nRF52840/nRF5340 + nRF7002 with external MCU

[djgj]

Hello,

     We are evaluating a solution for our product where we would like to use

• Zephyr RTOS with NCS
• nRF52840/nRF5340 + nRF7002 for a combined WiFi/BLE solution. nRF52/53 will run the code for both BLE and WiFi combo.
• an External MCU which is not from one of Nordic MCUs.

Is it possible to use this combination for using nRF combo only as connectivity solution?
Is there an example already on zephyr or NCS for this solution? Can you guide us to relevant samples or documents on this?

Is there anything we would need to take care in this combination? How does interfacing with nRF52/53 MCU in this case looks like?

I feel firmware update might be difficult but not impossible?

Thank you for your support.

Regards,

DJ

[AHaug]

Hi,

Is it possible to use this combination for using nRF combo only as connectivity solution?

Yes, this is possible. The nRF7002 can be used together with either the nRF52840 or the nRF5340, and we use nRF5340 in the nRF7002DK due to the addition of the netcore and the additional computational power.

You can also use this combination (52840/5340+7002) in addition to an external MCU, but you will have to create your own solutions for interfacing between them w.r.t regular "activities" and w.r.t DFU and flashing of the devices. We do unfortunately not have any out of the box solutions for how to use an external mcu in a two/three-chip solution since it's hard to create a generic 1-solution fits all potential candidates as an external MCU.

Is there an example already on zephyr or NCS for this solution? Can you guide us to relevant samples or documents on this?

You can find a list of WiFi samples here: https://docs.nordicsemi.com/bundle/ncs-2.6.99-cs1/page/nrf/samples/wifi.html and I would specially point to the BLE coexistence sample: https://docs.nordicsemi.com/bundle/ncs-2.6.99-cs1/page/nrf/samples/wifi/ble_coex/README.html as well as the Wi-Fi fundamentals course on our academy pages https://academy.nordicsemi.com/courses/wi-fi-fundamentals/ (there is also a BLE course if thats of any interest).

I would also recommend that you start with the nRF7002DK (which features the nRF5340) as a starting point w.r.t investigating the samples.

How does interfacing with nRF52/53 MCU in this case looks like?

https://docs.nordicsemi.com/bundle/ncs-2.6.99-cs1/page/nrf/device_guides/nrf70.html and the subopages under https://docs.nordicsemi.com/bundle/ncs-2.6.99-cs1/page/nrf/device_guides/working_with_nrf/nrf70/developing/index.html should explain this quite well

Let me know if this is enough to get you going!

Kind regards,
Andreas

[djgj]

Hello,

    Thank you very much for the response.
I will take a look at those documentations.

Also w.r.t interfacing options
Can you kindly suggest/share your opinion on these interfacing? which might be better in terms of simplicity? Provided we have experience working with Nordic MCUs for BLE. 

Regards,

Dhananjay

[AHaug]

Hi,

Based on my current knowledge I would recommend you to go with option 2 since the nRF7002 is designed to be a companion chip around having a nRF device with sufficient memory as the host device. It might be possible to use a non-nRF companion device, but we don't have much support for this out of the box so it will depend heavily on your own proprietary solutions and investigations. There might be more support for solutions like option 1 in the future, but as of now it is quite limited. 

https://docs.nordicsemi.com/bundle/ncs-2.6.99-cs1/page/nrf/device_guides/working_with_nrf/nrf70/developing/constrained.html#host-soc-support, which is a subpage of one of the links I sent in my previous replies is also a good pointer to focus on w.r.t choosing a host-soc

Kind regards,
Andreas

[AHaug]

I can also add that the nRF7002DK can be illustrated as a reduced version of your option 2

  

Kind regards,
Andreas

[djgj]

Hello AHaug,

       Thanks for your response. We had to use a non-nRF host because of our project requirements
I have another question related to this.
In the zephyr project, i see this PR https://github.com/zephyrproject-rtos/zephyr/pull/75714

Where i assume nRF7002 support is added to the zephyr project.
does this mean we can now use nRF7002 with non-nRF MCU host? Will there be any impact on copyrights when running WPA supplicant on non nRF MCU?

Thanks,

djgj

[Marte Myrvold]

Hi,

Yes, that PR adds the nRF70 driver in the upstream Zephyr project.

The driver in Zephyr is under the Apache License 2.0, while the nRF Connect SDK is under LicenseRef-Nordic-5-Clause, so you do not need to follow the same terms and conditions for using the upstream Zephyr driver as for using the nRF Connect SDK.
However, I recommend contacting Nordic sales in your area for questions regarding copyright and licensing. See Contact Us.

Best regards,
Marte

[djgj]

Thanks a lot for the clarification Marte.

Do you know if there will be any significant disadvantage when choosing non-nRF host for using this companion nRF7002?
Network stack are all from zephyr in case of NCS too as i understand.
Is there any significant library in NCS that would be needed in non-nRF host that i am missing?

Regards,
djgj

[Marte Myrvold]

Hi,

Some disadvantages would be the test level, as we cannot test for all devices. Due to this, there might be compatibility issues with helper libraries, such as the download library. Additionally, we might not be able to provide the same level of support with a third-party host.

Best regards,
Marte

[djgj]

hello,

   Thank you for the response. which download library do you mean? is it useful for updating the firmware of nRF7002?

Regards,

djgj

[Marte Myrvold]

Hi,

The Download client library, but this was just an example of one of the helper libraries for the nRF7002.
Another thing to mention is that even though the driver is supported in upstream Zephyr, there might be helper libraries available in the nRF Connect SDK that are not in Zephyr. These are not required, but they might provide more features or better support for the nRF7002 than libraries in Zephyr.

Best regards,
Marte

[djgj]

Thank you Marte.

I will take a look at the libraries we might need.

Also is there any option to update the firmware of nRF7002 in the field?

Also do you have any comment on BLE/WiFi coexistence when using with nRF5340 vs non-nRF MCU?
Is Coexistence only supported if we use BLE softdevice Controller? will there be any support in Zephyr regarding this when using nRF7002?

regards,

djgj

[Marte Myrvold]

Hi,

djgj said:

Also is there any option to update the firmware of nRF7002 in the field?

Yes, you can update the nRF7002 firmware in the field. We do not have any samples showing the complete process of this as of now, but the Download client sample can be used as a starting point for downloading a firmware update. After the firmware image is downloaded, you can use the available DFU alternatives described in the Device Firmware Updates page. You can find more information in the nRF70 Series - Firmware patch update page.

djgj said:

Also do you have any comment on BLE/WiFi coexistence when using with nRF5340 vs non-nRF MCU?
Is Coexistence only supported if we use BLE softdevice Controller? will there be any support in Zephyr regarding this when using nRF7002?

If the host MCU uses the SoftDevice Controller, you can use coexistence based on the Short-Range Protocols External Radio Coexistence provided by the Multiprotocol Service Layer (MPSL) library, also called the MPSL CX API. The nRF Connect SDK provides a wrapper that configures coex based on devicetree and Kconfig options. You can read more about this in Coexistence based on MPSL CX API and nRF70 Series Wi-Fi coexistence.

With a third-party host, the specific details of Bluetooth and Wi-Fi coexistence might depend on the host's capabilities and configurations. We do have some general information on coexistence in nRF70 Series Bluetooth LE/IEEE 802.15.4 Coexistence and in the nRF7002 datasheet.

Best regards,
Marte