No serial output after first wake from deepsleep

miroslavpetrov commented 5 months ago

Describe the bug Using the unmodified example AlarmTimedWakeup.ino from the library and Seeed Lora-E5 Mini board, after the first wake up from deepsleep there is no output on the serial console.

To Reproduce Upload AlarmTimedWakeup example to the board.

Expected behavior I expect the serial port to continue working after wake up

Desktop (please complete the following information):

OS: Mac OS Sonoma 14.5
Arduino IDE version: 2.3.2
STM32 core version: 2.8.0
Library version: 1.2.5
Tools menu settings if not the default: Core logs enabled, Optimize: smallest, Runtime Newlib nano, UART: Enabled(generic serial), Board part number - Lora-E5 mini
Upload method: manual export compiled binary and drag and drop to STLink drive

Hardware (please complete the following information):

Board Name: Seeed Wio-E5 Mini based on STM32wle5jc
Hardware Revision: v1.0

miroslavpetrov commented 4 months ago

@fpistm any ideas?

fpistm commented 4 months ago

No. I will check when I will have some time.

fpistm commented 3 months ago

Hi @miroslavpetrov I've reproduced and try to debug deeply but hard with this series as debug with low power mode is a nightmare (several issue document in the errata sheet). In the case of STM32WL, the deepsleep rely on STOP 2 mode and so it requires to properly init the Serial after the deepsleep.

stm32duino / STM32LowPower

No serial output after first wake from deepsleep #110