QN9090 deep-sleep support in API commented out.

[icefire]

I am trying to put the QN9090 in deep-sleep mode. The function that is supposed to do this is POWER_EnterPowerMode in fsl_power.c, which takes as an argument the sleep mode the user wants the SoC to enter. This function contains functions to put the system in power-down mode and deep power-down mode, but the function for deep-sleep is commented out. When I inspect the commented function there appear to be parts missing related to the configuration of this sleep mode. 

How come this is commented out? Is it possible for me to request NXP to finish this part of the API?

[EduardoZamora]

Hello @icefire

Hope you are doing well.

Could you please provide more details about your development? Is it based on a BLE demo application from the QN9090 SDK?

Depending on your application, power-down mode could cover the deep-sleep mode in most of the cases. Please, take a look at the QN9090/QN9030 Power Consumption Analysis; this document provides information about the power consumption of this device, how hardware is designed and optimized for low-power operation and how the software is configured to achieve the best low-power profile.

Regards,
Eduardo.

[icefire]

Hello @EduardoZamora 

I hope you are doing well too!

I have to implement power-management into an existing application to make it more energy efficient. The application does make use of BLE, but it isn't necessarily based on the BLE demo application.

Ideally, both deep-sleep and power down get implemented so that depending on how long the system needs to sleep the system can be put in an optimal mode. The sleep durations are highly variable so both are preferred.

Power down sports higher energy savings than deep sleep but is harder to work with because it causes the program to reboot, which isn't something that will work well with our program. Unless there is a way to resume the program where it left off, the implementation of deep sleep is a must.

So how do I continue? Should I implement the deep-sleep API myself?

[EduardoZamora]

Hi,

Please, consider using any of the BLE demo applications from the SDK. I would recommend taking a look at the Temperature Sensor (temp_sens) and Temperature Collector (temp_coll), or Heart Rate Sensor (hrs) example projects inside the QN9090 SDK (wireless_examples > bluetooth). These examples could be used as a base to develop your application as they are highly configurable, allowing the user to set some relevant parameters and change the information being transmitted.

The Bluetooth examples from the SDK should switch power mode in idle task (App_Idle). Their mechanism should try to enter the lowest power mode available that the application allows in the idle task.

Regards,
Eduardo.

[icefire]

The BLE application we have made is built on the zephyr RTOS. Because of this it's not possible to configure the system to go into deep sleep through the use of the application-level API used in the BLE samples. To allow zephyr to drive the power consumption, power-management functions need to be hooked into zephyr so that zephyr can use them.

Having looked into how the BLE samples put the system to sleep, it appears they use the same function as described earlier, being the POWER_EnterPowerMode function in fsl_power.c. This is the function that allows the system to be put into power down and deep power down mode, and in which the function that supports deep sleep is commented out. There are some functions in the BLE framework which have the word deepsleep in them, but they lead back to functions which put the system into power down or deep down. It appears to me that the samples don't put the system into deep sleep, so the BLE samples are a dead end.

I could try to write my own implementation, but the lowest-level functions for putting the system to sleep are undocumented functions stored in ROM. I could use the same ROM-functions used in putting the system in power down and deep power down, but this is very risky as I could be missing vital functions and information for deep sleep specifically.

[EduardoZamora]

Hi,

Deep Sleep mode may not be currently supported in the SDK. You could try to develop your own implementation of this low-power mode, but please consider that our support may be limited, and some unexpected behaviors may occur.

Also, I would suggest redirecting any topic/inquiry related to Zephyr to their community.

Regards,
Eduardo.

[icefire]

I'd rather not have to implement this API because it seems you need in-depth knowledge as to the inner workings of the SoC, and access to ROM PM API functions, both of which I don't have. Is it possible for NXP to finish this API?

[EduardoZamora]

Hi,

My apologies, the only information currently available can be found in the Connectivity Framework Reference Manual (from QN9090 SDK documentation folder > docs > wireless > Common), Chapter 3.16 Low-power Library; and the QN9090/QN9030 Power Consumption Analysis.

Please, allow me to apologize again for any inconvenience this might cause you.

Regards,
Eduardo.