internal RTC example

RE: internal RTC example

Sigurd — Wed, 18 Mar 2020 13:52:04 GMT

[quote userid="87403" url="~/f/nordic-q-a/59164/internal-rtc-example/240319"]I want a real time clock that knows it is March 17,202 and will know months, days, leap years etc.[/quote]

The RTC is not a real time clock, its a real time counter. For this calendar use-case, please have a look at this and this post.

RE: internal RTC example

Timothy — Tue, 17 Mar 2020 18:19:07 GMT

Sigrud

yes I know how to use the timers. that is not what I want here. I will use the timers for other things in the application. I want a real time clock that knows it is March 17,202 and will know months, days, leap years etc. I loaded and ran the RTC example you pointed me to. it did nothing so I assume I did not do the following.

Starting nrfx rtc sample!
To run in non-secure mode, you need to add RTC0 to spm.c

I did not understand what this meant. what do I need to add and where do I add it to spm.c. if this is a real RTC then this is what I need. I could not find the supporting documention (apis, etc.).

RE: internal RTC example

Sigurd — Tue, 17 Mar 2020 10:38:04 GMT

Hi,

You can take a look at this sample, it uses the RTC directly.

But for most use-cases, you should use the kernel timer instead (the kernel timer uses the RTC). See this page

Snippet:

struct k_timer single_shot_timer;
struct k_timer multi_shot_timer;

static void my_expiry_function_1(struct k_timer *timer)
{
	ARG_UNUSED(timer);
	printk("single_shot_timer expired\n");

}

static void my_expiry_function_2(struct k_timer *timer)
{
	ARG_UNUSED(timer);
	printk("multi_shot_timer expired\n");

}

void main(void)
{
	printk("The kernel timer sample started\n"); // Doc: https://docs.zephyrproject.org/latest/reference/kernel/timing/timers.html

	/* start one single shot timer that expires after 5000 ms */
	/* start one multi shot timer that expires after 5000ms, and then every 5000 ms */
    k_timer_start(&single_shot_timer, K_MSEC(5000),             0);
	k_timer_start(&multi_shot_timer,  K_MSEC(5000), K_MSEC(5000) );
}

K_TIMER_DEFINE(single_shot_timer, my_expiry_function_1, NULL);
K_TIMER_DEFINE(multi_shot_timer,  my_expiry_function_2, NULL);