例子基本是照抄官方的 万年历算法也没深入研究 主要是大赛 都要求会用DS1302 若我用STM32来做 肯定不用那个片子了。

这个用的是 LSE (片外低速时钟)配合 掉电寄存器来确定是否配置时钟。本文引用地址：http://www.eepw.com.cn/article/201612/325211.htm

注释很全 话不多说了。

u8 TimeDisplay;

int main(void)

{

SystemInit();

stm32_Init ();//GPIO PA8 Init

USART_Configuration();//USART2 9600-8-N-1

NVIC_Configuration();//Enable the RTC Interrupt

RTC_Configuration();//RTC的启动

start_rct();//检测是否配置时钟

Time_Show();//不断地时钟串口输出

}

void LEDToggle(void)

{

GPIOA->ODR=GPIOA->ODR^GPIO_Pin_8 ;

}

RTC.C///

#include "stm32f10x.h"

#include //用到printf函数的串口的输出函数 注意勾选MicroLIB

u32 Time_Regulate(void);

void Time_Adjust(void);

void Time_Show(void);

void Time_Display(u32 TimeVar);

u32 USART_Scanf(u32 value);

extern u8 TimeDisplay;

void RTC_Configuration(void)

{

/* Enable PWR and BKP clocks */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

/* Allow access to BKP Domain */

PWR_BackupAccessCmd(ENABLE);

/* Reset Backup Domain */

//BKP_DeInit(); //记录0XA5A5 来确定是否重置时间

/* Enable LSE */

RCC_LSEConfig(RCC_LSE_ON);

/* Wait till LSE is ready */

while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)

{}

/* Select LSE as RTC Clock Source */

RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

/* Enable RTC Clock */

RCC_RTCCLKCmd(ENABLE);

/* Wait for RTC registers synchronization */

RTC_WaitForSynchro();

/* Wait until last write operation on RTC registers has finished */

RTC_WaitForLastTask();

/* Enable the RTC Second */

RTC_ITConfig(RTC_IT_SEC, ENABLE);

/* Wait until last write operation on RTC registers has finished */

RTC_WaitForLastTask();

/* Set RTC prescaler: set RTC period to 1sec */

RTC_SetPrescaler(32767); /* RTC period = RTCCLK/RTC_PR = (32.768 KHz)/(32767+1) */

/* Wait until last write operation on RTC registers has finished */

RTC_WaitForLastTask();

}

/*******************************************************************************

* Function Name : Time_Regulate

* Description : Returns the time entered by user, using Hyperterminal.

* Input : None

* Output : None

* Return : Current time RTC counter value

*******************************************************************************/

//u32 Month_Days[13] = {0,31,28,31,30, 31, 30, 31, 31, 30, 31, 30, 31};

u32 Month_Days_Accu_C[13] = {0,31,59,90,120,151,181,212,243,273,304,334,365};

u32 Month_Days_Accu_L[13] = {0,31,60,91,121,152,182,213,244,274,305,335,366};

#define SecsPerDay (3600*24)

u32 Time_Regulate(void)

{

#if 1

u32 Tmp_Year=0xFFFF, Tmp_Month=0xFF, Tmp_Date=0xFF;

u32 LeapY, ComY, TotSeconds, TotDays;

#endif

u32 Tmp_HH = 0xFF, Tmp_MM = 0xFF, Tmp_SS = 0xFF;

printf("\r\n==============Time Settings=====================================");

#if 1

printf("\r\n Please Set Year");

while(Tmp_Year == 0xFFFF)

{

/*32-bit counter at Second Unit--> 4*1024*1024(s) --> 49710(day) --> 136(year)*/

Tmp_Year = USART_Scanf(2136);

}

printf(": %d", Tmp_Year);

printf("\r\n Please Set Month");

while(Tmp_Month == 0xFF)

{

Tmp_Month = USART_Scanf(12);

}

printf(": %d", Tmp_Month);

printf("\r\n Please Set Date");

while(Tmp_Date == 0xFF)

{

Tmp_Date = USART_Scanf(31);

}

printf(": %d", Tmp_Date);

#endif

printf("\r\n Please Set Hours");

while(Tmp_HH == 0xFF)

{

Tmp_HH = USART_Scanf(23);

}

printf(": %d", Tmp_HH);

printf("\r\n Please Set Minutes");

while(Tmp_MM == 0xFF)

{

Tmp_MM = USART_Scanf(59);

}

printf(": %d", Tmp_MM);;

printf("\r\n Please Set Seconds");

while(Tmp_SS == 0xFF)

{

Tmp_SS = USART_Scanf(59);

}

printf(": %d", Tmp_SS);

#if 1

{

/* change Year-Month-Data-Hour-Minute-Seconds into X(Second) to set RTC->CNTR */

if(Tmp_Year==2000)

LeapY = 0;

else

LeapY = (Tmp_Year - 2000 -1)/4 +1;

ComY = (Tmp_Year - 2000)-(LeapY);

if (Tmp_Year%4)

//common year

TotDays = LeapY*366 + ComY*365 + Month_Days_Accu_C[Tmp_Month-1] + (Tmp_Date-1);

else

//leap year

TotDays = LeapY*366 + ComY*365 + Month_Days_Accu_L[Tmp_Month-1] + (Tmp_Date-1);

TotSeconds = TotDays*SecsPerDay + (Tmp_HH*3600 + Tmp_MM*60 + Tmp_SS);

}

#endif

/* Return the value to store in RTC counter register */

//return((Tmp_HH*3600 + Tmp_MM*60 + Tmp_SS));

return TotSeconds;

}

/*******************************************************************************

* Function Name : Time_Adjust

* Description : Adjusts time.

* Input : None

* Output : None

* Return : None

*******************************************************************************/

void Time_Adjust(void)

{

/* Wait until last write operation on RTC registers has finished */

RTC_WaitForLastTask();

/* Change the current time */

RTC_SetCounter(Time_Regulate());

/* Wait until last write operation on RTC registers has finished */

RTC_WaitForLastTask();

}

/*******************************************************************************

* Function Name : Time_Display

* Description : Displays the current time.

* Input : - TimeVar: RTC counter value.

* Output : None

* Return : None

*******************************************************************************/

#define SecsPerComYear 3153600//(365*3600*24)

#define SecsPerLeapYear 31622400//(366*3600*24)

#define SecsPerFourYear 126230400//((365*3600*24)*3+(366*3600*24))

#define SecsPerDay (3600*24)

s32 Year_Secs_Accu[5]={0,

31622400,

63158400,

94694400,

126230400};

s32 Month_Secs_Accu_C[13] = { 0,

2678400,

5097600,

7776000,

10368000,

13046400,

15638400,

18316800,

20995200,

23587200,

26265600,

28857600,

31536000};

s32 Month_Secs_Accu_L[13] = {0,

2678400,

5184000,

7862400,

10454400,

13132800,

15724800,

18403200,

21081600,

23673600,

26352000,

28944000,

31622400};

void Time_Display(u32 TimeVar)

{

#if 1

u32 TY = 0, TM = 1, TD = 0;

s32 Num4Y,NumY, OffSec, Off4Y = 0;

u32 i;

s32 NumDay; //OffDay;

#endif

u32 THH = 0, TMM = 0, TSS = 0;

#if 0

/* Compute hours */

THH = TimeVar/3600;

/* Compute minutes */

TMM = (TimeVar % 3600)/60;

/* Compute seconds */

TSS = (TimeVar % 3600)% 60;

#endif

#if 1

{

Num4Y = TimeVar/SecsPerFourYear;

OffSec = TimeVar%SecsPerFourYear;

i=1;

while(OffSec > Year_Secs_Accu[i++])

Off4Y++;

/* Numer of Complete Year */

NumY = Num4Y*4 + Off4Y;

/* 2000,2001,...~2000+NumY-1 complete year before, so this year is 2000+NumY*/

TY = 2000+NumY;

OffSec = OffSec - Year_Secs_Accu[i-2];

/* Month (TBD with OffSec)*/

i=0;

if(TY%4)

{// common year

while(OffSec > Month_Secs_Accu_C[i++]);

TM = i-1;

OffSec = OffSec - Month_Secs_Accu_C[i-2];

}

else

{// leap year

while(OffSec > Month_Secs_Accu_L[i++]);

TM = i-1;

OffSec = OffSec - Month_Secs_Accu_L[i-2];

}

/* Date (TBD with OffSec) */

NumDay = OffSec/SecsPerDay;

OffSec = OffSec%SecsPerDay;

TD = NumDay+1;

/* Compute hours */

THH = OffSec/3600;

/* Compute minutes */

TMM = (OffSec % 3600)/60;

/* Compute seconds */

TSS = (OffSec % 3600)% 60;

}

#endif

printf("Date: %0.4d-%0.2d-%0.2d Time: %0.2d:%0.2d:%0.2d\r",TY, TM, TD,THH, TMM, TSS);

}

/*******************************************************************************

* Function Name : Time_Show

* Description : Shows the current time (HH:MM:SS) on the Hyperterminal.

* Input : None

* Output : None

* Return : None

******************************************************************************/

void Time_Show(void)

{

printf("\n\r");

/* Infinite loop */

while (1)

{

/* If 1s has paased */

if(TimeDisplay == 1)

{

/* Display current time */

Time_Display(RTC_GetCounter());

TimeDisplay = 0;

}

}

}

/*******************************************************************************

* Function Name : USART_Scanf

* Description : Gets numeric values from the hyperterminal.

* Input : None

* Output : None

* Return : None

*******************************************************************************/

u32 USART_Scanf(u32 value)

{

u32 index = 0;

u32 tmp[4] = {0, 0};

u32 Num;

if (value==2136)

Num = 4;

else

Num = 2;

while(index < Num)

{

/* Loop until RXNE = 1 */

while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET)

{

}

tmp[index++] = (USART_ReceiveData(USART2));

if((tmp[index - 1] < 0x30) || (tmp[index - 1] > 0x39))

{

printf("\n\rPlease enter valid number between 0 and 9");

index--;

}

}

/* Calculate the Corresponding value */

if (value!=2136)

index = ((tmp[0] - 0x30) * 10) + (tmp[1] - 0x30);

else

index = ((tmp[0] - 0x30) * 1000) + ((tmp[1] - 0x30) * 100) + ((tmp[2] - 0x30) * 10) + (tmp[3] - 0x30);

/* Checks */

if(index > value)

{

printf("\n\rPlease enter valid number between 0 and %d", value);

return 0xFF;

}

return index;

}

void start_rct(void)

{

if(BKP_ReadBackupRegister(BKP_DR1) != 0xA5A5)

{

/* Backup data register value is not correct or not yet programmed (when

the first time the program is executed) */

printf("\r\n\n RTC not yet configured....");

/* RTC Configuration */

RTC_Configuration();

printf("\r\n RTC configured....");

/* Adjust time by values entred by the user on the hyperterminal */

Time_Adjust();

BKP_WriteBackupRegister(BKP_DR1, 0xA5A5);

}

else

{

/* Check if the Power On Reset flag is set */

if(RCC_GetFlagStatus(RCC_FLAG_PORRST) != RESET)

{

printf("\r\n\n Power On Reset occurred....");

}

/* Check if the Pin Reset flag is set */

else if(RCC_GetFlagStatus(RCC_FLAG_PINRST) != RESET)

{

printf("\r\n\n External Reset occurred....");

}

printf("\r\n No need to configure RTC....");

/*一下都是可以省略的 RTC_Configuration 已有启用 RTC_IT_SEC */

/* Wait for RTC registers synchronization */

RTC_WaitForSynchro();

/* Enable the RTC Second */

RTC_ITConfig(RTC_IT_SEC, ENABLE);

/* Wait until last write operation on RTC registers has finished */

RTC_WaitForLastTask();

}

}

其中这个函数决定了 printf 函数的输出目标 一定要有的。

int fputc(int ch)

{

USART_SendData(USART2, (u8) ch);

while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);

return ch;

}

秒中断；

/******************************************************************************/

/* STM32F10x Peripherals Interrupt Handlers */

/******************************************************************************/

/**

* @brief This function handles RTC global interrupt request.

* @param None

* @retval None

*/

extern u8 TimeDisplay;

void LEDToggle(void);

void RTC_IRQHandler(void)

{

if (RTC_GetITStatus(RTC_IT_SEC) != RESET)

{

/* Clear the RTC Second interrupt */

RTC_ClearITPendingBit(RTC_IT_SEC);

/* Toggle LED1 闪灯*/

LEDToggle();

/* Enable time update */

TimeDisplay = 1;

}

}

不要使用串口助手 推荐使用超级终端。