stm32f103 RTC periodic standby wake-up (I)

I have been working on a low-power device for several days, but the program has been stuck in one place (see the picture below). Today I finally found out where the problem lies. I will summarize the problems of standby wakeup (only for the problems I encountered, the other parts are available on the Internet, based on stm32f103)

1. Solve the problems I encountered

       My RTC initialization part has a "judgment of whether the RTC flag stored in the backup register has been configured". If it has been configured, it will enter the else part, but this else part does not have the configuration statements "to enable the power clock, enable the backup clock, and cancel the write protection of the backup area". After the standby wakes up, the program will execute from the main function and will execute to the else part. Because there are no such configuration statements, the alarm clock will not be assigned again and it will be stuck there. (Those configuration statements are in the clock_ini function, with comments)

2. Whether to add extiline17 event in standby mode

If the service program of the alarm interrupt is placed in void RTC_IRQHandler(void) for processing, the extiline17 event is not required to wake up (tested). If the service program of the alarm interrupt is placed in void RTCAlarm_IRQHandler(void) for processing, the extiline17 event is required

3. RTCAlarm_IRQn and RTC_IRQn priority

I saw on the Internet that the priority of RTCAlarm_IRQn should be set higher than that of RTC_IRQn, but if the service program of the alarm interrupt is placed in void RTC_IRQHandler(void), it is not necessary to set it this way. If the service program of the alarm interrupt is placed in void RTCAlarm_IRQHandler(void), it is necessary to set the priority. It is best to solve the priority problem according to the situation.

4. Here are some of my codes

1. 
   

2. void Clock_ini(void)

3. {

4. if(BKP_ReadBackupRegister(BKP_DR1) != 0xA5A5) //Judge whether the RTC flag stored in the backup register has been configured

5. {

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

7. RTC_Configuration(); //RTC initialization

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

9. Time_Adjust(); //Set RTC clock parameters

10. BKP_WriteBackupRegister(BKP_DR1, 0xA5A5); //After RTC is set, write the configured flag to the backup data register

11. }

12. else

13. {

14. if(RCC_GetFlagStatus(RCC_FLAG_PORRST) != RESET) //Check whether power is off and restarted

15. {

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

17. }

18. else if(RCC_GetFlagStatus(RCC_FLAG_PINRST) != RESET) //Check if reset is set

19. {

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

21. }

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

23. /***Newly added, test, after waking up from standby, the program does not go through the above if part, so there are no these three steps (two statements), so the program will get stuck, so add it, sure enough***/

24. RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

25. /* Allow access to BKP area */

26. PWR_BackupAccessCmd(ENABLE);

27.  

28. RTC_WaitForSynchro(); //Wait for the RTC register to be synchronized

29. RTC_ITConfig(RTC_IT_SEC, ENABLE); //Enable second interrupt

30. RTC_WaitForLastTask();

31. RTC_ITConfig(RTC_IT_ALR, ENABLE); //naozhong

32. RTC_WaitForLastTask(); //Wait for writing to complete

33. }

34. RCC_ClearFlag(); //Clear reset flag

1. void NVIC_Configuration(void)

2. {

3. NVIC_InitTypeDef NVIC_InitStructure;

4. EXTI_InitTypeDef EXTI_InitStructure;

5.  

6. NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

7.  

8. /* Enable the RTC Interrupt */

9. NVIC_InitStructure.NVIC_IRQChannel = RTC_IRQn; //Configure external interrupt source (second interrupt)

10. NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

11. NVIC_InitStructure.NVIC_IRQChannelSubPriority = 7;

12. NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

13. NVIC_Init(&NVIC_InitStructure);

14.  

15. /* Enable the RTC Alarm Interrupt */

16. NVIC_InitStructure.NVIC_IRQChannel = RTCAlarm_IRQn; //Configure external interrupt source (alarm interrupt)

17. NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

18. NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;

19. NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

20. NVIC_Init(&NVIC_InitStructure);

21.  

22. //The alarm interrupt is connected to the 17th line external interrupt

23. EXTI_ClearITPendingBit(EXTI_Line17);

24. EXTI_InitStructure.EXTI_Line = EXTI_Line17;

25. EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

26. EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;

27. EXTI_InitStructure.EXTI_LineCmd = ENABLE;

28. EXTI_Init(&EXTI_InitStructure);

29. }

1. void RTC_Configuration(void)

2. {

3. /* Enable PWR and BKP clocks */

4. RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

5. /* Allow access to BKP area */

6. PWR_BackupAccessCmd(ENABLE);

7. /* Reset BKP */

8. BKP_DeInit();

9. #ifdef RTCClockSource_LSI

10. /* Enable internal RTC clock */

11. RCC_LSICmd(ENABLE);

12. /* Wait for the RTC internal clock to be ready*/

13. while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)

14. {

15. }

16. /* Select RTC internal clock as RTC clock */

17. RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);

18. #elif defined RTCClockSource_LSE

19. /* Enable RTC external clock */

20. RCC_LSEConfig(RCC_LSE_ON);

21. /* Wait for RTC external clock to be ready*/

22. while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)

23. {

24. }

25. /* Select RTC external clock as RTC clock */

26. RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

27. #endif

28. /* Enable RTC clock */

29. RCC_RTCCLKCmd(ENABLE);

30.  

31.  

32. #ifdef RTCClockOutput_Enable

33. /* Disable the Tamper Pin */

34. BKP_TamperPinCmd(DISABLE); /* To output RTCCLK/64 on Tamper pin, the tamper

35. functionality must be disabled */

36.  

37. /* Enable RTC clock output on TAMPER pin */

38. BKP_RTCCalibrationClockOutputCmd(ENABLE);

39. #endif

40.  

41. /* Wait for RTC register synchronization */

42. RTC_WaitForSynchro();

43.  

44. /* Wait for writing RTC register to complete */

45. RTC_WaitForLastTask();

46.  

47. /* Enable RTC naozhong interrupt */

48. RTC_ITConfig(RTC_IT_ALR, ENABLE);

49.  

50. /* Wait for writing RTC register to complete */

51. RTC_WaitForLastTask();

52.  

53. /* Enable RTC seconds interrupt */

54. RTC_ITConfig(RTC_IT_SEC, ENABLE);

55.  

56. /* Wait for writing RTC register to complete */

57. RTC_WaitForLastTask();

58.  

59. /* Set RTC prescaler */

60. #ifdef RTCClockSource_LSI

61. RTC_SetPrescaler(31999); /* RTC period = RTCCLK/RTC_PR = (32.000 KHz)/(31999+1) */

62. #elif defined RTCClockSource_LSE

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

64. #endif

65.  

66. /* Wait for writing RTC register to complete */

67. RTC_WaitForLastTask();

68. }

1. void RTCAlarm_IRQHandler(void)

2. {

3. RTC_WaitForSynchro();

4. if(RTC_GetITStatus(RTC_IT_ALR) != RESET)

5. {

6. //printf("mmmmmm");

7. EXTI_ClearITPendingBit(EXTI_Line17);

8. RTC_WaitForLastTask();

9. if(PWR_GetFlagStatus(PWR_FLAG_WU) != RESET)

10. {

11. // Clear the wake-up flag

12. PWR_ClearFlag(PWR_FLAG_WU);

13. RTC_WaitForLastTask();

14. }

15. RTC_ClearITPendingBit(RTC_IT_ALR);

16. RTC_WaitForLastTask();

17. printf("\nIt will wake up after %ds\n",standbytime);

18. RTC_Enter_StandbyMode(standbytime); //Wake up after standbytime seconds

19. }

20. }

1. void RTC_Enter_StandbyMode(u32 s)

2. {

3. RTC_WaitForLastTask();

4. RTC_SetAlarm(RTC_GetCounter()+s);

5. RTC_WaitForLastTask();

6. // Enter standby mode, at this time all 1.8V domain clocks are turned off, HIS and HSE oscillators are turned off, and voltage regulators are turned off.

7. // Only WKUP pin rising edge, RTC warning event, NRST pin external reset, IWDG reset.

8. /* Request to enter STANDBY mode (Wake Up flag is cleared in PWR_EnterSTANDBYMode function) */

9. PWR_EnterSTANDBYMode();

10. }

5. In the next few days, I will study the shutdown mode and power consumption issues.