Bluetooth mesh on nRF52840 SDK vs Zephyr

[kratenko]

Hi everyone,

I am doing an evaluation for a Bluetooth Mesh based project. There is however one huge source of uncertainty that I cannot find definitive answers to, and that is caused by the two currently existing solutions for programming nordic SOCs. Traditionally there used to by the mesh-SDK using the Softdevices that provide a well tested solution. But nordic is changing everything towards zephyr atm. The nRF52 chipsets seem only half ported to me, and all my research gives me mixed answers, depending on which solution is used. I found some information to parts of my questions, but they seem to contradict (e.g. if zephyr supports BT-LongRange).

In order to give solid advice on the usage of the nRF52480 I came up with a few questions:

1. Does Zephyr use the Softdevices for the nRF52480 in any way? Are there plans to do so in the future?
2. If I start a new BT-Mesh project, should I go with the well tested mesh-SDK (which seems end-of-life) or with the coming thing Zephyr (which seems not production ready, yet). Is there any recommendation by Nordic?
3. Does Zephyr support BT-Longrange (Coded Phy)
4. Is it realistic to try and build BT-Mesh using Coded Phy in Zephyr (I know that is outside of the Mesh spec. I also know that it has been done with the SDK)
5. Is it possible to use the Mesh-SDK without Segger-IDE (all howtos start with "install segger ide")

Using the BT-Stack from Zephyr does not give me the same confidence as the Softdevices give. Also Certification seems like an issue when using Zephyr compared to using the Softdevices.

Any answer to those questions would be really appreciated, as without that information I feel hesitant to recommend using either solution.

Thanks

[Hung Bui]

Hi Kratenko, 

I will need to check with the mesh team to get a confirmation regarding long range with mesh on NCS. But as you already mentioned, it's not covered in the mesh spec. So this feature will not on the top of our priority and will not have any official support unless there is a change in the spec. 

Regarding your question:

1. Does Zephyr use the Softdevices for the nRF52480 in any way? Are there plans to do so in the future?  No, Zephyr doesn't use softdevice. Zephyr has its own host stack and its own controller stack. In our NCS SDK (which partly uses Zephyr but it's not the same as Zephyr) we provide in addition a Nordic's controller which based on the softdevice. But it's only the controller stack. 
2. If I start a new BT-Mesh project, should I go with the well tested mesh-SDK (which seems end-of-life) or with the coming thing Zephyr (which seems not production ready, yet). Is there any recommendation by Nordic?
   I would suggest you discuss this with our RSM for Germany to find the best solution for you. Please let me know if you don't have the contact. Our generic advise currently is that if you are fine with what available now in nRF Mesh SDK and would go to production phase fairly soon you should go for NRF5 SDK. If you are only evaluating and may need advanced feature that new Bluetooth Mesh spec may have then you should get started with NCS Mesh.  
3. Does Zephyr support BT-Longrange (Coded Phy). Yes, at least for BLE. I don't have the confirmation for LongRange with Mesh ( and don't think there will be, as it's out of spec)
4. Is it realistic to try and build BT-Mesh using Coded Phy in Zephyr (I know that is outside of the Mesh spec. I also know that it has been done with the SDK)
   I believe it's possible but I can't confirm. 
5. Is it possible to use the Mesh-SDK without Segger-IDE (all howtos start with "install segger ide") 
   Yes, you can compile using ninja in command line. Have a look here.

It's pretty early for Mesh and even Bluetooth on Zephyr/NCS but we are doing certification and in a short future time frame (6 months) there will be official support and certification for Bluetooth and probably Bluetooth Mesh as well. 

[kratenko]

Hi Hung, thanks for the elaborate answers. This should be sufficient for an evaluation I think. Cheers.