Interrupt using RTC

[hrms]

I want to monitor the RTC count and generate an interrupt when a specific count is reached. And without stopping the RTC, I want to generate an interrupt again when the next specific value is reached. Rather than restarting like a timer, the RTC must keep running. Can this be implemented?

[example]

RTC[0] count = 100000 -> interrput

RTC[0] count = 200000 -> interrput

RTC[0] count = 400000 -> interrput

[Turbo J]

Yes - and it is already implemented in the app_timer module of the nrf sdk.

[Jørgen Holmefjord]

Hi,

The RTC peripheral has 3-4 CC registers that you can set to different count values, The RTC will run until you clear it.

If you are using the RTC driver in the SDK, you can use nrf_drv_rtc_cc_set() to set multiple CC values, the second parameter to the function depicts the CC channel number.

Best regards,
Jørgen

[hrms]

How can I keep working even if the RTC overflows and clears?

[Jørgen Holmefjord]

That depends on how you have configured the RTC peripheral. The RTC driver will disable the interrupts in the interrupt handler. If you want the interrupt to be triggered after an overflow, you will need to remove this line, or call nrf_drv_rtc_cc_set() again to re-enable the interrupt. It is also possible to enable interrupts for the overflow event, by calling nrf_drv_rtc_overflow_enable().