APP_TIMER_KEEPS_RTC_ACTIVE SDK15.0 rtc does not start unless at least 1(one) timer is active

[theAdib]

APP_TIMER_KEEPS_RTC_ACTIVE SDK15.0 rtc does not start unless  at least 1(one) timer is active

I have set APP_TIMER_KEEPS_RTC_ACTIVE=1

And I want to use the app_timer module for some basic timestamping.

app_timer_init();
...
// failure here
uint32_t cnt = app_timer_cnt_get(); // cnt is always 0(zero) as RTC is not running

...
// WORKAROUND
app_timer_resume(); // starts RTC regardles not calling app_timer_pause()
// expected behaviour then
cnt = app_timer_cnt_get(); // cnt is is filled by some expected nonzero values

   

Above code shows the bug in the current SDK 15.0.

The workaround is to call app_timer_resume(); that will start RTC regardlesly.

I don't know the situation in other SDK version.

I use the option to have a monotonic upcounter like systick but without many interrupts and without wasting other timer.

@nordic please fix the bug.

regards, Adib.

--

[haakonsh]

Hey theAdib,

You need to call app_timer_start.

Cheers,

Håkon.

[theAdib]

HI Hakon,

I tried to do simple example without any instantiation of individual timers.

I would like to use the app_timer_cnt_get() function for some timing tests. for example check that initialisation does not last longer than xxx msec in an blocking synchronous way.

The use case might be timing calculation during init phase when there is no app_timer instantiated.

Saying that I would accept to call app_timer_start() only as a workaround not as a real solution.

Regards, Adib.

[haakonsh]

app_timer_init() does not start the app_timer whereas app_timer_start and app_timer_resume does...