I want to use RTC to wake-up from sleep but after system go to sleep mode interrupt of RTC not triggered. I saw examples where WDT triggered each second but it not good decision because power consumption. I need system sleep to long time (days).
How to make it work ?
RTC is pure software, so it cannot wake you up from sleep mode. 18hrs is the maximum WDT interval, but I always would suggest to keep it shorter (1s) and after some internal work go back to (deep) sleep again. The time the system is powered is comparably slow. So the averaged impact on power consumption is only a bit.
Looks like all "Low Power" is bullshit because using WDT not give economy because each sec tick and very not comfortable as RTC.
RTC I can`t use because can`t wake-up. And BTW I can`t put BLE to sleep mode because "In process of entering in BLESS Deep Sleep Mode, BLE Stack puts CPU in Sleep Mode to save power "
BLE stack will put CPU into sleep before entering BLESS deepsleep, you are right. But, BLESS will wake up CPU in the next connection interval. If you want to advertise some data and then put the system into sleep for a longer time (and doesn't want any frequent wakeup due to BLESS) you may stop BLE using CyBLE_Stop() after advertising the data. You can now put the system in sleep for days.