How to enable and disable FreeRTOS tickless idle? Anyway to wakeup when there is BLE activities detected?

[inghowe83]

How to enable and disable FreeRTOS tickless idle(RTC or Systick)? Anyway to wakeup from tickless idle mode when there is BLE activities detected?

Setup:

1. nRF5_SDK_15.2.0_9412b96

2. Window 10

3. PCA10056

[Susheel Nuguru]

How to enable and disable FreeRTOS tickless idle(RTC or Systick)?

 tickless idle functionality is enabled by defining configUSE_TICKLESS_IDLE as 1 in FreeRTOSConfig.h

 

Anyway to wakeup from tickless idle mode when there is BLE activities detected?

This is done automatically for you, as tickless idle uses __WFE sleep, any activity will implicitly wake the chip and after processing is, the tickless mode will make the chip go to sleep again.

You might like reading this page. 

[inghowe83]

Thanks Susheel Nuguru,

Another question, during tickless idle mode. Have you guys seen any good example to overcome RTC clock drifting issue during Tickless IDLE on/off? We plan to have a external RTC driven World Clock for logging purpose.

[inghowe83]

Susheel Nuguru Thanks. I notice there is a similiar request (outdated) as per the link below.

https://devzone.nordicsemi.com/f/nordic-q-a/610/sample-code-for-rtc-to-update-current-time-of-device/3168

I want to keep track of the time using internal RTC and want to sync the time from a external device, such as a phone. 

And the most important part is...is there any sample code available? Thanks

[Susheel Nuguru]

Please take a look at the example provided in the SDK to get the current time from the peer device (if it implements the BLE CTS profile). 

[inghowe83]

Hi Susheel Nuguru

Thanks for the BLE CTS profile, do you know what are the best method to obtain tick offset when wakeup from tickless idle mode? If my device doesn't connect to BLE for long period of time, my time offset when wakeup from tickless idle mode and the logging data time stamp will have huge offset on it.

Please advice.

[Susheel Nuguru]

before the system goes to sleep and as soon as your device wakes up you can call xTaskGetTickCount() and you can do a diff and add the difference to the timestamp you are maintaining.

[inghowe83]

thanks!