Trying to get working RTC with BLE

Question

I'm trying to use real time clock with BLE and softdevice. My app based on ble_app_cts_c example and calendar ( https://github.com/NordicPlayground/nrf5-calendar-example ) 
 The idea is to connect board to time service on mobile, get current date and time and init the time clock of my board. 
 Calendar uses RTC0, but ble uses RTC0 and I decided to use RTC1, but got the issue, that RTC1 irq is implemented in 2 different files app_timer.h and one else, also I found that the best way is to create new timer with repeated mode (i.e. every 1 sec) and use them but got also errors with RTCs 
 What is the best way to use date on clock in ble device not calling each time mobile service to get current data?

haakonsh · Accepted Answer

Hey IlyaM, 
 RTC1 is most likely used by the app_timer library. You will need to implement the calendar timer as an app_timer, see Timer library . 
 You need some external source of accurate clock to update the local clock. From nrf_calendar.h: " 
 // Sets the date and time stored in the calendar library. 
 // When this function is called a second time calibration data will be automatically generated based on the error in time since the 
 // last call to the set time function. To ensure good calibration this function should not be called too often 
 // (depending on the accuracy of the 32 kHz clock it should be sufficient to call it between once a week and once a month). 
 " 
 I do not know how accurate your implementation with app_timer will be so I cannot say how often you will need to update the timer. 
 Cheers, 
 Håkon.

Trying to get working RTC with BLE

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