Accessing mesh relay data from the application layer in Zephyr

RE: Accessing mesh relay data from the application layer in Zephyr

AndyM — Fri, 29 Apr 2022 13:33:17 GMT

Update2

Set up publication and subscription to battery model - all succeeded

Battery client and server set up as above

Tried calling bt_mesh_battery_cli_get(batt_client,NULL,NULL) - get an error -125

Stumped. Please help

Thanks

RE: Accessing mesh relay data from the application layer in Zephyr

AndyM — Thu, 28 Apr 2022 22:00:40 GMT

Update

I added a battery model client and set up a handler but I'm still not getting any battery info on the receiving side

The client is instantiated as follows

struct bt_mesh_battery_cli _batt_client = BT_MESH_BATTERY_CLI_INIT(&batt_cli_handler);

struct bt_mesh_model root_models[] = {

BT_MESH_MODEL_CFG_SRV,

BT_MESH_MODEL_HEALTH_SRV(&_health_srv, &_health_pub),

//TODO: FW reporting. Possibly use level server?

// config and health clients needed for mesh shell,

BT_MESH_MODEL_BATTERY_SRV(&_batt_srv),

BT_MESH_MODEL_CFG_CLI(&_config_client),

BT_MESH_MODEL_BATTERY_CLI(&_batt_client),

};

static struct bt_mesh_elem elements[] = {

BT_MESH_ELEM(0, root_models, vnd_models),

};

I then provision the device and enable publish on the battery model.

mesh mod-pub 0x00ab 0x100c 0xC002 0 0 5 74 2 200

That succeeds and I see messages from my "get" opcode handler in the debug log

Then I provision a second device and subscribe to the battery server like so

mesh mod-sub-add 0x100 0xC002 0x100c

This also succeeds

I see that the messages arrive in the log (see below)

But my batt_cli_handler function is not called.

What am I missing?

Thanks

00> [00:03:55.746,795] <dbg> bt_mesh_net: bt_mesh_net_decode: 28 bytes: 689acc3f34f33bdb64a2426c9b21cf38aed1a8ff82ee42a7dd145947
00> [00:03:55.746,826] <dbg> bt_mesh_net_keys: bt_mesh_net_cred_find:
00> [00:03:55.746,826] <dbg> bt_mesh_net: net_decrypt: NID 0x68
00> [00:03:55.746,826] <dbg> bt_mesh_net: net_decrypt: IVI 0 net->iv_index 0x00000000
00> [00:03:55.746,856] <dbg> bt_mesh_net: net_decrypt: src 0x00ab
00> [00:03:55.746,948] <dbg> bt_mesh_net: bt_mesh_net_decode: Decryption successful. Payload len 24
00> [00:03:55.746,978] <dbg> bt_mesh_net: bt_mesh_net_decode: src 0x00ab dst 0xc002 ttl 5
00> [00:03:55.747,039] <dbg> bt_mesh_net: bt_mesh_net_decode: PDU: 68050000b400abc0026361ef25f1233a49acf4bcc8ad5865
00> [00:03:55.747,161] <dbg> bt_mesh_net: bt_mesh_net_relay: TTL 5 CTL 0 dst 0xc002
00> [00:03:55.747,192] <dbg> bt_mesh_net: bt_mesh_net_relay: Relaying packet. TTL is now 4

RE: Accessing mesh relay data from the application layer in Zephyr

AndyM — Wed, 27 Apr 2022 15:16:34 GMT

I see, thank you for help

RE: Accessing mesh relay data from the application layer in Zephyr

tesc — Wed, 27 Apr 2022 09:31:24 GMT

Hi,

No worries.

[quote user="AndyM"]My expectation is that if node A battery model is configured to publish to an address 123 and node B battery model is subscribed to receive messages from address 123, node B should receive a message from node A when it publishes it [/quote]

This is correct, given that:

The models are of correct types for the message (e.g. a battery server model publishing a Generic Battery Status message, and a battery client model receiving it.)
Both models are bound to the same application key (through configuration)

[quote user="AndyM"]how can this message be examined at the application layer? Is there an opcode handler that I need to implement?[/quote]

Please have a look at the API documentation for the Generic Battery Server and the Generic Battery Client libraries. For the server model, the state (i.e. the battery state) is kept in memory controlled by the application layer. For the client side, the call to bt_mesh_battery_cli_get() will either block (filling the provided memory with the response before it returns) or it will call a callback function (if said memory pointer is NULL).

Regards,
Terje

RE: Accessing mesh relay data from the application layer in Zephyr

AndyM — Tue, 26 Apr 2022 14:51:17 GMT

The former. The model that the message is addressed to, in this case a battery server model. It is configured to publish to a group address. My expectation is that if node A battery model is configured to publish to an address 123 and node B battery model is subscribed to receive messages from address 123, node B should receive a message from node A when it publishes it If that understanding is correct, how can this message be examined at the application layer? Is there an opcode handler that I need to implement? Sorry I'm still a newbie in mesh..Thank you

RE: Accessing mesh relay data from the application layer in Zephyr

tesc — Tue, 26 Apr 2022 12:24:37 GMT

Hi,

Are we talking about receiving data on the device and model that the message is addressed for, or are we talking about looking at the data on a Relay node in-between? On Relay nodes you cannot see messages that are not addressed to the node, and the messages are also often encrypted using an application key that is not present on the Relay node.

Regards,
Terje