Subscribe a group address for the Mesh Message

[ajay]

Currently, I am working with the Nordic SimpleOnOff Model of the Light switch in the Bluetooth Mesh.

I am good that the light in the mesh can be set on/off after Provisioned.

Now, i would like to divide the Board into 2 Groups, let's said Group A and Group B.

But i am not very sure how to work with that?

How can i drive a specify device to bind to a specific Group Address? I believe that i should subscribe to some service, but any sample code or pointer that can show how can I subscribe the service for that "group"?

After that, how should i send the message to "This Group" of light for On/Off.

I tried to study the code of access_model_publish, from the Mesh SDK, but seems it did not have a way to specify the Group address for boardcast.

And how about the Receiver? Should i define another set of OpCode, like SIMPLE_ON_OFF_OPCODE_GROUP_SET to do the operation there?

[ajay]

Some study here, may i confirm it is the correct approach?

It seems i need extend the two Nordic models for the device.

Simplie On/Off Model- it is many to handle the optcode for light On/Off, and may be if in case, can add on the intensity parameters for the control of the brightness.

Configuration Model- besides the existing feature that Nordic defined, i need to extend the model, such that it can handle about the Group setting of the Light, such that i can assign the Group ID to the specific device.

?? But I still not very clear, how to link the Group ID that i set above, to the Group address of the Nordic Mesh Arch?? This is some confusion for me yet...

Hope i can make my questions clear.

[ajay]

Can i have a pointer, which helper functions should be used to unsubscribe from the Model, when they are in that Group?

Or, should i do it in another way round?

[Hung Bui]

The group address (GROUP_ADDRESS = 0xCAFE) is assigned to the server in configuration phase.

You can find the assigning at PROV_STATE_CONFIG_SUBSCRIPTION event in do_config_step() in provisioner.c

If you want to assign different group address to different server, you can modify the code inside that event handler, and change the address.value there.

Another option is to change the subscription address locally on the server. To do that you follow what 's inside the configuration server on the server side handle_config_model_subscription_add().

Basically you need to call dsm_address_subscription_add() to add the group address to the DSM address database. And then call access_model_subscription_add() to assign the server model to listen to that address.

Similarly, when you want to broadcast to a group address or change between broadcast address, you do dsm_address_publish_add() to add the address to the database and then access_model_publish_address_set() to mount the address ID to the model. Check access_setup() in the client's code.

[ajay]

Thanks Bui, Your message help a lot

When walk along the code , i am a bit confusion about the

m_clients[GROUP_CLIENT_INDEX].model_handle vs m_group_handle in main.c

ERROR_CHECK(access_model_publish_address_set(m_clients[GROUP_CLIENT_INDEX].model_handle, m_group_handle));

It is found that when the data broadcast to the Group, by sending by the function simple_on_off_client_set_unreliable, it is using the model_handle instead the m_group_handle;

Have i mixed up something there?

So, in case when i have more than one group, I should still make use of the m_clients[GROUP_CLIENT_INDEX],

[Hung Bui]

Yes, but there are 4 clients on the client example (each one is one element ). 3 of them talk to the 3 servers and the last one talks to the group address. That's why you see m_clients[GROUP_CLIENT_INDEX].model_handle there.