Skip to main content
Associate
June 16, 2025
Question

Nulceo WB55 Example not waking up from stop mode from LPUART

  • June 16, 2025
  • 2 replies
  • 472 views

I have referred to the Example project "LPUART_WakeUpFromStop_Init". Configured an LP-UART in interrupt mode with a baud rate of 9600, Stop bit 1, Parity None, and enabled the HSI clock source for it. When the device enters the stop mode, try to send a character to wake it. But it is not all waking up.

 

We need to try this on Nulceo WB55 evaluation board. Once it works, we need to use it on our product which uses the uC STM32WB55VGQ.

Manoj1_1-1750084831484.png

2 replies

Andrew Neil
Super User
June 16, 2025

@Manoj1 wrote:

We need to (sic?)  try this on Nulceo WB55 


Do you mean you are trying this on a Nucleo WB55 ?

 

Are you certain that it actually does enter STOP mode?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
Manoj1Author
Associate
June 17, 2025

Answer to

  1. Yes, I am trying this on the Nuleo WB55 evaluation board.
  2.  Yes, it entered the stop mode.

 

 

STTwo-32
Technical Moderator
June 16, 2025

Hello @Manoj1 

Have you tested the example "LPUART_WakeUpFromStop_Init" as it is, if it is working fine, you shoudl check the impact of your changes on the code. Also, you may check if the Code enter stop mode and if HSI16 oscillator is forced ON even in Stop mode.

Best Regards.

STTwo-32

Manoj1Author
Associate
June 17, 2025

Please find the attachment, which has the project I have configured by referring to the example project. I did the same on the STM32 WB55. If there are any issues with my project, let me know.

STTwo-32
Technical Moderator
July 1, 2025

Have you tested the original ST Example. If it is working fine, please try to make a step by step changing so you can discover the error source.

Best Regards.

STTwo-32