2021-08-10 11:02 PM
Hello!
I am trying to use the lptim1 to wake up my STM32wl55 from stop2 mode so I first check out the LPTIM_Timeout example. Unfortunately, it doesn't seem to work properly. The device does enter sleep mode, but it never wakes up.
I did some digging and found this similar post: https://community.st.com/s/question/0D53W00000q2p1WSAQ/does-st-confirm-the-lptimer-issue-with-stop-mode
I've tried adding __HAL_RCC_LPTIM1_CLK_SLEEP_ENABLE() ; to the example and I also checked that it uses LSI and not LSE, but the device still doesn't exit stop2 mode. Has anyone had a similar problem with the LPTIM_Timeout example? Thanks!
2021-09-28 05:50 AM
I had a similar problem, not with the example, but with a project of my own.
I made the change described here https://gist.github.com/jefftenney/02b313fe649a14b4c75237f925872d72#file-lptimtick-c-L291 (e.g. set bit 29 in EXTI-IMR1 for LPTIM1) and then the LPTIM1_IRQHandler was called during stop mode 2.
It would be nice to know if this is the way to do it, because it is not documented in the reference manual.