Entering power management mode

RE: Entering power management mode

Hung Bui — Wed, 06 Sep 2023 09:32:26 GMT

Hi Sharon,
You still need the nrf_ (the header .h file) in some cases it's used by the nrfx layer. Please follow what we have in the example in the SDK.

RE: Entering power management mode

Sharon Vardi — Tue, 05 Sep 2023 15:19:43 GMT

[quote userid="2121" url="~/f/nordic-q-a/103296/entering-power-management-mode/444544"]You can't use the higher driver if you don't enable lower layer.[/quote]

That's The answer I was looking for.
So in order to use the nrf_drv layer I need to also enable the nrfx_ layer since the nrf_drv uses the nrfx_ functions.

Regarding the nrf_ functions (Hardware access layer) - it's deprecated and only there for backward compatibility so it's recommended to not use those?

RE: Entering power management mode

Hung Bui — Tue, 05 Sep 2023 14:18:05 GMT

Hi Sharon,
I don't really get it , why you want to disable nrfx_rtc ?
The nrf_drv_rtc is very thin, it's only the overlay over the nrfx_rtc with no added feature.

The RTC is always there on the register level, all the layers are there just to help you to make it easier to use the module.

You can't use the higher driver if you don't enable lower layer.

RE: Entering power management mode

Sharon Vardi — Tue, 05 Sep 2023 11:17:54 GMT

Hi Hung,

If I'm Enabling the nrf_drv_rtc for example:

but I'm disabling the NRFX RTC peripheral driver:

1.Does the processor still acknowledges the RTC peripheral?

2. How can I acces the RTC peripheral - by using nrf_drv_ functions only? or beacuse the nrf_Drv layer using the nrfx_ layer function I'll still be able to use nrfx_rtc functions?

And in a more zoom-out prespective:
Does the FreeRTOS processor changes the way he interpret our code according to the layers we enable?
Does it have any meaning to if higher layer library is enabled above lower layer library?

RE: Entering power management mode

Hung Bui — Tue, 05 Sep 2023 10:46:37 GMT

Hi Sharon,

We have multiple layers. For example with UART, the highest level library is app_uart, then one layer under app_uart is nrf_drv_uart. The driver in turn use the nrfx_uart HAL layer to access the UART. (nrfx uses nrf_uart.h to access the hardware register).
Depends on your application you can choose to access UART directly using nrfx or you can use the driver or the app. Each layer on the top will provide you more feature and flexibility so that your application doesn't need to worry about the buffer , or handling the UART interrupt for example.

Please aware that nRF5 SDK is deprecated and no longer having any development. The current SDK platform we recommend is NRF Connect SDK.

RE: Entering power management mode

Sharon Vardi — Tue, 05 Sep 2023 10:14:46 GMT

1.Not yet but I'll give it a look, thank you.

2. Regarding the nrf_ and nrfx_ - in our sdk_config.h, what are we supposed to configure between the three of them? I understood the diffrenece between the three, but if we want to make a sustainable code for the future we shoukd use the nrfx_ alone?

RE: Entering power management mode

Hung Bui — Tue, 05 Sep 2023 09:29:25 GMT

Hi Sharon,

Have you tried our ble_app_hrs_freertos and verify the power consumption ?
__WFE will exist when there is an application interrupt.

Regarding the nrf_drv, nrf_ and nrfx_ .
The nrf_drv is using nrfx_ as the HAL back end.

The way it works is that we defined the nrfx_ to replace nrf_HAL. But there still some place nrf_ is included but it's only for backward compatible and in some cases, just the header file needed.

RE: Entering power management mode

Sharon Vardi — Sat, 02 Sep 2023 17:04:04 GMT

Hi Hung,
I have tried to use the power_management_run() function but is seems to exit the function. if there is no task running what other event (beside task timer interrupt) can cause the function to pass the __WFE line and finish her execution?

In a different manner - what is the hierarchy between nrf_drv (legacy layer) function, nrf_ (HAL functions) and nrfx_ functions if all of them are enabled within our sdk_config.h file?

RE: Entering power management mode

Hung Bui — Thu, 31 Aug 2023 11:05:06 GMT

Hi Sharon,

Could you let me know what exactly in power_management_run() function you have ?
Note that with freeRTOS included, the idle task will put the CPU to sleep. For example when BLE is not active (between connection event for example) the CPU will be put to sleep and you will have low power consumption.

2. When a peripheral is not used it will not draw current.

My suggestion is to try taking a look at our example and do power profiling on it to get an idea on how the power consumption is in an BLE application.