Custom BLE packets on mesh network

Question

Hello

I have a mesh node that needs to broadcast a custom BLE packet

To start advertising I call bt_le_adv_start and it works as expected.

I'm curious about the error that I see in the RTT log

00> [00:08:41.658,050] <dbg> bt_mesh_net: bt_mesh_net_relay: Relaying packet. TTL is now 9
00> [00:08:41.658,172] <err> bt_mesh_adv_legacy: Advertising failed: err -120

My understanding is that his is because my app started advertising and the mesh network cannot relay the packet

I tried to call

bt_mesh_relay_set(BT_MESH_FEATURE_DISABLED,BT_MESH_TRANSMIT(0,1));

before calling bt_le_adv_start but I get same error -120.

What's the proper way to disable mesh relay?

Is there a way for custom advertising and mesh relay to coexist in a provisioned mesh node?

Thank you

user77539 · Accepted Answer

OK, figured it out Turns out the TX thread stack size was too small for multiple advertising sets. Found a very cool trick that helped pinpoint the problem: CONFIG_RESET_ON_FATAL_ERROR=n By default the OS resets on fault so it's hard to figure out where the crash occurred. With reset disabled I saw the thread name in the log which happened to be "BT TX" So I looked at its stack size and found a setting to increase it CONFIG_BT_HCI_TX_STACK_SIZE=2048 did the trick