HiveInside
A stand-alone, battery-powered in-hive environmental and acoustic sensor for
beehive monitoring. It broadcasts its readings over BLE as a beacon that the
HiveScale / HiveHub ecosystem picks up
with a passive scan each cycle and bridges to the backend.
- Target: Seeed XIAO nRF54LM20A Sense with an external SHT40, for low power and a
compact integrated sensor platform — its on-board 6-axis IMU (LSM6DS3TR-C),
PDM mic (MSM261DGT006) and nPM1300 PMIC fold most of the discrete sensors onto
the module. The firmware is a Zephyr application in
firmware-nrf54lm20a/, built with west and sysbuild.
[buy]
Part of the open beehive-monitoring ecosystem alongside HiveScale (weight /
external sensing) and BeeCounter (entrance traffic).
📖 HiveInside website — the
feature set, hardware and BLE payload on one page (source in
website/). The ecosystem hub is the
HiveHub site.
Why a separate device?
The frame-mounted accelerometer is, per the literature (Ramsey et al. 2020,
Sci. Rep.), the only reliable way to predict swarming up to ~30 days ahead —
microphones cannot capture the critical ~20 Hz vibrational signature. HiveInside
puts that accelerometer, plus acoustic FFT bands and climate sensing, inside
the hive on a tiny wireless board, avoiding the cabling a wired sensor needs.
Sensors
| Function | Part (XIAO nRF54LM20A Sense) | Interface |
|---|
| 3-axis vibration (swarm prediction, ~20 Hz) | LSM6DS3TR-C (on-board 6-axis IMU) | I²C |
| Acoustic FFT (piping, hum, stress) | MSM261DGT006 (on-board PDM mic) | PDM |
| Temperature + humidity | SHT40 (external) | I²C |
| Battery voltage + charge | nPM1300 PMIC fuel gauge (on-board) | — |
The firmware also auto-detects an external LIS3DH/LIS2DH12 at 0x18/0x19, so a
breakout-based bench setup runs the same pipeline as the on-board IMU.
Vibration and acoustics are analysed into the same FFT bands as HiveScale, so a
value means the same thing across the ecosystem.
Key features
- BLE beacon transport — the full measurement (climate, vibration +
acoustic FFT bands, battery) broadcasts continuously as a 29-byte
manufacturer-data advertisement that HiveHub decodes with a passive scan.
Reading the data needs no connection, pairing window, or wake-sync schedule.
- Per-node identity — each node advertises as
HiveInside-XXXX, where the
four hex digits are the last two bytes of its BLE address. Several nodes in
one yard are therefore distinguishable in a scanner and in HiveHub's dashboard
without any provisioning step; the suffix is derived from the address, so it
survives a factory erase and a firmware update.
- Ultra-low power — the nRF54 idles with only the ~1 s advertiser
running (a few µA); no deep-sleep rendezvous machinery required. The sensor
rail (IMU + microphone) is switched off between the five-minute measurements.
- Authenticated on-request audio (0.6.0+) — HiveHub can ask the node to
record from inside the hive; it streams raw 16 kHz PCM16 over BLE with a
60-second privacy cap, an HMAC-authenticated START, an end-to-end CRC and
(0.8.0+) an optional automatic recording level fixed per clip. The
microphone stays off until an authenticated request owns the link, and a
session can never overlap a measurement cycle or an OTA.
See
docs/audio-over-ble.md.
- Firmware-over-BLE (OTA) — implemented: MCUboot dual-slot with a small
GATT service that streams the signed image into the secondary slot, verifies
size + CRC-32, and test-swaps with automatic rollback. The device therefore
advertises connectable (
ADV_IND); the measurement payload itself is still
read passively from the advertisement.
See docs/ota-over-ble.md.
- Zephyr with sysbuild — one toolchain for everything.
west --sysbuild
builds MCUboot and the signed application together, which is what makes a
bootable image and an OTA payload; the repository ships a west.yml so the
workspace is reproducible. West with sysbuild is the only supported build
path; there is no parallel application tree or alternate build frontend.
Repository layout
HiveInside/
├── west.yml west manifest (pins the Zephyr revision to build against)
├── firmware-nrf54lm20a/ Zephyr application (XIAO nRF54LM20A Sense)
│ ├── prj.conf Zephyr config + app.overlay (board DT tweaks)
│ ├── low-power.conf deployment profile, layered on top (docs/low-power.md)
│ ├── sysbuild/ MCUboot child-image config for `west --sysbuild`
│ └── src/ main + sensor + FFT + beacon + OTA modules
├── enclosure/ Current 3D-printable enclosure files
├── tools/flash/ OpenOCD flashing scripts for the prebuilt release images
├── tools/release/ bootloader signing-key checker used by release CI
├── tools/throughput/ BLE throughput bench tool (pinned requirements.txt)
├── tests/host/ host regression tests (ASan/UBSan) for firmware modules
├── docs/ wiring, building, flashing, OTA, Home Assistant
├── CONTRIBUTING.md tests, versioning, release and branch policy
├── SECURITY.md how to report a vulnerability; security model
└── README.md
Quick start (XIAO nRF54LM20A Sense)
Just want a running node? Every
release ships prebuilt images:
a -factory.hex you flash over USB with the bundled flash.sh / flash.ps1
(OpenOCD, no toolchain), and a .signed.bin you push to an existing node over
the air through HiveHub. Pick the lowpower variant for a hive and bringup
for the bench. See
docs/flashing.md.
To build it yourself, set up a west workspace from this repository, then build
and flash:
west init -m https://github.com/MacNite/HiveInside hiveinside-workspace
cd hiveinside-workspace && west update
west build --sysbuild -b xiao_nrf54lm20a/nrf54lm20a/cpuapp -d debug hiveinside/firmware-nrf54lm20a
west flash -d debug
picocom -b 115200 /dev/ttyACM0 # serial console over the on-board debugger
--sysbuild is not optional: the firmware boots through MCUboot, so a bootable
device needs the bootloader and the signed application, and only a sysbuild
build produces both (plus the OTA payload). A plain west build yields an
application-only image with nothing at 0x0, which does not boot.
See docs/vscode-build.md to build it from VS Code or
VSCodium, docs/flashing.md for flashing details and
troubleshooting, and firmware-nrf54lm20a/README.md
for the readout format, BLE frame layout, and roadmap.
For the authenticated on-request PCM protocol, see docs/audio-over-ble.md.
For battery deployment, see the audited low-power build profile,
including measurement guidance and upstream references.
Status
🚧 Bring-up in progress; not yet hardware-validated in the field. The
firmware reads all four sensors (SHT40 climate, LSM6DS3TR-C acceleration, PDM
microphone level, nPM1300 battery), performs the vibration/acoustic FFTs, prints
the readout, and broadcasts the HiveHub-compatible BLE measurement beacon.
Active scans additionally receive its XIAO nRF54LM20A board identity and
firmware version without changing the measurement advertisement.
Firmware-over-BLE is implemented on top of MCUboot.
See firmware-nrf54lm20a/README.md for the
readout format and roadmap, and docs/wiring.md for the
XIAO and SHT40 connection reference.
License
MIT — see LICENSE.
