Delayable Work time deviation

RE: Delayable Work time deviation

Håkon Alseth — Tue, 20 Feb 2024 14:33:59 GMT

Hi,

Can you share a cut-down/simplistic example showing the issue?

Kind regards,

Håkon

RE: Delayable Work time deviation

creative.industry.ag — Tue, 20 Feb 2024 12:18:56 GMT

Hello Håkon Alseth

There is one custom thread called every 51 seconds and 3 channels ADC which have the same issue(ADC callbacks are called every 109ms)

ADC sequence configuration:

const struct adc_sequence_options mSequenceoOptions = {

.interval_us = 100 * 1000,

.callback = &ADC_callback,

};

Edit:
When I increase wok delay time to 1 sec, then deviation increase to 90ms. So I have constant 9% time deviation.

RE: Delayable Work time deviation

Håkon Alseth — Tue, 20 Feb 2024 11:18:41 GMT

Hi,

Are you certain there's no other threads queued in your system?

Here's a quick test firmware based on hello_world:

/*
 * Copyright (c) 2012-2014 Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <stdio.h>
#include <zephyr/kernel.h>
#include <hal/nrf_gpio.h>

#define LED0 28

static struct k_work_delayable blink;

static void blink_handler(struct k_work *work)
{
	nrf_gpio_pin_toggle(LED0);
	k_work_reschedule(&blink, K_MSEC(100));
}

int main(void)
{
	nrf_gpio_cfg_output(LED0);
	k_work_init_delayable(&blink, blink_handler);
	nrf_gpio_pin_clear(LED0);
	k_msleep(500);
	nrf_gpio_pin_set(LED0);
	k_work_reschedule(&blink, K_MSEC(100));
	printf("Hello World! %s\n", CONFIG_BOARD);
	return 0;
}

And here's the boot-up sequence:

It is consistently showing 100 ms at my end.

Kind regards,

Håkon