Trenz mounted

Groundlark — open hardware for seismic and environmental monitoring

Groundlark is a family of hardware boards and companion software for seismic and environmental monitoring. Each board has its own hardware directory, with shared component libraries, interfaces and validation tools.

The family has three products: the Groundlark FPGA HAT, Skylark and Burrowlark USB sensor heads. All share the sensor contracts, simulation tools and local workbench.

Groundlark

Seismic monitoring on a Raspberry Pi. The active Groundlark FPGA HAT, model DAQHAT-01, is a 140 × 56 mm, six-layer FR-4 board with three XYZ LSM6DSO IMUs and an ADS122C04 input for an external Racotech geophone, plus a fitted SDP32-125PA infrasound sensor and u-blox MAX-M10S GNSS with a side-facing SMA antenna connector. The stack is Pi → HAT → Trenz Artix-7 200T FPGA. Pi acquisition works independently of a configured FPGA.

The internal FPGA link provides six QSPI wires, UART, reset and switched Pi-driven JTAG. An SPI echo bitstream is implemented; accelerated sensor processing and native quad transfers remain future work. The FPGA uses a separate Nexys Video-compatible 12 V, center-positive adapter through J83 and an onboard 3.326 V converter. See the power limits.

Status: active prototype. Physical power, fit, timing, noise and thermal qualification remain pending. See the stack assembly guide, JLCPCB instructions and bench procedure. The JLCPCB package targets one assembled HAT; sourcing, placement and J1 fit checks remain open. Fabrication packages stay local in ignored hw/releases/.

R3 prototype enclosure, current 140 mm HAT CAD with GNSS/SMA, infrasound, TI Pi supervision and independent FPGA power, vendor Trenz components and a detailed Pi 4B model by integrated-circuit / FreeCAD community (CC BY 3.0). Clear PETG appearance, risers, geophone and wiring are approximate. Physical fit remains unqualified. Render provenance.

Closed enclosure render provenance. Measured gain/offset workflows and PCB probe access are in the calibration guide. Seismic recordings support local miniSEED export.

Skylark

Outdoor air-quality monitoring over USB. Skylark USB combines a vertical 90 × 100 mm PCB with a removable sensor tray and a 130 × 94 × 185 mm bell enclosure.

• Particles: Plantower PMS5003, with separate downward-facing inlet and exhaust paths.
• Gases: socketed SGX-7SO2-AQ-20 sulfur dioxide and SGX-7H2S-AQ-25 hydrogen sulfide cells.
• Weather: SHT40 temperature/humidity and BMP390 barometric pressure.
• Connection: USB-C power and data through an STM32F072 microcontroller.
• Housing: printable bell, rear M4 keyhole mounts and a removable tray with separate PMS cradle and splash cover. Bottom ventilation is sheltered by a 25 mm skirt.

Prototype firmware implements sensor acquisition and USB streaming. The shared workbench includes Skylark simulation, recording/replay, board-specific tests and an interactive 3D PCB. Gas data retains separate raw working and auxiliary electrode counts; concentrations require calibration.

Status: Rev A PCB, Rev G enclosure and prototype firmware are implemented. Physical fit, USB power behavior, analog performance, gas response and weather resistance still require qualification. The ventilated enclosure has no assigned IP rating. Follow the PCB guide and enclosure assembly instructions.

Render: native PCB artwork and authored component models in the CAD-derived tray, with the bell set beside it. Component bodies are dimension envelopes; fasteners and cable dressing are illustrative. Render provenance.

Burrowlark

Remote magnetic and enclosure-climate sensing over USB. Burrowlark USB, model DAQUSB-01, carries four RM3100 magnetometers on a 30 mm square grid and an SHT45 temperature/humidity sensor. One STM32F042K6 coordinates their measurements and sends each sensor's raw data and timing evidence to the Pi over USB-C. The SDP32-125PA infrasound sensor is fitted on Groundlark DAQHAT-01.

Status: routed prototype hardware, MCU firmware and workbench simulation are implemented. Physical USB, synchronization, magnetic cross-talk and noise qualification remain pending. See the USB sensor-head guide for interfaces and assembly details.

Render: native 96 × 70 mm PCB with favicon, Burrowlark name and DAQUSB-01 / REV B1 silkscreen, four RM3100 modules and SHT45 U6/C10; the former infrasound footprint and bypass capacitor are removed. Module, fuse and SHT45 bodies are simplified dimensional envelopes. Render provenance.

Sensor workbench

The dark-mode Python UI lets you switch between Groundlark, Skylark and Burrowlark, with interactive 3D views, raw-data charts, stimulus/fault controls, board-specific tests and recording/replay. No hardware or Docker is required. Follow the beginner walkthrough to create your first signal.

# Windows: set up once, then launch
./setup-ui.ps1 -Check
./ui.ps1

On Linux/macOS, use sh ./setup-ui.sh --check, then sh ./ui.sh. Open http://127.0.0.1:8080. Tools and dependencies stay in ignored .local/.

This is an actual browser screenshot with simulated data. Select the geophone can or its HAT input to highlight both and inspect the same ADC stream. Use the Board selector for the FPGA HAT, Burrowlark or Skylark. Test selected board runs the selected board’s checks; the HAT test covers all six sensors over eight simulated seconds. IMU, ADC and GNSS use production Pi drivers on modeled buses; infrasound uses a raw-response model pending its Pi driver. Signal checks and recordings/results are downloadable. The Groundlark GNSS panel also models disconnected or shorted antennas, lock loss and recovery, and PPS loss independently. The UI simulates and replays; physical acquisition uses the Pi software. Live seismic capture stores raw geophone and IMU counts locally as miniSEED 3, with SSREC companions for diagnostics and replay.

Project files and tests

For the full test environment, run ./lab.ps1 build once, then ./lab.ps1 test. Use ./lab.ps1 test -Profile software for sensor contracts, acquisition, recording/replay and recovery. Use ./lab.ps1 test -Profile simulation for fresh circuit builds, CAD checks and all models while excluding the procurement release gate. See the simulation scope and portable lab guide for Linux commands, test scope, five-run retention and cleanup.

Hardware sources: DAQHAT-01 circuit, KiCad PCB, Burrowlark DAQUSB-01, and Skylark USB. See build instructions and source references.

License

Project-authored code, hardware designs and documentation use the MIT License. Third-party assets and dependencies retain their own licenses and attribution.