Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Tue, 12 Aug 2025 19:57:32 GMT

We have online courses for getting started with the nRF Connect SDK here: Nordic Developer Academy.
DFU is covered in Lesson 9 of the nRF Connect SDK Intermediate course.

This is also a good starting point: Bootloaders and DFU.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

nabeela — Tue, 12 Aug 2025 19:55:07 GMT

awesome thank you for that explanation, I'll dig into that and see if it's a viable solution to explore.

If you do have some links handy for the MCUboot two-slot DFU, please share.

thanks again.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Tue, 12 Aug 2025 19:52:44 GMT

Yes, it is possible, but maintaining that might be tricky.

The idea is that you use two-slot DFU with MCUboot with swapping, and keep the "alternate" application in the secondary slot.
The "main" application in the primary slot can trigger a test swap. At the next reset, the "alternate" application will be swapped to the primary slot and boot.
If the "alternate" application needs to survive power cycles and/or reset, it can mark itself confirmed. Then, it becomes the "main" application, and the previous "main" app becomes "alternate."
If the "alternate" application doesn't mark itself confirmed, at the next reset, it will be swapped back.

Note that DFU will still download the updated application onto the secondary slot, overwriting any "alternate" application staying there at the time. You will need to devise a plan around that.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

nabeela — Tue, 12 Aug 2025 19:36:58 GMT

got it thank you -- one last question that is related but a different strategy:

Would I be able to store 2 firmware images - one for a Matter only firmware (either wifi or thread, not switchable), and a separate image that is wifi only (for AWS integration - such as AWS IoT example).

if default image (matter firmware) is in the internal flash, and the secondary image (AWS IoT Wifi) is in the external flash, and a user can switch the working image. Maybe external flash can keep both image, but only one is loaded to nRF5340 at any one time - like a DFU operation, but 2 images are pre-loaded to external flash and user can switch between them.

There is a product in the market that does this (I don't think it's using Nordic chipset, but it's an example)

https://www.kwikset.com/products/detail/halo-select-touchscreen-wi-fi-and-matter-enabled-smart-lock

If that's not at all possible, no problem.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Tue, 12 Aug 2025 19:04:41 GMT

Hi nabeela,

The reason the Thread-Wi-Fi switching feature is brought up is because the memory requirement for it is going to reflect Matter over Thread + Wi-Fi.

As mentioned, that alone consumes almost all of the nRF5340's flash memory. You will then have to add AWS on top of that,.

[quote user="nabeela"]Is that doable? Is it possible to do this with just modifying the necessary Kconfig, project config, and board config / overlay (using either the nRF7002DK which also has a 5340 on it, or the 5340DK with 7002EK). [/quote]

Without external flash, and without DFU: It is difficult and recommended against, because no DFU support doesn't make for a good product.

With external flash, with DFU: It is even more difficult, because the bootloader takes ~32kB or more. Furthermore, the memory required is so large that even if you can fit AWS in today, debug builds for development purposes will most likely be not possible, and future updates will be challenging. While not recommended against, still not recommended.

Without external flash, with DFU: No, that is entirely not possible.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

nabeela — Tue, 12 Aug 2025 15:42:14 GMT

So I just want to make clear that I don't need thread-wifi switching for Matter.

What I would like is the Matter Light Bulb sample project, which is currently Matter-WiFi + WiFi-AWS combo, if we can change that to be Matter-Thread + WiFi-AWS combo. So it's still matter, but running over Thread, and Wi-Fi is only used to communicate with AWS, not for Matter.

Is that doable? Is it possible to do this with just modifying the necessary Kconfig, project config, and board config / overlay (using either the nRF7002DK which also has a 5340 on it, or the 5340DK with 7002EK).

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Tue, 12 Aug 2025 08:17:16 GMT

Hi nabeela,

[quote user="nabeela"]Can we not make use of the external flash? such as XIP or something? or is the RAM itself is not sufficient?[/quote]

Will you not have DFU with your product? If you need DFU, you need external flash anyway.

XIP can help save some flash memory, yes, but only one image sector (in DFU context). That is not enough here.

Fitting things on RAM is going to be a challenge too, but as things are right now, fitting things on flash is a bigger challenge.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

nabeela — Mon, 11 Aug 2025 20:37:02 GMT

Hi - thanks for following up. Can we not make use of the external flash? such as XIP or something? or is the RAM itself is not sufficient?

in any case, thanks for the update.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Mon, 11 Aug 2025 19:52:55 GMT

Hi nabeela,

I checked with our developers today. The Thread-Wi-Fi switching feature is experimental, and the Lock sample almost use up the entire memory of the nRF5340. Using that as a benchmark, it's going to be very challenging to fit AWS support in. Thus, we don't recommend this.

If you attempt this, you can start with any Matter over Thread setup and add Wi-Fi to it following the AWS IoT sample.

We also recommend having the nRF70 Series firmware patches reside in the external memory and using Link Time Optimization.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Sat, 09 Aug 2025 22:07:10 GMT

Hi nabeela,

I wasn't aware of the Thread-Wi-Fi Switch feature showcased in the Matter: Lock sample.

I initially thought that the two stacks together would consume so much memory that it can't fit and planned to verify that. However, the existence of the Thread-Wi-Fi Switch feature obviously means that the two stacks can fit on the nRF5340 at the same time.

I have been studying this feature and the sample but have been unable to build the sample to test things out.
Looks like I will need some more time. My apology. I will follow-up in 1-2 business days.

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

nabeela — Fri, 08 Aug 2025 18:24:58 GMT

Thanks - to add a bit more context - if we can make the above Matter: Light Bulb sample work like the Matter: Lock sample where it allows Thread or WiFi switching for Matter -- but in any case keep WiFi for AWS working.

Matter: Door lock

RE: Matter Light bulb sample project modify for Matter over Thread keeping WiFi for AWS

Hieu — Wed, 06 Aug 2025 21:58:01 GMT

Hi nabeela,

I will look into this and follow up with you this week.

Hieu