Mesh Anchor , Node and Gateway Example for Nrf52832 dk and how to Approach mesh as beginner ?

[starkAbhi]

Hi,

i am using nrf connect extension in vs code with Zephyr OS build v3.2.99-ncs2 and Nrf connect SDK 2.3.0. Our Application requirement to make Mesh Network. In which Anchor, Node and gateway are placed to cover 2 rooms. 

could you please suggest me any example code and tutorials on this given diagram?

Regards Abhishek

[Hung Bui]

Hi Abhishek, 

Could you give some more information about your application ? 
What kind of data the node is collecting ? Would the node running on a battery or it's main supplied ? 
Would the anchor node in the range of each other or they can be out of range and would require the node(s) to relay message ? 

What's the distance between the Anchors ? And the distance between Gateway and Anchor. Would all the anchors be in the range of the Gateway ? 

Have you tried with our mesh sample in the SDK for example \nrf\samples\bluetooth\mesh\light and \nrf\samples\bluetooth\mesh\light_switch ? 

[starkAbhi]

Hi Hung Bui,

Hung Bui said:

Could you give some more information about your application ? 

Anchors are stationary wall mounted device operated on 3v-CR2032 Cell. nodes are also battery operated device. our application requirement to build mesh network of nodes to cover a range of room. each node sends their rssi value to the anchor. anchor collects the rssi value and send to the gateway. anchors would be in range to each other. Node relay rssi and address to the anchor periodically.

Hung Bui said:

What's the distance between the Anchors ? And the distance between Gateway and Anchor. Would all the anchors be in the range of the Gateway ? 

Distance between the Anchors: 15 - 20 meters. Distance between Gateway and Anchor : 10 - 15 meters. not all Anchors are in range of gateway. actually gateway has power source to run on full receive mode. we want what is standard range of ble devices. low energy max distance possible.

Hung Bui said:

Have you tried with our mesh sample in the SDK for example \nrf\samples\bluetooth\mesh\light and \nrf\samples\bluetooth\mesh\light_switch ? 

yes, currently using mesh example and provision them by nrf mesh network app. issue is that received rssi value is not of original sender. ow relay the rssi data? could please enlighten me on this? could not able to find meaningful tutorials and demo examples.  

Regards 

Abhishek

[Hung Bui]

Hi Abhishek, 

Please be aware that mesh relay node is not low power. Your Anchors won't be able to last for more than a few hours with the CR2032 if it does relay role. 

If you can connect the Anchor to main power supply then it's OK. 

As your end nodes doesn't need to do relay, they can be configured as low power nodes (no relay). This require the Anchor nodes to be in the range of other anchor nodes. 

Regarding your question about rssi. There isn't a standard model to collect the RSSI of the original node (I assume you want the RSSI of original node with the nearest neighbor node). You would need to implement your own RSSI server that collect the RSSI value of all nodes around it. The standard RSSI value in a mesh package only show the rssi of the last hop. 

[starkAbhi]

Hi Hung Bui,

Hung Bui said:

Please be aware that mesh relay node is not low power. Your Anchors won't be able to last for more than a few hours with the CR2032 if it does relay role. 

If you can connect the Anchor to main power supply then it's OK. 

Got it, Anchor should be on main power supply.

Hung Bui said:

As your end nodes doesn't need to do relay, they can be configured as low power nodes (no relay). This require the Anchor nodes to be in the range of other anchor nodes. 

Yes, Anchor nodes are in range.

Hung Bui said:

Regarding your question about rssi. There isn't a standard model to collect the RSSI of the original node (I assume you want the RSSI of original node with the nearest neighbor node). You would need to implement your own RSSI server that collect the RSSI value of all nodes around it. The standard RSSI value in a mesh package only show the rssi of the last hop. 

Yes, I discovered that rssi receive only last hope. how to make rssi collector server on mesh network? could you please share us some example code regarding custom server application?

how each nodes after provision know the address of anchor to send specifically their rssi to anchor only?

does anchor get status of all nodes in network and collect their rssi with address? 

[Hung Bui]

Hi Abhishek, 

There isn't a RSSI model example on nRF Connect SDK. However, you can have a look at our concept and implementation in nRF5 SDK (legacy SDK , no longer in development) https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.meshsdk.v5.0.0/md_models_vendor_rssi_monitor_doc_rssi_model.html?cp=9_2_2_4_5_2_0

The idea is that it collect the RSSI value of any mesh packet arrives. Then store it in a database. The client then can request that database from the server. 

starkAbhi said:

how each nodes after provision know the address of anchor to send specifically their rssi to anchor only?

The Anchor should request the RSSI database of the node. It can be that the only gateway can collect the RSSI value of each node in the whole network. 

I would suggest to get familiar with the mesh set up and how you can use the standard model, before you start implementing your RSSI model. 

[starkAbhi]

Hi Hung Bui,

Hung Bui said:

There isn't a RSSI model example on nRF Connect SDK. However, you can have a look at our concept and implementation in nRF5 SDK (legacy SDK , no longer in development) https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.meshsdk.v5.0.0/md_models_vendor_rssi_monitor_doc_rssi_model.html?cp=9_2_2_4_5_2_0

The idea is that it collect the RSSI value of any mesh packet arrives. Then store it in a database. The client then can request that database from the server. 

It is useful model. but as a beginner. i do not know where i  can start?

Hung Bui said:

The Anchor should request the RSSI database of the node. It can be that the only gateway can collect the RSSI value of each node in the whole network. 

did you mean Gateway request anchors for rssi of individual nodes. gateway(client-request rssi)->anchor(client-database rssi)(server-rssi)->nodes(server-rssi).?

or i am confused?

Hung Bui said:

I would suggest to get familiar with the mesh set up and how you can use the standard model, before you start implementing your RSSI model. 

where i can learn to implement models in mesh?

please provide some basic examples on mesh with context of my application.

Regard

Abhishek

[Hung Bui]

Hi Abhishek, 
As I mentioned, please get familiar with the mesh source code, try testing with the sample, how you can use model etc before moving to the real application of using rssi. 

You can run the rssi client on the gateway and then collect the rssi data of each of the node, In this case you collect data from Node 2, to see the RSSI between Node 1 and Node2. Then you collect data from Node 3 to see RSSI between Node 2 and Node 3. 
The Anchor only a relay device, it doesn't need to know anything about the nodes around it or which node is connected to it.

You can choose to do your own implementation, you can choose to have a database on the Anchor, but it's your design choice. We provide you the mesh network. The application, and how you design it is up to you.  

[starkAbhi]

Hi Hung Bui,

Agreed, i want to learn to work with mesh. I read about simple message model in mesh to send string of data from 1 node to another node. where can i get the example code to work with it? it's requirement of my Application to send string of data.

Regards

Abhishek

[Hung Bui]

Hi, 
Please try the mesh chat example. https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/mesh/chat/sample_description.html#

But my suggestion is to study the light and light switch example as well. The mesh chat example doesn't use a server. 
Also please study the mesh specification.