NRF_DELAY_MS blocks interrupt

nrf_delay should be used basically never.  I think they put it in there to keep people happy who still remember basic.

The nrf_delay operates by executing a series of __nop (ie, no operation opcode). Since this just hangs up the processor during the delay it won't service your interrupt depending on the interrupt priority.

Senchoi said:

Do you mean that using nrf_delay in rtc_handler or timer handler will temporarily stop timer or rtc counting up?

No, the RTC and TIMER peripherals are HW peripherals. They will keep running regardless of what the CPU does, until they are stopped.

nrf_delay will only stall the CPU, causing higher current consumption (CPU running), and preventing CPU from performing other tasks.

Senchoi said:

Do you mean that using nrf_delay in rtc_handler or timer handler will temporarily stop timer or rtc counting up?

No, the RTC and TIMER peripherals are HW peripherals. They will keep running regardless of what the CPU does, until they are stopped.

nrf_delay will only stall the CPU, causing higher current consumption (CPU running), and preventing CPU from performing other tasks.