project-structure.md

📁 Project Structure

bme280/
├── bme280.py               # I²C driver — Bosch calibration algorithms
├── sensor_api.py           # Flask HTTP API + MQTT publisher
│
├── tests/
│   ├── test_bme280.py      # Driver unit tests (hardware mocked)
│   └── test_api.py         # API route tests (Flask test client)
│
├── docs/
│   ├── hardware.md         # Components, wiring, I²C address
│   ├── architecture.md     # System diagram, component descriptions
│   ├── installation.md     # Prerequisites, clone, configure
│   ├── configuration.md    # Full environment variable reference
│   ├── usage.md            # CLI, HTTP API, cron, Docker
│   ├── api-reference.md    # Endpoint documentation with examples
│   ├── home-assistant.md   # MQTT auto-discovery, HA integration
│   ├── development.md      # Test suite, lint, CI pipeline
│   └── project-structure.md
│
├── .github/
│   └── workflows/
│       └── ci.yml          # CI: lint, test, security (pip-audit)
│
├── Dockerfile              # Multi-stage: test target + app target
├── docker-compose.yml      # Services: test, app
│
├── .env.example            # Configuration template
├── requirements.txt        # Runtime dependencies
├── requirements-dev.txt    # Dev/test dependencies
├── pytest.ini              # Pytest configuration
└── .gitignore

Key dependencies

Package	Version	Role
smbus2	>= 0.4.3	I²C communication via /dev/i2c-*
flask	>= 3.0.0	HTTP API framework
paho-mqtt	>= 1.6.1	MQTT client (fire-and-forget publish)
python-dotenv	>= 1.0.0	.env file loading at startup

Dev/test only:

Package	Version	Role
pytest	>= 8.0.0	Test runner
pytest-flask	>= 1.3.0	Flask test client fixture
flake8	>= 7.0.0	Style linter (PEP 8, max line 120)
mypy	>= 1.0.0	Static type checker

Sensor Specifications

Measurement	Range	Resolution	Accuracy
Temperature	-40 °C to +85 °C	0.01 °C	+/- 1 °C
Humidity	0 to 100 %RH	0.008 %RH	+/- 3 %RH
Pressure	300 to 1100 hPa	0.008 hPa	+/- 0.0018 hPa

BME280 datasheet