Sample at 500us

[joaodullius]

What would be the best way to guarantee that a procedure is execec is started at every 500us with high accuracy?
I'm using a nRF5340DK board and tried this both approaches. I'm toggling the leds and looking at an osciloscope the results.

Approach 1 - k_usleep and k_thread_define:

void gpio_thread(void)
{
	while(1) {
		gpio_pin_set(dev_led0, PIN_LED0, (int)led0_is_on);
		led0_is_on = !led0_is_on;
		k_usleep(500);
	}
}
K_THREAD_DEFINE(gpio_tid, 500,
                gpio_thread, NULL, NULL, NULL,
                -1, 0, 2000);

By this method I'm getting tooglings around 500 to 700us, with different sizes on the high and low periods.

Approach 2 - timer with K_USEC

void gpio_timer_handler(struct k_timer *dummy)
{
    gpio_pin_set(dev_led1, PIN_LED1, (int)led1_is_on);
	led1_is_on = !led1_is_on;
}
k_timer_start(&timer_led1, K_USEC(500), K_USEC(500));

By this approach I'm getting better results, closer to 500us, but with high variance on the value.

What would be the best way to achieve such fixed 500us results?

[joaodullius]

Considering the above scenario, what would be needed to change Zephyr tick from 1ms to 500 us?