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HCohe.1
HCohe.1
Associate III
January 20, 2022
Solved

HW_Timerserver Hangs on STM32WB w/ BLE

  • January 20, 2022
  • 9 replies
  • 6956 views

Any program that I generate using STM32CubeIDE for the STM32WB with BLE enabled hangs until I comment out the following line. What needs to change in the initialization sequence?

  /**

   * We should never end up in this case

   * However, if due to any bug in the timer server this is the case, the mistake may not impact the user.

   * We could just clean the interrupt flag and get out from this unexpected interrupt

   */

  while(__HAL_RTC_WAKEUPTIMER_GET_FLAG(phrtc, RTC_FLAG_WUTWF) == RESET);

This topic has been closed for replies.
Best answer by Remy ISSALYS

Hello,

Indeed, if the Hardware Time Server (HW_TS) is not initialized (via MX_APPE_Init()) quickly enough after the RTC initialization (via MX_RTC_Init()), the code might get stuck in an infinite loop in the HW_TS_RTC_Wakeup_Handler() function.

To avoid this problem there is 2 solutions:

  • Solution 1:

Remove the following code in MX_RTC_Init function in main.c file:

 /** Enable the WakeUp

 */

 if (HAL_RTCEx_SetWakeUpTimer(&hrtc, 0, RTC_WAKEUPCLOCK_RTCCLK_DIV16) != HAL_OK)

 {

  Error_Handler();

 }

You will have to remove it after every new code generation with STM32CubeMX.

  • Solution 2:

To avoid to do modification every new code generation with STM32CubeMX.

> Change Wake Up Counter value:

If you used CubeMX, in RTC configuration change default value by 0xFFFF:

0693W00000KaH2QQAV.pngOr in MX_RTC_Init function in main.c, change the second parameter of this function by replace 0 value:

HAL_RTCEx_SetWakeUpTimer(&hrtc, 0, RTC_WAKEUPCLOCK_RTCCLK_DIV16)

by 0xFFFF:

HAL_RTCEx_SetWakeUpTimer(&hrtc, 0xFFFF, RTC_WAKEUPCLOCK_RTCCLK_DIV16)

> Add the following line in RTC_Init 2 User Code Section (in MX_RTC_Init function in main.c) :

 __HAL_RTC_WAKEUPTIMER_DISABLE(&hrtc);

Best Regards,

9 replies

Remy ISSALYS
Remy ISSALYSBest answer
ST Technical Moderator
February 23, 2022

Hello,

Indeed, if the Hardware Time Server (HW_TS) is not initialized (via MX_APPE_Init()) quickly enough after the RTC initialization (via MX_RTC_Init()), the code might get stuck in an infinite loop in the HW_TS_RTC_Wakeup_Handler() function.

To avoid this problem there is 2 solutions:

  • Solution 1:

Remove the following code in MX_RTC_Init function in main.c file:

 /** Enable the WakeUp

 */

 if (HAL_RTCEx_SetWakeUpTimer(&hrtc, 0, RTC_WAKEUPCLOCK_RTCCLK_DIV16) != HAL_OK)

 {

  Error_Handler();

 }

You will have to remove it after every new code generation with STM32CubeMX.

  • Solution 2:

To avoid to do modification every new code generation with STM32CubeMX.

> Change Wake Up Counter value:

If you used CubeMX, in RTC configuration change default value by 0xFFFF:

0693W00000KaH2QQAV.pngOr in MX_RTC_Init function in main.c, change the second parameter of this function by replace 0 value:

HAL_RTCEx_SetWakeUpTimer(&hrtc, 0, RTC_WAKEUPCLOCK_RTCCLK_DIV16)

by 0xFFFF:

HAL_RTCEx_SetWakeUpTimer(&hrtc, 0xFFFF, RTC_WAKEUPCLOCK_RTCCLK_DIV16)

> Add the following line in RTC_Init 2 User Code Section (in MX_RTC_Init function in main.c) :

 __HAL_RTC_WAKEUPTIMER_DISABLE(&hrtc);

Best Regards,

HCohe.1
HCohe.1Author
Associate III
February 23, 2022

How will the Hardware Timer Server continue to work after I apply either of these two solutions? The first solution removes the function that enables the wake-up timer. The second one disables it.

Remy ISSALYS
Remy ISSALYS
ST Technical Moderator
February 23, 2022

Hello,

Wake Up Timer is started inside Hardware Timer Server initialization see HW_TS_Init() function.

Regards

dungeonlords789
dungeonlords789
Associate III
February 23, 2022

I suggest ST to add link to this forum thread inside code's comment

 * Wait for the flag to be back to 0 when the wakeup timer is enabled

    */

   while(__HAL_RTC_WAKEUPTIMER_GET_FLAG(phrtc, RTC_FLAG_WUTWF) == SET);

like

 * Wait for the flag to be back to 0 when the wakeup timer is enabled

    See also https://community.st.com/s/question/0D53W00001K2koYSAR/hwtimerserver-hangs-on-stm32wb-w-ble?t=1645623930307 or https://github.com/STMicroelectronics/STM32CubeWB/issues/52 */

   while(__HAL_RTC_WAKEUPTIMER_GET_FLAG(phrtc, RTC_FLAG_WUTWF) == SET);

Remy ISSALYS
Remy ISSALYS
ST Technical Moderator
February 24, 2022

Hello,

Thanks for your proposal, we study internally the best way to correct this problem.

Regards

EKoss.1
EKoss.1
Associate
May 4, 2022

Hello,

I don't know if this issue is already solved in the later versions of the FW. I have something that seems related to this (not sure if it is). I have setup a project using the Custom P2P server settings. When I add the HW_time server to it the code hangs. I have one project in which the code gets into the infinite loop (when debuggin) and I have setup a project with minimalistic use of these functions which gets stuck in the HardFaultHandler (after subscriping to the BLE notification characteristic (which starts the HW_TS).

The strange thing about this is that I had the minimalistic project running without issues until I've re-generated the CubeMX project (without making any changes).

I think I should open a new issue for this but wanted to share this here as well.

I have made a github repo which can be viewed what I've done:

https://github.com/E-Emiel/TimeServerV1

Regards

dungeonlords789
dungeonlords789
Associate III
May 26, 2022

@Remy ISSALYS​ any news?

HCohe.1
HCohe.1Author
Associate III
May 26, 2022

Yes @Remy ISSALYS​ , I resolved the problem using just the second part of Solution 2 above - to edit MX_RTC_Init() and disable the wakeup timer in the user code section.

 /* USER CODE BEGIN RTC_Init 2 */
 HAL_RTCEx_DeactivateWakeUpTimer(&hrtc);	// Now disable it to prevent interrupts before HW_Timerserver is ready for them.
 /* USER CODE END RTC_Init 2 */

We can close this issue.

Ugilten
Ugilten
Associate III
October 11, 2022

I just spent the last two days chasing this daemon.

I found the MX_RTC_Init() function was followed by 5 other init functions (generated by CubeMX) before the MX_APPE_Init() function.

This would cause too much time to pass between the two function calls and causes a hard fault because the phrtc pointer would be empty in HW_TS_RTC_Wakeup_Handler().

I decided to tell CubeMX to not generate function calls for these two modules. This allows me to call them inside the USER CODE BEGIN 2 area and keep them close together.

I don't know if there are any disadvantages to this approach, but it seems to work fine.

Remy ISSALYS
Remy ISSALYS
ST Technical Moderator
October 11, 2022

Hello,

This issue will be fixed in next STM32CubeWB release (v1.15.0) available soon.

Best Regards

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