RSSI value of Packet in Mesh

[hiteshk014]

Hi,

We need to read a RSSI value of received packet from nRF Mesh layer, have traced the RSSI of recieved packet in bt_mesh_msg_ctx structure -> recv_rssi;

checked in debug mode, verified in access layer when i debug the ctx of recieved packet we get RSSI value, TTL count and several other parameters present in bt_mesh_msg_ctx structure

Scenario observed: 

we've provisioned 2 devices(Device-1 & Device-2) in Mesh using nRF Mesh app & in device we're using nRF Connect SDK,

Scenario-1:

It is observed, Phone is connected to Device-1, I send the Packet from phone to Device-1, In Device-1 CTX->recv_rssi recieved is "0" 

Scenario-2:

 Phone is connected to Device-2, I send the packet of Device-1, Packet will travel from phone to Device-2 and then from Device-2 to Device-1 by reducing TTL count by 1, at Device-1 I'm able to read RSSI value of received packet when I get the packet which is hopped from other device in Mesh.

Query,

I'm able to get the exact RSSI value when packet is traveled from other device in mesh and received. but not able to get exact RSSI value of received packet in access layer when a packet is travelling from phone to device directly.

can you please suggest where do I refer in nRF Connect SDK to get a exact RSSI value of received packet when a packet is been sent out from phone to device after provisioning

Thank you,

Regards,

Hitesh

[Joakim Jakobsen]

Hi.

Thank you for your question.

Might be due to a limitation on the phone side, but I'll investigate. Could you also share which OS you are using on your phone?

Br,
Joakim

[hiteshk014]

Hi Joakin,

We've observed these observations in nRF Mesh app downloaded from Play store, Android 

Thank you,

Regards,

Hitesh

[Joakim Jakobsen]

Thanks.

I don't have an Android phone to reproduce at the moment, but I'll ask our developers about it.

Br,
Joakim

[hiteshk014]

Hi JoaKim,

Can you please expedite the solution for this problem

we're not able to get rssi value in ctx of recieved packet when it is sent out from mobile phone

Thank you,

Regards,

Hitesh

[hiteshk014]

Hi JoaKim,

Can you please expedite the solution for this problem

Thank you,

Regards,

Hitesh

[Joakim Jakobsen]

Hi. 

Sorry about the long delay in response. 

The controller doesn't provide such information for rx functions of gatt characteristics. Mesh doesn't have any sources to pick up this information. Proxy srv/cli always set rx rssi value to 0. 

As a solution you can register your own connection callback (BT_CONN_CB_DEFINE) to get the connection handle. Then you can call HCI command to read out RSSI value whenever you want to. 
You can take a look at this sample on how this can be done: https://github.com/zephyrproject-rtos/zephyr/blob/main/samples/bluetooth/hci_pwr_ctrl/src/main.c 

Also, you need to check the role in the connected callback (BT_CONN_ROLE_PERIPHERAL) and identity (BT_ID_DEFAULT) like we do here: 
https://github.com/zephyrproject-rtos/zephyr/blob/0e6c306dcec991311b11b4090430ade43d04777e/subsys/bluetooth/mesh/pb_gatt_srv.c#L102-L106 

I've talked to our developers, and currently there is no plans to add reading RSSI value in proxy messages. But this might change in the future. 

Br, 
Joakim