External clock (LSE) is not working in RTC Feature

[NAVEENNAMANI]

Hello @ ST Forum.

RTC is not Working with external clock. we tested with LSI and it is working fine.

Error we found that is HAL_Timeout:

PFA "LSE Firmware" for Firmware Error found at

Hardware Configurations

A. PFA "LSE Layout" for below information. 

1 & 2 are the 0Ω resistors

3 & 4 are the Load Capacitors

5 is the Crystal oscillator 

B . PFA "LSE Schematic" for circuit Reference and Oscillator part-number.

[Sarra.S]

Hello @NAVEENNAMANI, welcome to ST Community, 

You can refer to this application note: Guidelines for oscillator design on STM328F/AL/S and STM32 MCUs/MPUs 

[waclawek.jan]

As @Sarra.S said above, start with reading the application note.

Pay extra attention to the ground arrangement/layout. There's an example in the appnote. The ground from the capacitors must go the shortest possible way to the ground pin closest to the oscillator pins, and must not be shared by any other circuitry. You may try to improvize this on your existing board by cutting the ground path and routing it to the closest ground pin using a very short wire.

JW

[TDK]

Also take a look at this article:

How to select a compatible crystal and load capaci... - STMicroelectronics Community