Procedures for integrating nRF Cloud into a Bluetooth Mesh Project

[a.da]

Hello.

I am currently testing nRF Cloud and encountering an issue.
I encountered a build error when merging the Peripheral Memfault Diagnostic Service (MDS) sample program into my existing Bluetooth Mesh project.

In file included from C:/ncs/v3.2.1/modules/lib/memfault-firmware-sdk/ports/zephyr/common/metrics/memfault_platform_bluetooth_metrics.c:17:
C:/ncs/v3.2.1/zephyr/subsys/bluetooth/controller/ll_sw/lll.h:95:37: error: 'CONFIG_BT_CTLR_SCAN_AUX_SET' undeclared here (not in a function); did you mean 'CONFIG_BT_CTLR_ADV_SET'?
   95 |                                    (CONFIG_BT_CTLR_SCAN_AUX_SET) - 1),
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                     CONFIG_BT_CTLR_ADV_SET

C:\ncs\v3.2.1\zephyr\subsys\bluetooth\controller\ll_sw\lll.h

#if defined(CONFIG_BT_OBSERVER)
	TICKER_ID_SCAN_STOP,
	TICKER_ID_SCAN_BASE,
	TICKER_ID_SCAN_LAST = ((TICKER_ID_SCAN_BASE) + (BT_CTLR_SCAN_SET) - 1),
#if defined(CONFIG_BT_CTLR_ADV_EXT)
#if defined(CONFIG_BT_CTLR_SCAN_AUX_USE_CHAINS)
	TICKER_ID_SCAN_AUX,
#else /* !CONFIG_BT_CTLR_SCAN_AUX_USE_CHAINS */
	TICKER_ID_SCAN_AUX_BASE,
	TICKER_ID_SCAN_AUX_LAST = ((TICKER_ID_SCAN_AUX_BASE) +
				   (CONFIG_BT_CTLR_SCAN_AUX_SET) - 1),
#endif /* !CONFIG_BT_CTLR_SCAN_AUX_USE_CHAINS */

To investigate, I tried the opposite approach: adding only the required Bluetooth Mesh configurations to the MDS sample program.
However, this resulted in the exact same error.
Added settings:

CONFIG_BT_OBSERVER=y
CONFIG_BT_EXT_ADV=y
CONFIG_BT_CTLR_ADV_EXT=y

The source of the conflict is as follow:
To enable Mesh, it is necessary to enable CONFIG_BT_OBSERVER, CONFIG_BT_EXT_ADV, and CONFIG_BT_CTLR_ADV_EXT.
When these are enabled, CONFIG_BT_LL_SW_SPLIT becomes a mandatory requirement.
( Specifically, both CONFIG_BT_CTLR_SCAN_AUX_USE_CHAINS and CONFIG_BT_CTLR_SCAN_AUX_SET depend on CONFIG_BT_LL_SW_SPLIT is enabled. )

Is it possible to integrate nRF Cloud without enabling CONFIG_BT_LL_SW_SPLIT?
According to the Kconfig search, CONFIG_BT_LL_SW_SPLIT is marked [EXPERIMENTAL] feature.
Unless there is a specific or mandatory reason for its use, I would like to avoid enabling it to ensure project stability.

a.da

[Edvin]

Hello,

I think you sidetracked a bit. Did you use CONFIG_BT_LL_SW_SPLIT=y before you started adding the Memfault Service?

The CONFIG_BT_LL_SW_SPLIT=y basically says that you use the Zephyr Bluetooth Controller instead of Nordic Semiconductor's Bluetooth Stack (the SoftDevice Controller).

Also, can you please describe a bit how you plan that this should work? You have a Bluetooth Mesh network, and you want to add the Memfault Service. This will not automatically make every device report this to some gateway. It will add a Bluetooth Low Energy Service that stores the crash faults to some flash partition, but it is only useable for devices that are connected to a Mobile device via Bluetooth Low Energy (not through Bluetooth Mesh). 

I am not sure, it might work the way that you have planned out, but can you please give some description on how you planned that this will work, and how it should behave? And what features you intend to use from the Memfault Service?

Best regards,

Edvin

[a.da]

Hi Edvin, thanks for your reply.

Edvin said:

Did you use CONFIG_BT_LL_SW_SPLIT=y before you started adding the Memfault Service?

No, I have never used 'CONFIG_BT_LL_SW_SPLIT=y'.
I am using the Nordic Semiconductor's Bluetooth Stack.

I apologize for the confusion.
My intention is not that I want to use the Zephyr Bluetooth controller; rather, I want to confirm if it is mandatory to enable it for this integration.
As I mentioned, enabling Mesh-related configs seems to force this dependency, and I am trying to find a way to avoid it.

Edvin said:

Also, can you please describe a bit how you plan that this should work?

To provide some context, I am relatively new to the Memfault Service and am currently in the exploration phase to see how it can be utilized within my Bluetooth Mesh project.
I understand that in order to register a device and upload reports to Memfault Service, a direct BLE connection to a mobile device is required.
Of course, it is not practical for a Provisioner or gateway to maintain a constant connection with every node in a Mesh network.

Therefore, I am still considering what kind of data to store and how to manage the reporting process, including how it would operate in a real-world market deployment.

At this stage, I anticipate that the OTA Releases feature, in particular, will be partially applicable to my needs.

a.da

[Edvin]

I understand. You should not need to use CONFIG_BT_LL_SW_SPLIT=y for any of the Bluetooth Mesh features either.

Let me check with the Memfault team whether they already have anything for Bluetooth Mesh, or any thoughts on how we can attack that. Particularly around OTA, but also with regards to fault data reports. 

Please excuse the delay, but I need to discuss this internally first. I will get back to you once I know more, or perhaps the Memfault team will handle this ticket directly. 

Best regards,

Edvin

[a.da]

Hi Edvin,

Thank you for looking into this and for coordinating with the Memfault team.
I look forward to hearing more from you or the team.

a.da

[Edvin]

Hello,

Unfortunately, we don't provide the Memfault service over Bluetooth Mesh at this point in time. 

It is probably still possible to add the memfault service as a BLE service (but you would need to connect to the device via Bluetooth (not mesh) to use it.

I assume this is what you tried originally. Would it be possible to upload the project where you tried to add the memfault service? And what was it that you added that caused it to fail?

Best regards,

Edvin

[a.da]

Hi Edvin,

Edvin said:

Unfortunately, we don't provide the Memfault service over Bluetooth Mesh at this point in time. 

It is probably still possible to add the memfault service as a BLE service (but you would need to connect to the device via Bluetooth (not mesh) to use it.

Yes, I understand.

Edvin said:

I assume this is what you tried originally. Would it be possible to upload the project where you tried to add the memfault service? And what was it that you added that caused it to fail?

Instead of my actual project, I am attaching a sample program that reproduces the exact same build error.
I would like to keep this ticket public so that it remains accessible to others, and the issue is easily reproducible using this sample.

light_ctrl.zip

Specifically, I merged the 'prj.conf' from the MDS sample into the 'prj.conf' of the Lightness Controller sample.
Please note that I have omitted the Memfault Project Key.

Best regards,

a.da