Using app_timer_cnt_get(), get zero!

RE: Using app_timer_cnt_get(), get zero!

djqtsg — Wed, 28 Sep 2016 09:22:27 GMT

Uly, have you figured out solution to make timer work in interrupts? Can you post the code?

RE: Using app_timer_cnt_get(), get zero!

uly — Mon, 18 Jul 2016 19:01:26 GMT

@Ole Bauck, thanks very much, I made some changes and it works, I put what I did as an answer.

RE: Using app_timer_cnt_get(), get zero!

uly — Mon, 18 Jul 2016 18:18:21 GMT

I moved the app_timer_cnt_get functions into the main() part, then I notice the eclipsed time. Now I somehow understand the explanation of Timer library in the Nordic Semiconductor Infocenter, i.e.,

... The actual timer start/stop operation is executed by the SWI0 interrupt handler. Since the SWI0 interrupt is running in APP_LOW, if the application code calling the timer function is running in APP_LOW or APP_HIGH, the timer operation will not be performed until the application handler has returned. This will be the case e.g. when stopping a timer from a timeout handler when not using the scheduler.

I guess if proper levels are defined, I will make the time to work in the interrupts. I will do some tests on that.

RE: Using app_timer_cnt_get(), get zero!

Ole Bauck — Mon, 18 Jul 2016 15:47:02 GMT

Since you are in an interrupt/handler, app_timer will not start until the event handler is done (app_timer operations are done in a software interrupt). You have to check the counter value after the event handler.

RE: Using app_timer_cnt_get(), get zero!

uly — Mon, 18 Jul 2016 15:33:38 GMT

Hi, Ole, thanks. I don't know the timeout handler, there do exist a handler given to app_timer_create(), but it seems have nothing to do with timeout. To prevent the value of RTC to be 0, I added a delay before returning app_timer_cur. but app_timer_cur is still 0.

I put the main.c file https://codeshare.io/MLgBV, which is basically on the basis of the example from tutorial. I appreciate if you could have a look at part between line 59 to 70.

RE: Using app_timer_cnt_get(), get zero!

Ole Bauck — Mon, 18 Jul 2016 10:43:06 GMT

watchdog_timer will obtain the value of the RTC when you call app_timer_cnt_get(&watchdog_timer);.

Is the timeout handler corresponding to m_led_a_timer_id ever called (handler given in app_timer_create function)?

Right after starting the first timer you may expect that the value of the RTC is 0 (it does not start until the first app_timer_start is called). May this be the issue?

RE: Using app_timer_cnt_get(), get zero!

uly — Mon, 18 Jul 2016 06:53:46 GMT

One question, after declaring watchdog_timer, should I do something to let watchdog_timer obtain the value of RTC before app_timer_cnt_get(&watchdog_timer); ?

RE: Using app_timer_cnt_get(), get zero!

uly — Sat, 16 Jul 2016 18:49:51 GMT

@Ole Bauck, thanks, I declare watchdog_timer, app_timer_cur and app_timer_diff as global static, but still get ZERO.

RE: Using app_timer_cnt_get(), get zero!

Ole Bauck — Fri, 15 Jul 2016 09:19:59 GMT

Maybe not the root of your problem, but watchdog_timer should be declared as static to not be placed on the stack and destroyed when the function exits, or else app_timer_diff will always be equal to app_timer_cur.

But if I understood correct app_timer_cur is equal to zero even after app_timer_cnt_get(&app_timer_cur)?

RE: Using app_timer_cnt_get(), get zero!

uly — Fri, 15 Jul 2016 07:15:50 GMT

@RK, thanks. Yes, lfclk_request(); is called in the beginning of main() function. I have added the main() part in the question.

RE: Using app_timer_cnt_get(), get zero!

RK — Thu, 14 Jul 2016 23:55:48 GMT

Have you started a low frequency clock source?