crowe-sense

Status: Firmware implemented and tested — 25 hardware-free unit tests pass (ruff clean). CI pipeline runs lint + tests + per-part STL renders. Enclosure is parametric OpenSCAD with a published BOM. Hardware bring-up validation is the remaining frontier.

Crowe Sensor — modular, 3D-printable environmental sensing node designed for remote / off-grid deployment. Built around a Raspberry Pi 5 compute core with dedicated, swappable bays for a 1 TB portable storage drive and an AT&T cellular Wi-Fi hotspot so the unit can log long horizons of telemetry and ship data home without relying on site Wi-Fi.

What's in this repo

crowe-sense/
├── docs/
│   ├── 01-system-architecture.md   System overview, block diagram, data flow
│   ├── 02-mechanical-design.md     Enclosure geometry, bays, tolerances
│   ├── 03-electronics-integration.md  Wiring, power, I2C bus, USB topology
│   ├── 04-firmware-architecture.md Pi-side services, storage, sync
│   └── 05-assembly-guide.md        Step-by-step build instructions
├── hardware/
│   ├── enclosure/
│   │   ├── crowe_sensor_enclosure.scad   Parametric OpenSCAD master
│   │   └── README.md                     Print settings & tolerances
│   ├── pinouts/sensor_pinout.md         GPIO/I2C/USB pin map
│   └── bom.csv                          Bill of materials
└── firmware/                             Pi-side Python services (implemented, 25 tests passing)

System at a glance

Subsystem	Component	Interface
Compute	Raspberry Pi 5 (8 GB)	—
Bulk storage	1 TB 2.5" portable USB drive	USB 3.0 (Pi)
Cellular backhaul	AT&T Nighthawk M6 / M6 Pro hotspot	USB-C tether / Wi-Fi
CO2 + T + RH	Sensirion SCD41	I2C @ 0x62
Precision T + RH	Sensirion SHT45	I2C @ 0x44
VOC + IAQ	Bosch BME688	I2C @ 0x76
Light	VEML7700	I2C @ 0x10
Optional vision	Pi Camera Module 3	CSI
Power	12 V DC in → buck to 5 V/5 A	barrel jack

Full bill of materials: hardware/bom.csv.

Why this design

The two "found components" — a 1 TB portable drive and an AT&T Wi-Fi hotspot — unlock two capabilities a typical IoT node lacks:

1. Local persistence at scale. The Pi can log raw sensor frames + camera stills + edge-inference results to the 1 TB drive for weeks to months without rotation. The drive lives in a dedicated, vibration-isolated bay that pops out for offload.
2. Backhaul independence. The Nighthawk lives in its own bay with antenna passthroughs and a USB-C tether to the Pi. The Pi treats it as primary uplink with automatic failover to site Wi-Fi if available.

Both bays are parametric — change three numbers at the top of crowe_sensor_enclosure.scad and the slot resizes for a different drive or a different hotspot model.

Quick start

1. Print the enclosure: hardware/enclosure/README.md
2. Source the BOM: hardware/bom.csv
3. Wire it up: docs/03-electronics-integration.md
4. Flash + provision: docs/05-assembly-guide.md

Open questions (please confirm)

• Exact 1 TB drive model and dimensions (we assume WD Elements 2.5" envelope).
• Exact AT&T hotspot model (we assume Nighthawk M6 / MR6500).
• Indoor lab or outdoor / weather-exposed deployment? Affects IP rating and the gland / vent specs in 02-mechanical-design.md.
• Camera in v1 or v2? Affects the front-panel cutout pattern.