Zephyr RTC build issue.

[Mark P Clark]

Greetings,

 In the process of adding the RTC driver to the project I am encountering a build error when I try to setup a device pointer. The offending line is:

 const struct device *rtc_ptr = DEVICE_DT_GET(DT_NODELABEL(rtc0));

In prj.conf I have added:

CONFIG_RTC=y

CONFIG_NRFX_RTC0=y

CONFIG_COUNTER=y

The build error message is:

C:/ncs/v2.9.0/zephyr/include/zephyr/device.h:92:41: error: '__device_dts_ord_82' undeclared here (not in a function); did you mean '__device_dts_ord_2'?

   92 | #define DEVICE_NAME_GET(dev_id) _CONCAT(__device_, dev_id)

It appears that the device driver is not being compiled based on this error message. I am using V2.9.0 of the Zephyr SDK and building on a Windows PC with VS Code.

The configuration board target is nrf52dk/nrf52832

Are additional Kconfig options required to be enabled?

I am able to compile calls to RTC functions that don't require the device pointer such as:

rtc_time_to_tm( struct rtc_time *);

Thanks for any help with this issue!,

Best regards,

Mark

   

[deiwo]

Hi, this usually happens when the RTC module is disabled in the board definition. Do you have it enabled?

[Mark P Clark]

Greetings and thanks for the input!

I modified the nrf52dk_nrf52832.overlay file to add this:

/ {

    chosen {

        nordic,nrf-rtc = &rtc0;

    };

};

In \zephyr\zephyr.dts - RTC is included as follows:

rtc0: rtc@4000b000 {

                                   compatible = "nordic,nrf-rtc";

                                   reg = < 0x4000b000 0x1000 >;

                                   cc-num = < 0x3 >;

                                    interrupts = < 0xb 0x1 >;

                                    status = "disabled";

                                    clock-frequency = < 0x8000 >;

                                    prescaler = < 0x1 >;

};

Building with the line offending line commented: // const struct device *rtc_ptr = DEVICE_DT_GET(DT_NODELABEL(rtc0)); 

and the .overlay change above results in a similar error:  

 C:/ncs/v2.9.0/zephyr/include/zephyr/device.h:92:41: error: '__device_dts_ord_DT_CHOSEN_nordic_nus_uart_ORD' undeclared here (not in a function)
92 | #define DEVICE_NAME_GET(dev_id) _CONCAT(__device_, dev_id)

Perhaps, there is a better way to enable RTC in the board definition?

Thanks and Best regards,

Mark

[deiwo]

I suggest adding this to the overlay instead what you have:
&rtc0 {
    status = "okay";
}

And I would not comment out the offending line, it should work if the rtc is enabled properly.

I recommend reading the tutorial on how to use the devicetree here: https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/lessons/lesson-2-reading-buttons-and-controlling-leds/topic/devicetree/

and here is the tutorial for the overlays: https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/lessons/lesson-3-elements-of-an-nrf-connect-sdk-application/topic/configuration-files/

What you should do is similar to what they did in the tutorial for overlays with spi, but in your case it should be rtc.

[Mark P Clark]

Greetings and thanks for the additional input!

 Initially I tried changing the nrf52dk_nrf52832.overlay file which gave me the same build error. Revisiting the l3_e2 tutorial; I used the DeviceTree Visual Editor and under SOC I could see that the rtc0/1/2 were not enabled. after enabling rtc0 it updated app.overlay file at the same level as the /src directory. This added:

&rtc0 {
status = "okay";
};

 After that I am able to build successfully and setup the device pointer as follows: 

const struct device *rtc_ptr = DEVICE_DT_GET(DT_NODELABEL(rtc0));

I would have expected the overlay file in /boards to have the same effect, evidently the app.overlay file takes precedence.

 Thanks much for your help with this issue!

Best regards,

Mark   

[Dhivin John]

Hi, 

I wanted to clarify — were you actually able to use any Zephyr RTC API functions (like rtc_get_time() or rtc_set_time()) with that rtc_ptr, or did the code just compile successfully only?

Just wanted to confirm if the RTC hardware is functionally working under Zephyr’s RTC API, or if it’s just a build-time symbol resolution fix.

Thanks,