how to use rtc in nrf52840 dongle

[calivan]

Timer A with a 10-minute interval, timer B with a 4-hour interval, and timer C with a 10-second interval are required, and A and B should also run out of time in low power mode. Timer C only needs to flow for 10 seconds and remains (while generating a BLE signal) while the CPU is fully awake.

If I use softdevice, it says I can't use RTC0, is this right?
Then can I use timer A as RTC1 and timer B as RTC2?

Can I use two RTCs with different scale values?

I understand that APP_TIMER uses RTC1. Then should I not use APP_TIMER in my case?

Can I use TIMER using HFCLK for Timer C?

[Kenneth]

Typically the timeout needs to be set such that the RTC doesn't overflow, and depending on the prescaler value that may happen after 512 seconds. In your case I would have setup a timeout value of 60seconds and use a counter that increments, something like:

static uint32_t counter;

1minute_timeout_handler()
{
counter++;
if(counter%10 == 0)
  10minute_timeout_handler();
if(counter%240 == 0)
  4hours_timeout_handler();
}

Best regards,
Kenneth

[calivan]

thank you 

Do you know any example I can refer to? I use nrf52840 dongle. 

 

in your code,  'counter' isn't reset?