Feather nRF52840 RTC (Real Time Counter)

RE: Feather nRF52840 RTC (Real Time Counter)

Menon — Wed, 26 Jun 2024 08:48:38 GMT

Hello,

I'm glad to hear that you resolved your issue.

Kind regards,

Abhijith

RE: Feather nRF52840 RTC (Real Time Counter)

Leytronix — Wed, 26 Jun 2024 08:25:31 GMT

Hello,

I now have found a solution by using the watchdog timer to wake-up from sleep instead of the RTC.

Cheers!

Tjerk

RE: Feather nRF52840 RTC (Real Time Counter)

Leytronix — Tue, 25 Jun 2024 05:41:44 GMT

Hi,

Now I am using SDK version 17.1.0 but am getting errors compiling the RTC example:

In file included from src\RTC.cpp:5:0:
include/nrf_drv_clock.h:100:1: error: 'ret_code_t' does not name a type; did you mean '__mode_t'?

Best regards,

Tjerk

RE: Feather nRF52840 RTC (Real Time Counter)

Menon — Mon, 24 Jun 2024 11:30:19 GMT

Hello,

There have been some changes with certain SDK versions. Please let me know if the thread I referred to was helpful.

Kind regards,
Abhijith

RE: Feather nRF52840 RTC (Real Time Counter)

Leytronix — Mon, 24 Jun 2024 11:15:22 GMT

Dear Abhijith,

I do not know which SDK version is used but I am using PlatformIO with the following configuration:

[env:nrf52840]
platform = nordicnrf52
board = adafruit_feather_nrf52840
framework = arduino
Kind regards,
Tjerk

RE: Feather nRF52840 RTC (Real Time Counter)

Menon — Mon, 24 Jun 2024 11:04:33 GMT

Hello,

Could you please tell me which SDK version you are using here? Please take a look at this old Devzone thread; it discusses something very similar.

Kind regards,
Abhijith

RE: Feather nRF52840 RTC (Real Time Counter)

Leytronix — Mon, 24 Jun 2024 09:02:06 GMT

I now have code for the RTC0 interrupt (see below). However, after calling initRTC the IRQHandler is not triggered. What should I do to get the interrupt working?

Thanks,

Tjerk

---------------------------------------------------------------------------------------------------------------------------------------------

#include <nrf.h>

extern "C" void RTC0_IRQHandler(void) {
    if (NRF_RTC0->EVENTS_TICK) {
        NRF_RTC0->EVENTS_TICK = 0; // Clear the event

    }
}

// Code for controlling the internal 24-bit RTC (Real Time Counter) with 12-bit prescaler
// RTC is clocked by the on-board 32kHz crystal

void initRTC()
{

    // Start the LFCLK source
    NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_Xtal; // Use external crystal

    NRF_CLOCK->TASKS_LFCLKSTART = 1; // Start LFCLK
    // Wait for LFCLK to start
    while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);
    NRF_CLOCK->EVENTS_LFCLKSTARTED = 0; // Clear the event

    // Clear RTC registers
    NRF_RTC0->TASKS_STOP = 1;
    NRF_RTC0->TASKS_CLEAR = 1;
    NRF_RTC0->PRESCALER = 327; // Prescaler to get a 1ms tick
    NRF_RTC0->EVTENSET = RTC_EVTENSET_TICK_Msk; // Enable TICK event
    NRF_RTC0->INTENSET = RTC_INTENSET_TICK_Msk; // Enable interrupt for TICK event

    // Clear any pending interrupts
    NVIC_ClearPendingIRQ(RTC0_IRQn);

    // Enable the RTC interrupt in the NVIC
    NVIC_EnableIRQ(RTC0_IRQn);

    // Start the RTC
    NRF_RTC0->TASKS_START = 1;

}