Why setting up RTC WKUP interrupt will generate HAL_RTCEx_SetWakeUpTimer_IT in init?

[Tuoman]

I want to enable RTC WKUP interrupt, so that I can use it later to wake the device up from sleep modes.

Nevertheless, CubeMX will also add HAL_RTCEx_SetWakeUpTimer_IT in init. I don't want to launch the timer in init! I only want to set it up for later use (setup interrupt handlers, NVIC enable).

1. Is this call 100% necessary? Why CubeMX generates it in init?
2. What does it mean if WakeUpCounter parameter to this call is 0?

[Nesrine.JLASSI]

Hi @Tuoman​ 

> Is this call 100% necessary? Why CubeMX generates it in init?

Yes STM32CubeMX calls this function when we activate the WakeUp, then go to the NVIC Settings table and Enable the RTC wake-up interrupt Through EXTI line 19.

When we generate code: we get this function

HAL_RTCEx_SetWakeUpTimer_IT

When we uncheck the RTC wake-up interrupt Through EXTI line 19

Then we go to the generated code: we get this function HAL_RTCEx_SetWakeUpTimer

> What does it mean if WakeUpCounter parameter to this call is 0?

0 is the default value, you can change it :

Best regards,

Nesrine

[Tuoman]

Hello, Nesrine. Unfortunately this did not answer my question at all. You answered how to setup WakeUp in CubeMX (I already know) and that I can change value from 0 (I already know)

My questions still remain;

1. Why is the HAL_RTCEx_SetWakeUpTimer_IT call necessary? I don't want to start the timer in init, I just want to set it up for later use. Why CubeMX automatically generates it in init? Is this CubeMX bug?
2. What does it mean if WakeUpCounter parameter to this call is 0? "0 is the default value" What does it do? Launch timer interrupt immediately? Nothing? Will it break something?