Matter LightBulb - OnOff cluster on Endpoint 3

[oidebrett]

Hardware

Arduino Nano Matter

Core version

2.0.0

Arduino IDE version

2.3.2

Operating system

Windows 11

Radio stack variant

Matter

OpenThread Border Router device (if using Matter)

RPi

Issue description

Shouldnt the OnOff cluster be on Endpoint 1 not Endpoint 3 in the Matter light example?

Is there a reason why the OnOff cluster for the Matter light example is on endpoint 3 rather than endpoint 1?
see
libraries/Matter/examples/matter_lightbulb/matter_lightbulb.ino

I am testing with the chip-tool and after pair I am trying to interact with the OnOff cluster. In most other Matter development platforms that primary device type clusters are on endpoint 1. But i have found that any matter example that I have tried from this repo the primary clusters are on Endpoint 3.

Am I missing something?

Serial output

No response

RTT output (if using Matter)

No response

Minimal reproducer code

No response

[lboue]

@oidebrett
Maybe you can use SimplicityStudio as a workaround. The examples do not include a bridge. It works correctly in this case.

It works for Silicon Labs xG24 Explorer Kit but I am not sure it will work with Arduino Nano Matter board.

[silabs-bozont]

Hello @oidebrett,
This is by design - we use dynamic endpoints - so a bridge device was added on endpoint 2 to ensure compatibility with most ecosystems. Also, you can parametrize your chip-tool commands to look for the device on endpoint 3 and be able to interact.
Endpoint 1 is used by a placeholder endpoint which is disabled during startup.

[oidebrett]

Thanks for your reply. I am just starting my journey into Arduino nano matter development and I am using the Arduino IDE.

I have experience of using the ESp32 and I can write code using the Esp-idf to write code that implements endpoints, clusters etc.

Is there any documentation on how I could use the Arduino IDE to get a lower level of access to the matter data model and core functionality? For example if I don't want to use a bridge on endpoint 2 could I implement my own endpoints and clusters?

For example with ESP-idf I can use write code at this level

https://docs.espressif.com/projects/esp-matter/en/latest/esp32/developing.html#developing-your-product

Sorry to be asking this in the repo. Is there a better place to get this information that is regularly responded to?

Many thanks

[silabs-bozont]

Hello @oidebrett,

No worries, you're in the right place for asking questions. The bridge endpoint was introduced to ensure compatibility for the bridges/dynamic endpoints. In the future versions we'll introduce a way to turn it off, however in the meantime you can disable it with:
emberAfEndpointEnableDisable(emberAfEndpointFromIndex(1), false);

If you want to go a bit lower - take a look at the source of a device in the Matter library (like this and this) - those directly access the Matter SDK. You can create your own custom endpoints/devices in the same fashion.