BLE mesh: Using nRF52840 Dongle with sensor_server sample

[obr]

When evaluating BLE mesh with multiple nodes the nRF52840 Dongle is perfect to keep cost and physical size down.

I thus have one nrf52840 DK and a couple of nRF52840 Dongles. To get started I would like to get the "sensor_client" and "sensor_server" samples provided with the nRF Connect SDK working on these. I know that these samples are not marked as compatible with the dongle, but I assume this is more due to missing support then missing HW capabilities (?)

Anyhow both samples seems to work fine on the DK and can be detected and provisioned by the nRF Mesh app. But none of them appears in the nRF Mesh app when programmed to the dongle. I am using Visual Studio Code with nRF Connect SDK, choosing the dongle board in the build configuration and flashing the dongle with the nRF programmer over USB. I have also verified that the dongle works fine with the "blinky" and "console" samples. This includes getting the console output to a serial terminal over USB.

Since there is no debugger in the dongle it would be very useful to get console access to monitor how the application is performing and find out why the BLE samples doesn't work on the dongle. I thus combined the "console" and the "sensor_server" samples from the nRF Connect SDK to a new application. This also works fine on the nrf52840 DK, and can be detected and provisioned by the nrf Mesh app. And the console is appearing on the nRF USB connector on the DK as expected, but with multiple lines like "[00:00:28.142,150] <inf> usb_cdc_acm: Ring buffer full, drain buffer" mixed with the printk() output from the app during boot. I also get similar output (including the ring buffer full spamming) when running this application on the dongle, but it stops after the "Initializing..." output from the sensor_server part of the code.

I am using:
Windows 10
nRF Connect for Desktop v3.12.0
ncs toolchain v2.20
zephyr v 3.2.99
nRF52840 DK v3.0.0 2022.34
nRF52840 Dongle v2.1.1 2022.37

So there are two issues:

1) What is preventing the sensor_ samples from running on the dongle? This should be easily reproducible by building and flashing the samples out of the box to a dongle with no changes except choosing the correct board.

2) Any suggestions on how to get rid of the console spamming during boot with the new combined application? I have googled and tried some of the suggestions from others having similar issues, but to no avail.

[Elfving]

Hello Ove, and thank you for your patience.

So there are several things that can make it difficult to use the Dongle for development, as opposed to a development kit. One thing is flashing, that you can circumvent by essentially doing a DFU with the Programmer App. This takes advantage of the legacy nRF5 SDK bootloader that comes with the Dongle, that can swap one image with another. Though it doesn't really read the flash, nor delete it if that was something you would need to do.

The first issue you might run into then is getting the new image to fit into this old bootloader set-up. Here you have the bootloader in red, app in green, and MBR in yellow. NCS automatically know that you want to move the application up to 0x1000 when you build for the Dongle - though it doesn't know about the Bootloader placed on the top. Having the bootloader there is rarely a problem, unless you are planning on using that space for another partition. Which is what you are when running a Mesh sample, which needs a settings partition for provisioning.

app:
  address: 0x1000
  end_address: 0xf8000
  region: flash_primary
  size: 0xf7000
nrf5_mbr:
  address: 0x0
  end_address: 0x1000
  placement:
    after:
    - start
  region: flash_primary
  size: 0x1000
settings_storage:
  address: 0xf8000
  end_address: 0x100000
  placement:
    align:
      start: 0x1000
    before:
    - end
  region: flash_primary
  size: 0x8000
sram_primary:
  address: 0x20000000
  end_address: 0x20040000
  region: sram_primary
  size: 0x40000

The Mesh light sample genereates this partitions.yml file, which shows that it wants to place the settings partition at 0xf8000. We can overrule this by creating a 'pm_static.yml' which we move out of the build folder and into our project. We can here move our settings storage someplace else. 

app:
  address: 0x1000
  end_address: 0xD8000
  region: flash_primary
  size: 0xD7000
nrf5_mbr:
  address: 0x0
  end_address: 0x1000
  placement:
    after:
    - start
  region: flash_primary
  size: 0x1000
settings_storage:
  address: 0xD8000
  end_address: 0xE0000
  placement:
    align:
      start: 0x1000
    before:
    - end
  region: flash_primary
  size: 0x8000
legacy_bootloader_storage:
  address: 0xE0000
  end_address: 0x100000
  placement:
    align:
      start: 0x1000
    before:
    - end
  region: flash_primary
  size: 0x20000  
sram_primary:
  address: 0x20000000
  end_address: 0x20040000
  region: sram_primary
  size: 0x40000

Now it should be possible to run and provision the Mesh samples. Though before you do, remember that you can't delete anything using the DFU Flashing with the Programmer app. So, if you do want to re-provision the nodes, or if the node thinks that the data in the settings partition has gone bad, I don't think you will be able to do anything about it without using an external programmer. Or what you can do, is to somehow erase this data programmatically.

Regards,

Elfving

[obr]

Thanks Elfving , this works and the node on the Dongle can be provisioned now.

I did notice earlier that the settings ended up in the bootloader section and tried to change that in the \zephyr\boards\arm\nrf52840dongle_nrf52840\fstab-stock.dts, but that change didn't seem to get picked up by the build system (?).

I would like to keep the original partition settings when building for the DevKit. I thus tried to add the board name to the pm_static.yml filename as described in Configuring static partitions, but none of these are picked up (i.e. the partitions.yml file is back to default as without the pm_static.yml file) :

pm_static_pca10059.yml
pm_static_PCA10059.yml

Any suggestions on how to achieve this?

[obr]

For others wondering what board name to use in the pm_static.yml filename:
https://devzone.nordicsemi.com/f/nordic-q-a/96680/how-to-make-the-build-system-pick-up-pm_static_board-yml

[Elfving]

Hi Ove,

It seems I overlooked that last question of yours, sorry about that. I'm glad you got it figured out, even though you had to open a new ticket.

Regards,

Elfving

[obr]

No problem! Actually I think it is easier to find solutions in DevZone when there is one question per ticket. So I will prefer to ask non-related follow up questions in separate tickets from now on :-)

Regards,

Ove