Board resets systematically from standby mode

[nogema]

Hello,

I would like to reach the lowest consumption as possible. I am programming an end node which sends data through TTN. My project is based on the LoRaWAN End Node example with the LoRaWAN middleware.

My fimrware works like that :

• at boot, the board join to TTN
• after joined, the board turns in low power mode
• if the button on the board is pressed, the board wakes up and sends some datas to TTN
• after received the acknoledge, the board turns in low power mode

The example PWR_STANDBY works without any problem, I reach a consumption of 1.1 µA. I copied the code that configures and turns the board in standby mode into my firmware but at each boot, after reached the function HAL_PWR_EnterSTANDBYMode(), the board resets automatically.

Do you have any idea what I did wrong or miss in my firmware ? I can add the source code if needed.

I am using a custom board with the LoRa E5 STM32WL5EJC module embedded and the STM32WL package.

Thanks you in advance

Regards

[Tesla DeLorean]

STANDBY exits via RESET

Check you don't have any other circuits which will POR when the supply goes away.

[nogema]

I don't have any other circuits and supply on my board

[Piranha]

https://community.st.com/s/question/0D53W00001bnh8dSAA/how-to-enter-standby-or-shutdown-mode-on-stm32

[nogema]

Thanks you Piranha, it works !

I copied your code, I changed the wakeup pin because I only use the wakeup pin 1 (A0) and I added some #define because I don't have "PWR_CR1_LPMS_STANDBY". I found the definitions from this post :

https://gist.github.com/jefftenney/02b313fe649a14b4c75237f925872d72?permalink_comment_id=3758206#gistcomment-3758206

In standby mode, the consumption is 1.08 µA and in shutdown mode, 0.39 µA.

But after leaving the standby mode the first time, the consumption reaches 0.5 mA. I must turn off then turn on the supply to have again 1.08 µA. Is there a flag to clear after reset to have the 1.08 µA ?

Regards

[Piranha]

You don't have to search the register values on the internet - they are documented in the reference manual.

Seems like the issue 3a is still not solved for you. Did you define the NDEBUG for a non-debug build and tested that build?

[Jorgie]

Is there a generic solution to this for all of the STM32 Family?

I am currently trying to enter SHUTDOWN Mode in an STM32U083 and the processor keeps resetting and starting to run the code from the beginning again.

I'm calling:

HAL_PWR_EnterSHUTDOWNMode

I have added:

PWR->SCR = PWR_SCR_CWUF; // Clear wakeup flags

To the  void HAL_PWR_EnterSHUTDOWNMode(void) function but it is still resetting.