Mesh UUID

RE: Mesh UUID

Justin — Fri, 28 Sep 2018 21:45:48 GMT

i don't quite understand how the URI is supposed to be used. are there any examples?

it seems that the unprovisioned device beacons out a 4 byte hash of the URI.
how does the provisioner device use that?

in our BLE iot system, the central device just uses the peripheral device's MAC address in a query to a database to see if it should connect. we are looking to do a similar method with mesh. the MAC address is a simple choice, because it is a unique value per peripheral device.

RE: Mesh UUID

tesc — Mon, 17 Sep 2018 15:23:29 GMT

Hi,

I can confirm that the way the UUID is currently generated in the examples is not conformant to rfc4122.

Back to your use case, I got the suggestion from the team that you can use a name based UUID variant (see 4.3. Altorithm for Creating a Name-Based UUID in the rfc.) You should also consider other options, like the URI parameter in nrf_mesh_prov_listen() which is the way unprovisioned devices should be tied to their OOB identification.

Regards,
Terje

RE: Mesh UUID

tesc — Mon, 17 Sep 2018 08:20:01 GMT

Hi,

I have asked our mesh team to have a look into your questions, and will get back to you as soon as I have any answers.

Regards,
Terje

RE: Mesh UUID

Justin — Fri, 14 Sep 2018 17:43:28 GMT

it would seem that the UUID's generated in the mesh examples do not follow the format of rfc4122?
The version field is zero, which is not defined by rfc4122.

if we constructed UUIDs for our devices like:

yyyyxxxx-xxxx-1xxx-axxx-zzzzzzzzzzzz

where yyyy was our bluetooth mfg ID

where zzzzzzzzzzzz, was devices' unique BLE MAC address,

would that be a "problem"?

RE: Mesh UUID

tesc — Fri, 14 Sep 2018 14:29:05 GMT

Hi,

According to the Mesh Profile Specification, section 3.10.3 "Device UUID", the UUID must follow the format of rfc4122 and a generation procedure that ensures the uniqueness of each UUID.

The Device UUID is set in nrf_mesh_init(), which is invoked indirectly from the mesh application using mesh_stack_init().

Default value is made up of DEVICEID and DEVICEADDR, both of which are random (yet unique) values written to Factory information configuration registers (FICR) during production of the SoC. The reason for using those values for the default is that they are suited for the purpose.

You can override the default Device UUID by providing your own UUID value through the mesh_stack_init_params_t structure sent to mesh_stack_init(). E.g. create your own uint8_t[NRF_MESH_UUID_SIZE] containing the UUID and point init_params.core.p_uuid to it before the call to mesh_stack_init(&init_params, ...).

Regards,
Terje