Bluetooth Mesh - relaying?

[slowhand]

Hi,

I have couple of nRF52832 boards, nRF5-SDK-for-Mesh (v. 0.9.2) and good will to demonstrate some simple multihop mesh.

I already tested the light control example, and saw it working with one client and 3 servers while they were all on my desk and all the 3 servers within the client's range.

However, to make multihop (at least two) ... do you have any tips if can I demontrate relaying/multihop with these example codes somehow?

Slowhand

[Danny Wahlquist]

I set up multiple sets of the Light control demo and then used a single client to command all the servers. I then could verify that physically remote devices did not turn their LEDs on or off without intermediate devices relaying the messages.

[slowhand]

Ok. Now I tried something similar(?) with 4 devices: I moved the client from my desk to a separate room nearby and one of the three servers to another room in another direction. Scanning with nRFConnect on my desk I could still see all the devices, but scanning in the room of the client I could not see the distant server. So I thought it is 2 hops from the client to the distant server. I even got the led on in the distant board (once, but not anymore later).

BUT, I think the antenna is better in nRF52832 than in my Honor8 (with nRFConnect). So, I can't be sure if there was really two hops or if the client was able to command the distant server directly.

How to monitor what really happens?!

[bjorn-spockeli]

You could lower the TX power of the devices by calling sd_ble_gap_tx_power_set() after mesh_core_setup() so that you do now have to place the nodes so far apart. You should be able to access the TTL value of packets that are received by accessing the ttl member of the access_message_rx_t struct that is passed by callbacks, e.g. rx_set_cb in the server example and rx_status_cb in the client example