RTC, how to configure periodic wake up time of 24h

[chai2145]

Hi, I'm using STM32L0 series MCU to configure the RTC to wake up after 24 hour during sleep/standby mode. Understand that we need to configure the Wake up clock to use 1Hz with 1 bit wake up counter added so that it can have the wake up time from 18h to ~36h.

Anyone know what number of wake up counter I have to set in order to have 24 hours wake up time? The wake up counter is 16 bit with max value of 65535.

if configure the Wake up clock to use 1Hz with 1 bit wake up counter added (RTC_WAKEUPCLOCK_CK_SPRE_17BITS), we can set the wake up time range from < 1hour up to 36h  or from 18h up to 36h?

[freedomcain]

thanks Pedro

[freedomcain]

thanks。

[PGump.1]

Hi,

What is the clock source and frequency for the RTC?

Kind regards
Pedro

[PGump.1]

Hi,

Do you have an Alarm set?

Kind regards
Pedro