How to extract json file

[ivangh24]

Hi everyone,

I'm working with a own device who acts like a provisioner in a bluetooth mesh net and with more devices acting like slaves devices (lights, switches, etc). Is it possible to extract the json file from the cdb on the device that acts as a provisioner via software? Is there an API for this? 

Regards, Ivan

[Joakim Jakobsen]

Hi.

Thank you for your interest in BLE Mesh and Nordic's solutions.

I'm working with a own device who acts like a provisioner in a bluetooth mesh net and with more devices acting like slaves devices

So this a provisioner based on an nRF device, not a smartphone i.e using the nRF Mesh app?

Could I ask you to also share which device, SDK version etc you are working with?

Br,
Joakim

[ivangh24]

Hi Joakim,

thanks for the answer. I'm working with the nrf52840 DK board on which I'm developing my own version of a provisioner device based on the example. I'm working with the latest version of nRF Connect SDK. Just to clarify, I'm aware of I can import/export the json file through nRF Mesh app but I want to know if it would be possible to export it with an API.

Best regards,

Ivan

[Joakim Jakobsen]

Thanks. 

There is no API for this as far as I know. 

The Mesh shell has some support for CDB if that is something that is interesting for your case. 

You can read more here: 

Mesh shell 

Configuration database

Br, 
Joakim

[ivangh24]

Hi again,

Now imagine that you have hundreds of nodes in an industrial installation and a master device that controls all of them and acts as the network provisioner and configurator. That master breaks down, for whatever reason. What is the best way to replace it so that it is the same as the other one and contains the cdb, all the network information and can communicate with all the nodes just like the previous one?

Thanks in advance,

Ivan

[Joakim Jakobsen]

Sorry about the delay. 

If the device is not read protected: 
Read the flash and settings storage: That would give you pretty much all the snapshot of key materials, sequence numbers, IV indices, etc. Once you have this data, you can transfer this to the new device via shell commands (or by custom methods).

If the device is read protected:
The device must periodically transfer CDB data to some gateway. This data can then be migrated to the new device via shell commands (or by custom methods). 

Once the new gateway has keys, it can query entire network one-by-one to restore its understanding of configuration of each node in the network.

Br, 
Joakim

[ivangh24]

Hi Joakim,

That sounds very good, although I have some doubts about how it works. So imagine you have this non-read-protected device but you can only read its memory once at the beginning of an installation. That means that normally the IV index will be 0 (normally) and, once the installation is created, that index will start to rise due to the exchange of messages. If we transmit the original data from the master to a new device, will it work? My understanding is that if its IV index is different from the network index, it will not be able to communicate.

If we have a device running in a network but, this device needs to be changed and moved to another installation but no message has been sent from the provisioner to reset the node within the mesh network. How can we communicate with it to reset it? What is the best way?

Thank you in advance. 

Ivan

[Joakim Jakobsen]

Hi.

You can read about the IV update procedure in the specification.

Also, there is quite some information about this here on devzone;

ie:   RE: IV Index and LPN devices that leave mesh

Br,
Joakim