nrF52 IOT SDK Run function periodically

[amjabb]

I am using a nrf52 DK and running the IOT Cloud CoAP Client example in the SDK. I need to run multiple functions periodically, and I need to be able to change the periods at which the functions run at dynamically. The example is making use of iot_timer_init and I can see that it is initializing a couple functions to run periodically, however once they are initialized I am not able to change the values. I am wondering what the best way to do this using the SDK. So that ideally normal program execution is still taking place while my functions are getting called.

[bjorn-spockeli]

I think the easiest approach is to use the application timer library(app_timer.c) to create repeating timers and call you functions periodically from their timeout callbacks.

[amjabb]

Would this work with the iot_timer running at the same time, also would I be able to change the period at which it runs dynamically or does it just initialize it once?

[amjabb]

I attempted following the tutorial on app_timer and it seems to be working, however it is never switching back to my iot timer once the timer is turned on. Also I should mention that the function which I am sending periodically are coap requests, so perhaps they are bound to the iot_timer?

[bjorn-spockeli]

It appears that the iot_timer and the app_timer uses the same RTC periperal (RTC1). The app_timer library is hardcoded to use RTC so I would not recommend modifying it. Instead I would use RTC2 directly with the nrf_drv_rtc.c and use that to call your periodic functions. See the RTC peripheral example in the examples\peripheral\rtc folder.

[amjabb]

Thank you for your help. I was able to continue using the RTC1 peripheral with the app_timer working along side the iot_time. For anyone who is looking at this as well I am sending up to five messages periodically using app_time, however I am doing significant data validation on the receiving end.