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Visitor II
August 12, 2022
Solved

Wake up vs Alert in RTC

  • August 12, 2022
  • 6 replies
  • 3347 views

Hi, could someone explain me what is the difference between wake up and alert in RTC?

For example the UM1749 provides information about RTC Alarm functions (section 39.2.8) and wake-up functions (section 40.2.2)

When should I use the wake-up and when the alert?

    This topic has been closed for replies.
    Best answer by Peter BENSCH
    Well, you could use either wakeup or alarm. But an alarm has to be set again after expiring.
    Good luck!
    /Peter

    6 replies

    Technical Moderator
    August 12, 2022

    Wakeup is intended for uniformly repeating events (e.g. wakeup every 10 seconds), while the alarm can be compared to the wake-up function of an alarm clock and is usually only triggered once.

    Does it answer your question?

    Regards

    /Peter

    Visitor II
    August 13, 2022

    Thank you a lot @Peter BENSCH​ for your response. In my application, I want the MCU to wake-up once per day at 12:00PM. So, should I use the wakeup instead of the alarm?

    Graduate II
    August 12, 2022

    The reference manual for your MCU explains it clearly.

    Technical Moderator
    August 13, 2022
    Well, you could use either wakeup or alarm. But an alarm has to be set again after expiring.
    Good luck!
    /Peter
    Graduate II
    March 5, 2024

    If you use mask, no need to set again your alarm, or I maybe miss something ?

    Visitor II
    August 16, 2022

    Thank you very much @Peter BENSCH​ 

    Technical Moderator
    August 16, 2022

    You're welcome.

    If the problem is resolved, please mark this thread as answered by selecting Select as best under your preferred answer. This will help other users find that answer faster.

    Regards

    /Peter

    Graduate II
    March 5, 2024

    As I am wondering same question, I'll add some informations about this subject (feel free to correct me as I am new to these subjects) :

    - I think that if you use mask, you dont have to reconfigure your alarm. The callback function of your alarm can be called forever, with a few settings

    - Alarm seems a bit easier to use (as you only have to provide a date/time alarm, and provide a mask if you need it). For WakeUp Timer, you should chose the clock you want to use, and do simple math with frequency/prescaler of your clock. Otherwise, if you change clock frequency, this will probably change your loop.

     

    For my case, I only need to go in sleep mode, and exit that sleep mode to measure data only once per minute. I already did the loop with alarm, work well, but I discovered WakeUp Timer. 

    Do you have any advice on what to use ? Do you know others differences that we listed here ?

    Graduate II
    March 6, 2024

    Maybe someone have more informations to share ?