I am using an STM32L053C8 and I am trying to set up an RTC wakeup event, and while I am successful, I can only do it to a max time which is a couple of seconds. I need to put it in standby and wake up days later. At the moment I am using the low speed internal 40KHz as the RTC clock, eventually i will get a 32.768 crystal.
According to Carmine Noviello-Mastering STM32 i should be able to set the wakeup delay for a pretty long time. And while I do know it says using an external clock, using the internal one of a few Khz should still be able to provide a fairly decent delay for testing purposes. I just cannot figure it out. When I chose the 1Hz setting for the wake up clock, that only means it will use the RTC clock (40Khz)/(Asynch_prediv +1 x Synch_prediv+1) = new wake up clock frequency.It calls it 1Hz because it assumes you have set up the calendar to have a 1Hz frequency. Its too bad I can use the calendar as a wake up event.