Setting up the LSE clock in STM32L431RCTX

[Thenuk__a]

I have setup the RTC LSI on the board and got the serial print date and time. and now i wanted to get the RTC LSE clock and serial print clock values. i configured the clock configuration in LSE by following the same steps as i did in LSI, but it didn't work. It prints like this.

[Andrew Neil]

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@Thenuk__a wrote:

 it didn't work. 

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More details needed!

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228

[TDK]

Is this custom hardware? Perhaps the LSE design is insufficient. Debug your code and find out if the LSE gets successfully started.

[Thenuk__a]

First, i will initialize the time and then the clock is set up and the count continues. It will show up on the serial monitor of the CubeIDE. This one I have done this by enabling LSI on the clock configuration. Now I wanted to do it by enabling LSE. The reason I can't use LSI is because there is a time shift in the LSI and I hope that there is no time shift it LSE. 

Here by I have attached how I did in LSI and I wanted to do similarly in LSE

[Thenuk__a]

Yes it's custom. can i know what u mean by LSE design insufficient ? 

[TDK]

Incorrect load caps. Traces too long. That sort of thing.

Perhaps take a look at

cd00221665-oscillator-design-guide-for-stm8af-al-s-stm32-mcus-and-mpus-stmicroelectronics.pdf

[Andrew Neil]

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@Thenuk__a wrote:

Yes it's custom.  

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So please post the schematic - per the posting tips:

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228

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@Thenuk__a wrote:

 what u mean by LSE design insufficient ? 

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Basically, the design is poor or wrong - the oscillator doesn't work.

Did you follow the design guidelines in the datasheet and the various Application Notes; eg,

AN2867 Guidelines for oscillator design on STM8AF/AL/S and STM32 MCUs/MPUs

AN4555 Getting started with STM32L4 Series and STM32L4+ Series hardware development

AN4759 Introduction to using the hardware real-time clock (RTC) and the tamper management unit (TAMP) with STM32 MCUs