Stop mode and clock configuration at wake up

[Aurélien f]

Posted on December 28, 2017 at 07:42

Hello,

I'm facing an issue i cannot figure out. I'm currently working on a stm32l073 and using the following RTOS : RIOT-OS. When i wake up from stop mode, UART seems to be desynchronized because wrong characters are displayed. 

I have noticed that when i'm decreasing system clock, AHB clock and ABP clock all is working fine. Am i doing something wrong or do i need to reconfigure clock in the interrupt that is waking up the CPU from stop mode (this a RTC interrupt) ? 

If you have any ideas about this issue, feel free to share your thoughts

Best regards,

Aur�lien

#stm32 #stop-mode #stm32l073

[Enrico Poli]

Posted on January 04, 2018 at 14:02

I think this is a question for the

https://community.st.com/community/stm32-community/stm32-forum

[buff thokoa]

Posted on May 02, 2018 at 19:27

Hi 

Aurélien,

I am also experiencing the same thing...

Did you ever have any luck with a solution??

[Aurélien f]

Posted on May 02, 2018 at 21:35

Hi,

Now, just after the wake up, i reconfigure the clock. Actually, this is done by the RTOS. I'm using RIOT-OS which is quite new but well done. 

Regards,

Aurélien

[buff thokoa]

Posted on May 02, 2018 at 21:43

Hi,

I have not been as lucky as you I'm afraid.

I'm using MXCUBE and FREERTOS. The steps I am following are:

Before STOP Mode I do some hardware configuration, deinit the UART and start the RTC wake up on interrupt.

When that is done I reinit the UART. I am expecting to see a message OK come back from the UART but nothing happens.