•十进制转BCD码：BCD=DEC/10*16+DEC%10; （2位BCD）

1. DS1302时钟的实现

1）程序

#include <REGX52.H>
#include "LCD1602.h"
#include "Delay.h"
#include "Ds1302.h"
#include "Key.h"#include "Timer0.h"void main ()
{LCD_Init();DS1302_Init();LCD_ShowString(1,1,"  -  -  ");LCD_ShowString(2,1,"  :  :  ");DS1302_SetTime();while(1){DS1302_ReadTime();//读取时间LCD_ShowNum(1,1,DS1302_Time[0],2);//显示年LCD_ShowNum(1,4,DS1302_Time[1],2);//显示月LCD_ShowNum(1,7,DS1302_Time[2],2);//显示日LCD_ShowNum(2,1,DS1302_Time[3],2);//显示时LCD_ShowNum(2,4,DS1302_Time[4],2);//显示分LCD_ShowNum(2,7,DS1302_Time[5],2);//显示秒}
}

DS1302.C

#include <REGX52.H>
//引脚定义sbit DS1302_SCLK=P3^6;
sbit DS1302_IO=P3^4;
sbit DS1302_CE=P3^5;//寄存器写入地址/指令命令
#define DS1302_SECOND 0x80
#define DS1302_MINUTE 0x82
#define DS1302_HOUR         0x84
#define DS1302_DATA         0x86
#define DS1302_MONTH     0x88
#define DS1302_DAY     0x8A
#define DS1302_YEAR     0x8C
#define DS1302_WP         0x8E//定义一个数组表示年月日时间
unsigned char DS1302_Time[]={23,02,11,20,55,55};
/*** @brief  DS1302初始化* @param  无* @retval 无*/
void DS1302_Init(void)
{DS1302_SCLK=0;DS1302_CE=0;
}/*** @brief  DS1302写入一个字节* @param  Command 命令字/地址* @param  Data 将要写入数据* @retval 无*/
void DS1302_WriteByte(unsigned char Command ,Data)
{ unsigned char i;DS1302_CE=1;for (i=0;i<8;i++){DS1302_IO=Command&( 0x01<<i);DS1302_SCLK=1;DS1302_SCLK=0;}for (i=0;i<8;i++){DS1302_IO=Data&( 0x01<<i);DS1302_SCLK=1;DS1302_SCLK=0;}DS1302_CE=0;
}
/*** @brief  DS1302读出一个字节* @param  Command 命令字/地址* @retval 读出的数据*/unsigned char DS1302_ReadByte( unsigned char Command)
{unsigned char i,Data=0x00;Command|=0x01;//指令转换为读指令DS1302_CE=1;for (i=0;i<8;i++){DS1302_IO=Command&( 0x01<<i);DS1302_SCLK=0;//根据时序表变换而来DS1302_SCLK=1;}for (i=0;i<8;i++){DS1302_SCLK=1;DS1302_SCLK=0;if(DS1302_IO){Data|=(0x01<<i);}        }DS1302_CE=0;DS1302_IO=0;//读取后将IO设置为0，否则读出的数据会出错return Data;
}
/*** @brief  DS1302设置时间，调用之后，DS1302_Time数组的数字会被设置到DS1302中* @param  * @retval */
void DS1302_SetTime(void)
{十进制转BCD码后写入DS1302_WriteByte(DS1302_WP,0x00);//解除保护DS1302_WriteByte(DS1302_YEAR,DS1302_Time[0]/10*16+DS1302_Time[0]%10);DS1302_WriteByte(DS1302_MONTH,DS1302_Time[1]/10*16+DS1302_Time[1]%10);DS1302_WriteByte(DS1302_DATA,DS1302_Time[2]/10*16+DS1302_Time[2]%10);DS1302_WriteByte(DS1302_HOUR,DS1302_Time[3]/10*16+DS1302_Time[3]%10);DS1302_WriteByte(DS1302_MINUTE,DS1302_Time[4]/10*16+DS1302_Time[4]%10);DS1302_WriteByte(DS1302_SECOND,DS1302_Time[5]/10*16+DS1302_Time[5]%10);DS1302_WriteByte(DS1302_DAY,DS1302_Time[6]/10*16+DS1302_Time[6]%10);DS1302_WriteByte(DS1302_WP,0x80);
}/*** @brief  DS1302读取时间，调用之后，DS1302中的数据会被读取到DS1302_Time数组中* @param  无* @retval 无*/void DS1302_ReadTime(void)
{unsigned char Temp;//BCD码转十进制后读取Temp=DS1302_ReadByte(DS1302_YEAR);DS1302_Time[0]=Temp/16*10+Temp%16;Temp=DS1302_ReadByte(DS1302_MONTH);DS1302_Time[1]=Temp/16*10+Temp%16;Temp=DS1302_ReadByte(DS1302_DATA);DS1302_Time[2]=Temp/16*10+Temp%16;Temp=DS1302_ReadByte(DS1302_HOUR);DS1302_Time[3]=Temp/16*10+Temp%16;Temp=DS1302_ReadByte(DS1302_MINUTE);DS1302_Time[4]=Temp/16*10+Temp%16;Temp=DS1302_ReadByte(DS1302_SECOND);DS1302_Time[5]=Temp/16*10+Temp%16;Temp=DS1302_ReadByte(DS1302_DAY);DS1302_Time[6]=Temp/16*10+Temp%16;
}

2）Proteus仿真

注意事项晶振

1. 进阶版可调时钟

#include <REGX52.H>
#include "LCD1602.h"
#include "Delay.h"
#include "Ds1302.h"
#include "Key.h"#include "Timer0.h"
unsigned char KeyNum,MODE=1,TimeSetSelect,TimeSetFlashFlag;void TimeShow()
{DS1302_ReadTime();//读取时间LCD_ShowNum(1,1,DS1302_Time[0],2);//显示年LCD_ShowNum(1,4,DS1302_Time[1],2);//显示月LCD_ShowNum(1,7,DS1302_Time[2],2);//显示日LCD_ShowNum(2,1,DS1302_Time[3],2);//显示时LCD_ShowNum(2,4,DS1302_Time[4],2);//显示分LCD_ShowNum(2,7,DS1302_Time[5],2);//显示秒
}
void TimeSet(void)//时间设置功能
{if(KeyNum==2)//按键2按下{TimeSetSelect++;//设置选择位加1TimeSetSelect%=6;//越界清零}if(KeyNum==3)//按键3按下{DS1302_Time[TimeSetSelect]++;//时间设置位数值加1if(DS1302_Time[0]>99){DS1302_Time[0]=0;}//年越界判断if(DS1302_Time[1]>12){DS1302_Time[1]=1;}//月越界判断if( DS1302_Time[1]==1 || DS1302_Time[1]==3 || DS1302_Time[1]==5 || DS1302_Time[1]==7 || DS1302_Time[1]==8 || DS1302_Time[1]==10 || DS1302_Time[1]==12)//日越界判断{if(DS1302_Time[2]>31){DS1302_Time[2]=1;}//大月}else if(DS1302_Time[1]==4 || DS1302_Time[1]==6 || DS1302_Time[1]==9 || DS1302_Time[1]==11){if(DS1302_Time[2]>30){DS1302_Time[2]=1;}//小月}else if(DS1302_Time[1]==2){if(DS1302_Time[0]%4==0){if(DS1302_Time[2]>29){DS1302_Time[2]=1;}//闰年2月}else{if(DS1302_Time[2]>28){DS1302_Time[2]=1;}//平年2月}}if(DS1302_Time[3]>23){DS1302_Time[3]=0;}//时越界判断if(DS1302_Time[4]>59){DS1302_Time[4]=0;}//分越界判断if(DS1302_Time[5]>59){DS1302_Time[5]=0;}//秒越界判断}if(KeyNum==4)//按键3按下{DS1302_Time[TimeSetSelect]--;//时间设置位数值减1if(DS1302_Time[0]<0){DS1302_Time[0]=99;}//年越界判断if(DS1302_Time[1]<1){DS1302_Time[1]=12;}//月越界判断if( DS1302_Time[1]==1 || DS1302_Time[1]==3 || DS1302_Time[1]==5 || DS1302_Time[1]==7 || DS1302_Time[1]==8 || DS1302_Time[1]==10 || DS1302_Time[1]==12)//日越界判断{if(DS1302_Time[2]<1){DS1302_Time[2]=31;}//大月if(DS1302_Time[2]>31){DS1302_Time[2]=1;}}else if(DS1302_Time[1]==4 || DS1302_Time[1]==6 || DS1302_Time[1]==9 || DS1302_Time[1]==11){if(DS1302_Time[2]<1){DS1302_Time[2]=30;}//小月if(DS1302_Time[2]>30){DS1302_Time[2]=1;}}else if(DS1302_Time[1]==2){if(DS1302_Time[0]%4==0){if(DS1302_Time[2]<1){DS1302_Time[2]=29;}//闰年2月if(DS1302_Time[2]>29){DS1302_Time[2]=1;}}else{if(DS1302_Time[2]<1){DS1302_Time[2]=28;}//平年2月if(DS1302_Time[2]>28){DS1302_Time[2]=1;}}}if(DS1302_Time[3]<0){DS1302_Time[3]=23;}//时越界判断if(DS1302_Time[4]<0){DS1302_Time[4]=59;}//分越界判断if(DS1302_Time[5]<0){DS1302_Time[5]=59;}//秒越界判断}//更新显示，根据TimeSetSelect和TimeSetFlashFlag判断可完成闪烁功能if(TimeSetSelect==0 && TimeSetFlashFlag==1){LCD_ShowString(1,1,"  ");}else {LCD_ShowNum(1,1,DS1302_Time[0],2);}if(TimeSetSelect==1 && TimeSetFlashFlag==1){LCD_ShowString(1,4,"  ");}else {LCD_ShowNum(1,4,DS1302_Time[1],2);}if(TimeSetSelect==2 && TimeSetFlashFlag==1){LCD_ShowString(1,7,"  ");}else {LCD_ShowNum(1,7,DS1302_Time[2],2);}if(TimeSetSelect==3 && TimeSetFlashFlag==1){LCD_ShowString(2,1,"  ");}else {LCD_ShowNum(2,1,DS1302_Time[3],2);}if(TimeSetSelect==4 && TimeSetFlashFlag==1){LCD_ShowString(2,4,"  ");}else {LCD_ShowNum(2,4,DS1302_Time[4],2);}if(TimeSetSelect==5 && TimeSetFlashFlag==1){LCD_ShowString(2,7,"  ");}else {LCD_ShowNum(2,7,DS1302_Time[5],2);}
}void main()
{LCD_Init();DS1302_Init();Timer0_Init();LCD_ShowString(1,1,"  -  -  ");LCD_ShowString(2,1,"  :  :  ");DS1302_SetTime();while(1){KeyNum=Key();if(KeyNum==1){if(MODE==0){MODE=1;}else if(MODE==1){MODE=0;DS1302_SetTime();}}switch(MODE){case 0:TimeShow();break;case 1:TimeSet();break;}}
}void Timer0_Routine() interrupt 1
{static unsigned int T0Count;TL0 = 0x18;        //设置定时初值TH0 = 0xFC;        //设置定时初值T0Count++;if(T0Count>=500)//每500ms进入一次{T0Count=0;TimeSetFlashFlag=!TimeSetFlashFlag;//闪烁标志位取反}
}