Restartig app_timer does not work with nRF52832 and SDK12.0.0

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Thu, 25 May 2017 07:42:28 GMT

As far as I can remember, in my code the stop/start calls were not in the timer's callback. Well, strange. I haven't had time to dig into this any more and I am now using nrf_drv_timer, instead.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Aaron — Wed, 24 May 2017 22:10:20 GMT

I ran into this problem also. It seems like app_timer does not like it when you call stop()/start() on a timer from that timer's callback. I moved the timer reset out of the callback and it seems to work.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Mon, 02 Jan 2017 11:30:19 GMT

Yep, I was thinking that too. Now I changed the bit width into 2 and got it working. Also, timer interval changing works now, with this nrf_drv_timer version, I mean. Thank you for help and patience!

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Mon, 02 Jan 2017 10:51:46 GMT

The default prescaler of the time is 0. So it will generate ticks with 16MHz tick. For 100ms with prescaler 0, you need to put 16MHz/10 = 0x186A00 in CC register. This is a 24 bit value.

Please check your nrf_drv_timer_config_t variable to see what .bitfield variable of it is initalized to. My guess is that it is initialized to TIMER_DEFAULT_CONFIG_BIT_WIDTH which is set to 0 = 16 bit. So instead of writing 0x 186A00, it writes only 0x6A00 = 1.69ms.

Solution is to change the TIMER_DEFAULT_CONFIG_BIT_WIDTH to 2 which is 24bit in timer register.

If this works, please accept the answer.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Mon, 02 Jan 2017 10:19:06 GMT

Okay, nrf_drv_timer_uninit() does it, of course. But now the interval seems to be incorret. Instead of 100 ms, I get something like 1 ms or 2 ms. Is there some hidden extra setting concerning the calls:

time_ticks = nrf_drv_timer_ms_to_ticks(&timer, interval_ms);
nrf_drv_timer_extended_compare(
     &timer, NRF_TIMER_CC_CHANNEL0, time_ticks, NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Mon, 02 Jan 2017 09:30:16 GMT

So, how do I deinitialize the timer in order to set new interval?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Mon, 02 Jan 2017 09:27:30 GMT

You get this error when you are trying to initialize an already initialized timer.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Mon, 02 Jan 2017 08:53:20 GMT

I also tried to solve the problem by using nrf_drv_timer instead of app_timer. However, my code fails on this:

nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
err = nrf_drv_timer_init(&timer, &timer_cfg, timeoutHandler);
APP_ERROR_CHECK(err_code); // err_code returns 0x00000008 !!
time_ticks = nrf_drv_timer_ms_to_ticks(&timer, interval_ms);
nrf_drv_timer_extended_compare(
     &timer, NRF_TIMER_CC_CHANNEL0, time_ticks, NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
nrf_drv_timer_enable(&timer);

So, nrf_drv_timer_init() fails with error code 8. What coul be the reason?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Mon, 02 Jan 2017 08:44:26 GMT

APP_TIMER uses RTC1, you cannot configure it.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Mon, 02 Jan 2017 08:39:55 GMT

How do I configure which timer instance APP_TIMER is using? In the code there is only this macro:

APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Tue, 13 Dec 2016 16:24:52 GMT

Yes. It is. Dfined as blocked in softdevice specification document

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Tue, 13 Dec 2016 12:00:31 GMT

Yeah, but what are those resources that softdevice uses, is the TIMER0 such a resource?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Tue, 13 Dec 2016 11:17:16 GMT

Hi Jarmo, Softdevice specifications says all resources that it uses and reserves which are not available to the application after softdevice is enabled.

The queue size depends on how fast you are pushing app_timer operations on a particular timer. Normally you would not need more than 4, but it depends on many things. I think the default in SDK is 10 items in the queue, that is max queue size is 10.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Mon, 12 Dec 2016 08:20:29 GMT

How do I know which timer app_timer is atually using? And what timer I should use? Is the TIMER0 reserved for soft device? My timer system initialization code is as follows:

  lfclk_config();
  APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);

Also, what is that "OP_QUEUE", actually, and how long the queue should be?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Mon, 12 Dec 2016 08:15:02 GMT

There is ofcourse possibility of mixing up with timers. Easy mistake is to use the same timer instance two times, then we get completely unexpected results. It is also possible to configure PPI to trigger timer tasks with other events. In you case if you are not using TIMER0 and if you are not not reconfiguring the timer you use and not using PPI around it, then i do not know what else is wrong. Like I said it will be much easier if you upload more code.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Fri, 09 Dec 2016 14:53:58 GMT

Is it possible to somehow mix-up timers with soft device (conflicting with TIMER0, TIMER1 etc.)? It seems that the problem might be related to softdevice, since the problem occurs when connecting / disconnecting. I am changing the timer interval at those moments.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Fri, 09 Dec 2016 13:51:58 GMT

for sure the problem is somewhere else in your project.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Fri, 09 Dec 2016 13:45:54 GMT

Not sure what the problem is in your code. I tested app_timer with this example and it showed correct results

main.c

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Fri, 09 Dec 2016 12:50:58 GMT

Thanks! The problem arises when I change from 100 ms interval to 50 ms interval, and vice versa. The related code is shown above, in the original question. Could it be possible that the underlying hardware counter is not cleared and when the compare value is changed, first firing of the comparison is missed (because counter has already passed the value) and the timer starts to fire only after the counter rolls over back to zero?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Fri, 09 Dec 2016 12:14:55 GMT

re-opened , please give some more details

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Fri, 09 Dec 2016 10:30:19 GMT

I would need >200 points to reopen the question. I am now hitting hard into the same problem :( Can you please reopen this question?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Thu, 01 Dec 2016 13:54:37 GMT

don't hesitate to reopen this if you see this behavior again Jarmo. Since you started this thread, you are allowed to re-open it.

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Thu, 01 Dec 2016 12:21:21 GMT

Sigh, put wrong closing reason. Can't change it any more, maybe you could do that?

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Jarmo — Thu, 01 Dec 2016 12:19:31 GMT

Yeah, for now it looks like so :)

RE: Restartig app_timer does not work with nRF52832 and SDK12.0.0

Susheel Nuguru — Thu, 01 Dec 2016 12:18:12 GMT

maybe we can close this then Jarmo?