An advertisement data that contains manufacturing data

[SunHuang]

Hi 

As shown in the title, I want to add manufacturing data(BT_DATA_MANUFACTURER_DATA) to the advertisement data.

The *.conf seems to only define the device name...

I want to be able to  modify manufacturing data dynamically. 

let me know if anything I need to change, thanks!

OS: windows 10
Hardware used: nrf5340 dk
example:C:\ncs\v2.5.1\nrf\samples\matter\lock

[Edvin]

Hello,

After digging a while through the Matter advertising implementation, I see that it definitely has an impact on the advertising data. The reason the device name stays is that the Matter stack will use the device name as well. 

After talking to our Matter team, I got some info on how the BLE advertising part of the Matter stack works.

Basically, the Matter advertisements is it's own set. It doesn't matter what you put in your own advertising packets using the Bluetooth Stack directly. When you start advertising your Matter service, it will override whatever you were doing. If you want to keep your advertisements while using the Matter stack, you need to use it's API. The way that the Matter stack uses BLE advertisements is that it has several sets of advertisements, and it can only advertise one set at the time. The priority of the Matter advertising set is always the highest one. When it stops advertising with it's Matter set, it will then start with the next advertising set in the queue, with the highest priority. 

"It was designed in such a way, because the Matter advertising times out after 15 minutes, and sometimes the user may want to advertise longer or permanently (e.g. we do this in the NUS or DFU over BT SMP pusporses). It is not a problem that during the first 15 minutes we do not advertise NUS or SMP data, because the support for these services can be discovered using GATT discovery anyway.

The customer would need to modify modules\lib\matter\src\platform\Zephyr\BLEManagerImpl.cpp and add more data to the advertising data used during the Matter service advertising if they want to add custom data to the Matter service advertising set. In theory the advertising arbiter could try to combine the advertising data from N requests as long as they fit in 31 bytes, but we haven't done this so far."

So it is possible to add some custom data, but it is not straight forward. You can have a look at the BLEManagerImpl.cpp and see if you can fit any more custom data without overflowing the 31 byte limit. I think PrepareAdvertisingRequest() is the place to start. If that doesn't work, you will need to use a different advertising set, but you will not be able to use this at the same time as you are advertising your Matter service. 

Best regards,

Edvin

[SunHuang]

Hi Edvin

I can understand your reply, but I'm not sure that PrepareAdvertisingRequest()  is allowed to be modified.

[Edvin]

As I see it, you have two options.

1: Advertise with your custom data only whenever you are not advertising your Matter services (so when your Matter service advertising data times out, or stops due to another reason, like a connection or something).

2: Modify modules\lib\matter\src\platform\Zephyr\BLEmanagerImpl.cpp and add more data to the advertising data used during the Matter service advertising. 

These are the two options that our Matter team provided. 

If neither of these are suitable, you would need to implement something that alternates advertising with the Matter service and your custom advertisements. You can look at the ncs\nrf\samples\bluetooth\multiple_adv_sets for reference. However I am not sure exactly how to do that, since the advertising of the matter stack seems to be quite far down in the stack, so it will be difficult to do without changing anything in the Matter files.

Best regards,
Edvin

[SunHuang]

Hi Edvin

thank you for your information, I used option 1 and sure it works.

In addition, I expect that the BLE peripheral(nus) can connect to multiple devices at any point in time.

But when I restarted the Advertising, it failed.

example:C:\ncs\v2.5.1\nrf\samples\matter\lock

[SunHuang]

The problem has been solved. If there is any mistake in my method, please tell me.

Just add CONFIG_BT_MAX_CONN in multiprotocol_rpmsg and set the value to 2.

The device advertises after I connect to the device.