how to send mesh messages from client to a specific server

Question

Hello, 
 I am using the light-switch example and I want to send a message or let say get the status of led of a particular server node....so how do I do that? 
 How to address them individually ..as the provisioner already assigns the addresses right 
 BR 
 Nakul

Bjørn Kvaale · Accepted Answer

You need to use the proxy client & proxy server examples. These two examples enable connection over smartphones via PB-GATT. Then, you can test the app by following a similar setup to the nrf mesh youtube video. Configure the proxy client & server nodes like shown in the video, but then instead of adding a group publication address in the client node, add the unicast address (e.g. 0006) for the server node instead. 
 There is a also small bug in the client_publication_configured(void) function in the proxy client example. 
 At the moment, the client_publication_configured function requires all four servers to be provisioned before you can publish a unicast or broadcast message. 
 By changing the function to this: 
 static bool client_publication_configured(uint32_t button_pressed)
{
 dsm_handle_t pub_addr_handle;

 if (access_model_publish_address_get(m_clients[button_pressed].model_handle, &pub_addr_handle) == NRF_SUCCESS)
 {
 if (pub_addr_handle == DSM_HANDLE_INVALID)
 {
 return false;
 }
 }
 else
 {
 return false;
 }
 return true;
} 
 it should work. Then, you should be able to press button 1 on the proxy client to toggle the LED of the proxy_server node. 
 It seems like the iOS device is setting a small connection interval & uses most of the timeslot for the mesh, leading to multiple calls to "Device is busy" on the proxy_client when pressing button 1 on the client. For now, you should be able to see quicker speeds if you disconnect from the mesh network on the nrf mesh app.

Nakul Nair · Answer

Hi arunbm123 , 
 According to my knowledge only the 1st 2 devices that get provisioned have unicast address then after it is divided into odd and even group. So we can send message to server 3 (which belongs to odd group so therefore we have to set the odd address in the simple_on_off_client_set() function ) but that message will also be relayed to other nodes in that group. 
 Probably you have to tweak the node_setup.c file in provisioner to change the addressing style if you want to send messages to a specific server.