Implementation of an RTC on nrf52832 - drift issues

[rsoc16]

Hi--

I tried to implement an internally managed RTC using the app timer library, but came to find the error on that is too much for an RTC (~25 min lost over a few days). I started trying to find other alternatives, and came across this github repo: https://github.com/NordicPlayground/nrf5-calendar-example

The issue I am running into is it seems to be conflicting with my fStorage implementation in the code. Without the code built into my project, the fStorage functions fine as is. When the calendar code is brought in, the fStorage implementation keeps failing (with a no memory available error code designation). Is this expected? Does the calendar implementation conflict with the use of a soft device? Is there any way around it if it does?

[Ivan Herrera]

rsoc16 said:

Does the calendar implementation conflict with the use of a soft device? Is there any way around it if it does?

In the README of that example it is stated that this example does not support the softdevice. You can also see that it uses RTC0, which is used by the SoftDevice, so using these together will create issues for sure. RTC1 (if not using app_timer) and RTC2 should be free to use though.

[rsoc16]

Ah, im an idiot. Thanks, I swapped the defines for 

#define CAL_RTC NRF_RTC0
#define CAL_RTC_IRQn RTC0_IRQn
#define CAL_RTC_IRQHandler RTC0_IRQHandler

to

#define CAL_RTC NRF_RTC2
#define CAL_RTC_IRQn RTC2_IRQn
#define CAL_RTC_IRQHandler RTC2_IRQHandler

I still am having issues getting the callback going in the example after doing this. Is there something extra I need to do?

[Ivan Herrera]

Have you enabled RTC2 in sdk_config.h? 

[rsoc16]

Sike, never mind. Just got it. another stupid error. Sorry! Appreciate the quick help.

[Ivan Herrera]

No worries. Believe it or not but I was also looking at the calendar example today to figure out a way to keep track of time without app_timer, hence I knew why you were having trouble :)