I am looking for a timer example which can be used to time the scanned packets interval in millisecond resolution

[PingISTL]

Dear All

Could you point me a timer example, can be used to time the interval in ms between something? like read the system time when something happens and then read again when it happens again?

Thank you!

Ping

[ovrebekk]

Hi Ping

You should be able to use the k_uptime_get() or k_uptime_get_32() functions for this. They will return the number of milliseconds that have passed since the system booted, either as a 64-bit or 32-bit value, and if you call this twice and compare the two values you can see how much time has passed. 

Best regards
Torbjørn 

[PingISTL]

Thanks, Torbjorn

That works fine.

I also need to create a timer to do a periodic task like blink a LED, I don't want to use k_sleep() , what is the best way to do it please?

I am sorry keep asking you the small questions like this, but I am new to Zephyr.

Thanks

Ping

[PingISTL]

Hello, Torbjorn

I refer the reference from here - https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/reference/kernel/timing/timers.html#using-a-timer-expiry-function as below:

   

void my_work_handler(struct k_work *work)
{
    /* do the processing that needs to be done periodically */
    gpio_pin_set(dev, PIN, (int)led_is_on);
	led_is_on = !led_is_on;
}

K_WORK_DEFINE(my_work, my_work_handler);

void my_timer_handler(struct k_timer *dummy)
{
    k_work_submit(&my_work);
}

K_TIMER_DEFINE(my_timer, my_timer_handler, NULL);

to flash a LED at 1s interval, it seems works fine, but I have another thread - uart echo like below:

K_THREAD_DEFINE(uart_write_thread_id, STACKSIZE, uart_write_thread, NULL, NULL,
		NULL, PRIORITY, 0, 0);

which stops working after I put the timer function.

Could you please tell me why?

Regards!

Ping

 

[ovrebekk]

Hi Ping

It is very odd that running the timer would cause your thread to stop functioning. 

Does it matter if you start the timer or not, or if you submit the work item or not?

Would you be able to share your main file with me, so I can see what your thread is doing?

I can make this case private if you don't want to share your code in a public case. 

Best regards
Torbjørn

[PingISTL]

Hi, Torbjorn

Thanks for your help, I tried the timer again and I think I have found a bug in my UART thread. It seems working fine now. 

I also tried the below thread for blink LED like the Thread sample:

void blink0(void)
{
	while(1) {
		k_sleep(K_SECONDS(1));
		gpio_pin_set(dev, PIN, (int)led_is_on);
		led_is_on = !led_is_on;	
	}
}
K_THREAD_DEFINE(blink0_id, STACKSIZE, blink0, NULL, NULL, NULL,
		PRIORITY, 0, 0);

Wonder what is the difference between two implements - the timer one and above thread one, my UART thread is similar to above blink0 , in terms of priority, are they same?

Regards!

Ping