Can I access the BLE mesh unicast address in my firmware after provisioning?

RE: Can I access the BLE mesh unicast address in my firmware after provisioning?

Julian1999 — Wed, 27 Aug 2025 10:13:32 GMT

Sorry, I need it because my network is always set up in a static way, like this:

Group 1:

Node 2

Node 3

Group 2:

Node 4

Node 5

...and so on.

If a node knows its own primary unicast address, it can also determine its group partner:

Even-numbered nodes know their partner is the next node.

Odd-numbered nodes know their partner is the previous node.

This way, they can communicate with each other, and when I use my phone app, I can address them through their group address.

RE: Can I access the BLE mesh unicast address in my firmware after provisioning?

Amanda Hsieh — Tue, 26 Aug 2025 19:39:48 GMT

comp->elem[0]->rt->addr will give the unicast address of the primary element, as suggested if node is provisined. It's still not clear why you need this. Could you elaborate on your use case?

RE: Can I access the BLE mesh unicast address in my firmware after provisioning?

Julian1999 — Tue, 26 Aug 2025 07:33:05 GMT

I noticed there are two different access.h files in NCS v3.1.0:

C:\ncs\v3.1.0\zephyr\subsys\bluetooth\mesh\access.h (the source file, ~121 lines, includes functions like bt_mesh_primary_addr())
C:\ncs\v3.1.0\zephyr\include\zephyr\bluetooth\mesh\access.h (the header that actually gets pulled in by #include <zephyr/bluetooth/mesh.h>, which is much larger but doesn’t include functions like bt_mesh_primary_addr()).

When I include Mesh in my project using:

it pulls in the access.h from zephyr/include/..., not the one from subsys/....

So my question is:

Do I need to include another header file explicitly to get access to functions like bt_mesh_primary_addr()?
Or is there a missing prj.conf setting that controls whether those APIs appear in the generated access.h?

RE: Can I access the BLE mesh unicast address in my firmware after provisioning?

Amanda Hsieh — Mon, 25 Aug 2025 17:27:16 GMT

The bt_mesh_primary_addr() is at

https://github.com/nrfconnect/sdk-zephyr/blob/ncs-v3.1.0/subsys/bluetooth/mesh/access.h#L56

https://github.com/nrfconnect/sdk-zephyr/blob/ncs-v3.1.0/subsys/bluetooth/mesh/access.c#L1140

RE: Can I access the BLE mesh unicast address in my firmware after provisioning?

Julian1999 — Mon, 25 Aug 2025 08:14:10 GMT

Hallo Amanda,

I'm talking about the primary unicast address.
After looking into the .c files, I found the following function: bt_mesh_primary_addr().
This function gives me the address, but for some reason it’s not present in access.h, even though it is in access.c.
Why is this the case?

Regards,
Julian L.

RE: Can I access the BLE mesh unicast address in my firmware after provisioning?

Amanda Hsieh — Thu, 21 Aug 2025 14:27:03 GMT

Hi,

Not sure why you need it. However, you can read out the unicast address of each element from here (after the node is provisioned): https://github.com/zephyrproject-rtos/zephyr/blob/main/include/zephyr/bluetooth/mesh/access.h#L158.

There is no unicast address of the node. Each element has its own unicast address. The address of the element with index zero is named the primary address.

Regards,
Amanda H.