nrf54l15-dk rtc

[dede]

Hi,Team,

I'm currently using the nrf54l15-dk. I want to set the rtc of the nrf54l15-dk to obtain the timestamp. How should I configure the rtc? Which examples should I refer to?
My ncs version is v2.8.0.

Thanks.

[Kazi Afroza Sultana]

Hello,

The error shows that one variable you have declared or defined  (grtc_channel), but you have not actually used it anywhere in your code. This is a common warning or error in C/C++ development, especially when using strict compiler flags.

To resolve this, ensure that you use the variable in your code, for example by passing it to a function. Otherwise, you have to remove this.

Can you please share your application folder?

[Bruce2048]

Kazi Afroza Sultana The unused var won't cause build error.

The main reason is the header not exits.

I don't want talk more. just show your code which is a complete project.

It won't be difficult for your verder, but cost much time for us costumers.

Thanks.

[dede]

Hi

I can understand what you mean. But I don't know how to do it. Could you please provide an example of a code engineering project?

Thanks.

[Tom Weber]

This is how to read the GRTC:

In prj.conf:

CONFIG_NRFX_GRTC=y

In your code:

#include <nrfx_grtc.h>
...
uint64_t syscounter;
int ret = nrfx_grtc_syscounter_get(&syscounter);
if (ret != NRFX_SUCCESS) {
   ...
}

As for retained memory, see zephyr/samples/boards/nordic/system_off for an example.

[dede]

Hi,

Thank you very much for your reply.

Thank you very much for your reply.
Now I can use the nrfx_grtc_syscounter_get() function to obtain the value. The app will send 8 bytes to my device: 0x10, 0xDB, 0x4D, 0xEE, 0x98, 0x01, 0x00, 0x00. Converting these to 13-digit decimal gives 1756344736528. This represents a Unix millisecond-level timestamp format. Converting it again to UTC format results in 20-09-27 21:32:16.528.
The first time, nrfx_grtc_syscounter_get(&syscounter) was called, and syscounter = . A delay of 1 second was then applied. Subsequently, nrfx_grtc_syscounter_get(&syscounter) was called again, and syscounter = 1127894. Based on the difference you described, I should do this: 1756344736528 + 1127894 - 126117 = 1756335738305. Right? If I'm wrong, please let me know.
This is my simple test code:

    unsigned char bytes[] = {0x10, 0xDB, 0x4D, 0xEE, 0x98, 0x01, 0x00, 0x00};
	uint64_t timestamp = 0;

	// 从小端序字节构建64位整数
	for (int i = 0; i < 8; i++) {
		timestamp |= (uint64_t)bytes[i] << (i * 8);
	}
	// 输出时间戳（13位十进制数字）
	printf("\n");
	printf("Timestamp1: %" PRIu64 "\n", timestamp);
	uint64_t syscounter;

	ret = nrfx_grtc_syscounter_get(&syscounter);
	if (ret != NRFX_SUCCESS) {
 		 LOG_ERR("get grtc err");
	}
	printf("Timestamp2: %" PRIu64 "\n", syscounter);
	k_msleep(1000);
	ret = nrfx_grtc_syscounter_get(&syscounter);
	if (ret != NRFX_SUCCESS) {
 		 LOG_ERR("get grtc err");
	}
	printf("Timestamp3: %" PRIu64 "\n", syscounter);

The log printed by the device is as follows:

Timestamp1: 1756344736528
Timestamp2: 126117
Timestamp3: 1127894

Thanks.

[Tom Weber]

I suggest you do like this:

uint64_t offset = 0;

int set_time(uint64_t timestamp)
{
    uint64_t syscounter;
    int ret = nrfx_grtc_syscounter_get(&syscounter);
    if (ret != NRFX_SUCCESS) {
        return ret;
    }
    offset = timestamp - syscounter;
    return 0;
}

int get_time(uint64_t *timestamp)
{
    uint64_t syscounter;
    int ret = nrfx_grtc_syscounter_get(&syscounter);
    if (ret != NRFX_SUCCESS) {
        return ret;
    }
    *timestamp = syscounter + offset;
    return 0;
}

If you call set_time() with your initial timestamp, then k_msleep(1000), then get_time() should give the initial timestamp plus one second.

[dede]

Hi,

Thank you for your reply.
As you said, calling k_msleep(1000) indeed adds 1 second.

But how can I achieve adding 1 second to the timestamp? As I mentioned:
"The app will send 8 bytes to my device: 0x10, 0xDB, 0x4D, 0xEE, 0x98, 0x01, 0x00, 0x00. Converting these to 13-digit decimal gives 1756344736528. This represents a Unix millisecond-level timestamp format. Converting it again to UTC format results in 20-09-27 21:32:16.528." Currently, I can only calculate the 13-digit decimal number: 1756344736528. If I add 1 second to 1756344736528, converting it to UTC results in 2025-09-27 19:02:18.305, and the time is incorrect.
Could you please tell me how to add 1 second to the value of 1756344736528 to achieve the addition of year, month, day, hour, minute, second, and millisecond?

Thanks.

[Tom Weber]

The GRTC measures time in microseconds, not milliseconds. You need to convert between them.