Question about stopping all the timers that are used in the application.

[Rajat]

Hi Everyone

I have got 3 timers in my application. 

1 is repeated , and other two are Single shot which are ran from the inputs to the 1st Repeated timer.

The repeated keeps checking the UART for a byte , once the byte is received , One single shot timer is started , which on expiry turn One of my sensor OFF and inside the handler starts another single shot timer which again turns ON the sensor after 1 hour. 

If i stop the repeated timer when i turn OFF the Sensor , and start the Timer when I turn ON the sensor again. The whole thing just comes to a halt and it doesn't work anymore.

I have fixed this issue by using a timer of 10 seconds , which does literally nothing but keep repeating after 10 seconds, but i am not sure if the theory is correct or not.

""If all the timers have been turned OFF , the RTC goes to deep-sleep and it doesn't count anymore and to keep the RTC alive , i have used a repeated timer as desribed above.

It works in this configuration , but i am not sure if the reasoning is correct or not.""

Kindly help me understand this behavior.

Thanks 

Rajat

[Edvin]

Can you please specify a few things:
What is your LFCLK source? And what is your app_timer prescaler? 

As you can see from the documentation of the RTC, the resolution is not necessarily even 10m:

https://www.nordicsemi.com/DocLib/Content/Product_Spec/nRF52840/latest/rtc?664#concept_rvn_vkj_sr

I don't think I fully understand your requirements, but you need to have a timer running at all times, or do you not?

BR,

Edvin

[Rajat]

I am using BLE , so that by default would init the lfclk and app timer prescaler is 15 .

No , i need restart the stopped timer after certain duration of expiry of a different timer. . Works well for less than 10 minutes , but for a greater duration , it doesn't.

[Rajat]

For 1024 frequency , number of ticks is 30720 for 30000 interval of timer t1

[Rajat]

983040 are the ticks for 32768 frequency for same interval

[Edvin]

Is it possible for you to replicate your issue on one of the examples in the SDK without all the external HW, so that I can reproduce it?

Changing the APP_TIMER_CONFIG_RTC_FREQUENCY should not change the time it takes for the timeout. Only the timer resolution. I have tested it in this example, but it works as intended.

BR,

Edvin

[Rajat]

Is my software compiling on your end?

Because if it does , I can modify the same project that can work on PDK , Would it be okay?

Just want to know if everything is compiling properly without any errors.

[Edvin]

Rajat said:

Is my software compiling on your end?

 well, it wasn't. It was missing some logging files (I can't remember exactly which ones at this point in time). I removed everything except the app_timer things in order to compile. However I haven't been able get any timer callbacks with your project whatsoever. I have stripped away everything except the app_timer parts. Are you able to get interrupts if you have short timeouts?

Best regards,

Edvin