WakeUp from STOPMode at arbitrary time

curiae · ‎2024-12-01

Hello,

Now I'm developing on STM32L052T8Y6TR and thinking to occur every 20msec WakeUp from systick interrupt.

More concretely, after Entering Stop Mode (by HAL_PWR_EnterSTOPMode),

I want to start wake-up at arbitrary time. in the SysTick_Callback.

I know HAL_RTCEx_SetWakeUpTimer_IT as regular wake-up function, I'd know how to start wake-up immediately.

Please tell me how to realize it.

Thanks,

Sarra.S · ‎2024-12-03

Hello @curiae,

Could you please clarify whether you want the wake-up event to occur periodically every 20 milliseconds, or if you want it to occur non-periodically, similar to using an external interrupt (EXTI)?

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Andrew Neil · ‎2024-12-03

@curiae wrote:
occur every 20msec WakeUp from systick interrupt.

You can stop that with HAL_SuspendTick

@curiae wrote:
I want to start wake-up at arbitrary time. in the SysTick_Callback.

Why would you do that in the SysTick callback?

Why not just use the HAL_RTCEx_SetWakeUpTimer_IT ?

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.

Andrew Neil · ‎2024-12-18

@Andrew Neil wrote:
You can stop that with HAL_SuspendTick

See: https://community.st.com/t5/stm32-mcus-boards-and-hardware/how-to-stop-systick-during-rtc-power-stop-mode/m-p/731819/highlight/true#M21968

@curiae has that resolved your issue?

If so, please mark the solution:

https://community.st.com/t5/community-guidelines/help-others-to-solve-their-issues/ta-p/575256

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.