How many device can be connected in mesh light switch example.

[cyriactoms]

Hi,

I am working on mesh network. i need to control 10 nodes in the mesh network with having one main node. I have taken the light switch sample as an example.

The process which i created is like  in two development kits in one i flashed the light switch sample and in other i flashed light sample i configured with nrf mesh app and i am able to control the leds in light sample using the light switch sample.

Now i need to connect 10 light samples to this light switch which placed in within 40m radius (based on the bluetooth connectivity radius)

So while i send data from the mesh light switch dk the led which is 40m radius needs to blink by using mesh topology.

suppose i am having 4 development kits. in one dk i have flashed the light switch sample. the other three with light sample. and i have provisioned the nodes, since dk contains four switches i have assigned each switch for each light in different dk. now i have placed each light in different distance like one dk near the other and the last dk far from the ble radius of the dk having light switch sample. So when button is pressed the dk which is far away need to be blnked by mesh topolgy.

How this possible using the samples or is there any other samples which can be used.

i need to know the mesh communication range.

For Example suppose i have three mesh light sampled dk and one light switch sample. And i have kept each dk with light sample at 10m differnce from each.other So the dk with switch sample and the third dk with the light sample is having distance of 30m. Will it work through the mesh topology when data is send from the switch sample dk to the light sample dk which is placed at 30m distance.

[cyriactoms]

Hi,

Thanks for the valuable answer.

Since i have to send data to the third dk the message with pass through the first and second dk. So which dk will act as the Relay node in it ?.

For LPN

in the mesh circuit the friend node will be always connected to relay node and  the LP node will be connected to friend node is it correct?

so if i am implementing LPN one dk will be relay node one will be freind node and the last will be LPN.

[Amanda Hsieh]

Hi,

cyriactoms said:

Since i have to send data to the third dk the message with pass through the first and second dk. So which dk will act as the Relay node in it ?

The Relay node is responsible for receiving and forwarding messages to extend the range of the network.

If you have three DKs and want to send a message from the first to the third, you could configure the second DK to act as the Relay node. In this setup, when the first DK sends a message, the second DK (as the Relay node) receives and forwards the message to the third DK.

cyriactoms said:

For LPN

in the mesh circuit the friend node will be always connected to relay node and  the LP node will be connected to friend node is it correct?

so if i am implementing LPN one dk will be relay node one will be freind node and the last will be LPN.

LPNs primarily interact with the mesh network through a Friend node, which is responsible for relaying any messages directed to the LPN. The LPN saves power by keeping its radio turned off, and only wakes up to either send messages or poll the Friend node for the incoming messages. 

However, a Relay node can be beneficial in a mesh network as it extends the network range and allows messages to hop between multiple relay nodes, potentially improving the reliability and reach of the network. 

A Proxy node can enable communication between a Bluetooth Mesh network and devices that use the Bluetooth Low Energy GATT protocol, such as smartphones. If your application requires this functionality, it needs a Proxy node in your network.

So, the necessary nodes for an LPN in a Bluetooth Mesh network are primarily a Friend node, and optionally a Relay node or a Proxy node, depending on the specific requirements of your application.

See Bluetooth Mesh network topology and concepts

-Amanda H.

[cyriactoms]

Amanda Hsieh said:

configure the second DK to act as the Relay node.

Hi 

will it automatically act as relay node or should i need to add any configurations?

in prj.conf 

CONFIG_BT_MESH_RELAY=y    it is given like this. is this only enough or should i need to do any other configuration other than this .

Also i have doubt on friend node does the friend node needs a relay node to communicate or it can communicate directly in mesh.? if the mesh network only contains lpn nodes so the message will be relayed through friend node without the use of relay node.

what is the use of proxy and gatt bearer.?

[Amanda Hsieh]

cyriactoms said:

CONFIG_BT_MESH_RELAY=y    it is given like this. is this only enough or should i need to do any other configuration other than this .

That's correct. CONFIG_BT_MESH_RELAY can enable message relaying.

cyriactoms said:

does the friend node needs a relay node to communicate or it can communicate directly in mesh.?

A Friend node can communicate directly with LPNs without a Relay node. However, if a mesh network only contains LPNs, the messages will not be relayed through the network without the use of a Relay node. This is because LPNs are in sleep mode most of the time and cannot relay messages when they are asleep. Relay nodes are responsible for forwarding messages in the network, extending the range of the network, and allowing messages to hop between multiple relay nodes. Therefore, in a mesh network composed only of LPNs, a Relay node would be necessary to ensure that messages are relayed through the network. See Bluetooth Mesh network topology and concepts

cyriactoms said:

what is the use of proxy and gatt bearer.?

The Proxy node and GATT bearer allow Bluetooth LE devices that do not possess a Bluetooth mesh stack to interact with nodes in a mesh network. The Proxy node enables a legacy Bluetooth LE device to participate in the mesh network by establishing a GATT connection to a mesh device that has the proxy feature enabled. The GATT bearer is used for tunneling mesh messages over the Bluetooth LE GATT protocol. 

[cyriactoms]

Thank You for the valuable answers.   

[cyriactoms]

Is there any examples in nrf sdk to know how friend node , relay node, proxy node communicates other than light switch sample

[cyriactoms]

[00:02:31.869,659] <wrn> bt_mesh_friend: No free Friend contexts for new LPN

i got this message from friend node i have created. 

I need to connect atleast 6 LPN nodes to the friend node. What is to be configured to connect that much lpn to the friend node.

[Amanda Hsieh]

Check out CONFIG_BT_MESH_FRIEND_LPN_COUNT.