nRF Cloud Bluetooth Quick Start

A production nRF Connect SDK (NCS) application for the nRF Connect for Desktop Quick Start guide. It is the peripheral_lbs sample (button/LED over Bluetooth® LE) with added Memfault observability: the device collects heartbeat metrics and coredumps and serves them over the Memfault Diagnostic Service (MDS) to a phone or desktop gateway, which uploads them to Memfault over HTTPS. The device itself performs no HTTP/TLS.

Supported board: nRF54L15 DK (nrf54l15dk/nrf54l15/cpuapp). This is the only supported target.

What the device does

Control	Behaviour
Button 0	LBS button characteristic - gateway/central sees the press (standard LBS).
Button 1	Demo crash - forces a fault (k_oops) to generate a Memfault coredump. Demo-only.
LED 0	Run status (1 Hz blink - firmware is alive).
LED 1	BLE connection status.
LED 2	LBS LED - controlled by the gateway/central (standard LBS).

Once a gateway connects and the link is secured, the device sends a heartbeat immediately, so it shows up in Memfault within seconds instead of waiting for the periodic interval.

Prerequisites

• The nRF Connect SDK toolchain matching this workspace's NCS base (currently v3.3.x - see the note under Bootstrap). Install it with the Toolchain Manager or nrfutil.
• nrfutil for flashing and reading the device ID.
• A Memfault account and a 32-character project key.

Bootstrap (T2 west workspace)

This repository is the top-level west manifest (T2 star topology). It imports sdk-nrf, which pulls Zephyr and all NCS modules.

west init -m https://github.com/nrfconnect/quickstart-bluetooth my-workspace
cd my-workspace
west update

Note - west version. Run west from the NCS toolchain environment (its west is recent enough for this manifest schema); a system west older than ~v1.2 will reject it. With the Toolchain Manager: nrfutil toolchain-manager launch --ncs-version v3.3.1 -- west update.

Build & flash

west build -b nrf54l15dk/nrf54l15/cpuapp --no-sysbuild project/app
west flash

The single zephyr.hex is the complete image - there is no MCUboot/sysbuild, no DFU (OTA is out of scope).

Provision the Memfault project key

The project key is set over the serial shell and applied on the next boot:

mflt set_project_key <your-32-char-project-key>
kernel reboot cold

mflt set_project_key persists the key, but it is read once at boot - the kernel reboot cold is required for it to take effect. To verify it:

mflt set_project_key
Project key: <your-32-char-project-key>

Security note. The key is stored unencrypted in settings storage (the same at-rest protection as baking it into flash). Runtime provisioning changes how the key arrives, not its confidentiality. For a hardened product, evaluate settings encryption / the nRF54L KMU / TF-M secure storage.

Set the advertising name

The BLE advertising name is set over the serial shell and applied on the next boot:

bt name <name>
kernel reboot cold

bt name <name> persists the name (settings key bt/name), but the advertising data is only rebuilt on the next kernel reboot cold. To verify it:

bt name
Bluetooth Local Name: <name>

This lets each device be given a distinct, recognizable name during onboarding (e.g. per-kit or per-desk), overriding the build-time default (CONFIG_BT_DEVICE_NAME, currently Quickstart_Bluetooth).

Use double quotes if the name has spaces, e.g. bt name "My Quickstart".

Find the device ID

The Memfault device serial is the FICR device ID. Read it from the PC:

nrfutil device device-info     # or: nrfutil device list

This lets support correlate a physical board with its Memfault device.

Try it end-to-end

1. Connect from a gateway. On mobile, use nRF Toolbox; on desktop, the nRF Connect for Desktop gateway. The link must be secured (paired) - MDS access is gated to the secured connection.
2. The device appears in Memfault within seconds with a reboot report.
3. Press Button 1 to force a crash. After the device reconnects, the gateway uploads the coredump.

Upload symbols for symbolication

Every build has a unique GNU Build ID. Upload the build's zephyr.elf to Memfault so coredumps and traces are symbolicated - without a matching ELF, Memfault shows "Unknown location".

# zephyr.elf is produced next to zephyr.hex in the build directory:
#   build/zephyr/zephyr.elf

Upload it via the Memfault web app (Software → Symbol Files) or the Memfault CLI. Re-upload on every firmware change; the Build ID changes each build.

Releasing

See RELEASE.md for the release process, versioning scheme, and cadence.