ha-enviro-plus

Enviro+ → Home Assistant MQTT Agent A lightweight Python agent for publishing Pimoroni Enviro+ sensor data (temperature, humidity, pressure, light, gas, and system metrics) to Home Assistant via MQTT with automatic discovery.

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🚀 Overview

ha-enviro-plus turns a Raspberry Pi Zero 2 W (or any Pi running the Enviro+) into a self-contained Home Assistant satellite.

It reads data from:

• BME280 (temperature, humidity, pressure)
• LTR559 (ambient light)
• Gas sensor (oxidising, reducing, NH₃) and publishes them to Home Assistant over MQTT using native HA Discovery.

Additional system telemetry is included:

• CPU temperature, load, and uptime
• Memory and disk utilisation
• Network info and hostname
• Service availability and reboot/restart controls

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🧩 Features

• Plug-and-play Home Assistant discovery (no YAML setup)
• Fast, configurable polling (default 2 s)
• On-device temperature / humidity calibration offsets
• CPU temperature compensation for accurate readings (higher number lowers temp. output)
• Host metrics: uptime, CPU temp, load, RAM, disk
• MQTT availability and discovery payloads
• Home Assistant controls:
  • Reboot device
  • Restart service
  • Shutdown
  • Apply calibration offsets
  • Adjust CPU temperature compensation factor
• Structured logging (rotation-friendly)
• Graceful shutdown handling (SIGTERM/SIGINT)
• Startup configuration validation
• Safe installer/uninstaller with config preservation
• Versioned installation support (--release, --branch flags)
• Designed and tested with a Raspberry Pi Zero 2 W + Enviro+ HAT. Also supports the original Enviro HAT (fewer sensors) and runs on any hardware that supports these devices and the necessary libraries. (Testers welcome!)

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⚙️ Quick Install

Recommended: Install Script (PyPI-first)

Run this command on your Raspberry Pi:

bash <(wget -qO- https://raw.githubusercontent.com/JeffLuckett/ha-enviro-plus/main/scripts/install.sh)

Installation Methods:

• Latest stable (PyPI): ./install.sh (default)
• Specific version (PyPI): ./install.sh --release v0.1.1
• Development branch: ./install.sh --branch feature-branch
• Test mode: ./install.sh --test (validate without changes)
• Show installer info: ./install.sh --version

The installer automatically:

• Prioritizes PyPI for stable releases (faster, more reliable)
• Falls back to GitHub for development branches or specific versions
• Creates /opt/ha-enviro-plus and installs dependencies
• Prompts for MQTT host, username, and password
• Prompts for poll interval and temperature / humidity offsets
• Installs and starts the systemd service

Alternative: Direct PyPI Install

For advanced users who prefer manual installation:

pip install ha-enviro-plus

Then manually configure and start the service (see Manual Setup).

Home Assistant should auto-discover the sensors within a few seconds.

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🔧 Configuration

Configuration lives at:

/etc/default/ha-enviro-plus

Edit values safely, then restart the service:

sudo systemctl restart ha-enviro-plus

Example config:

MQTT_HOST=homeassistant.local
MQTT_PORT=1883
MQTT_USER=enviro
MQTT_PASS=<use_your_own>
MQTT_DISCOVERY_PREFIX=homeassistant
POLL_SEC=2
TEMP_OFFSET=0.0
HUM_OFFSET=0.0
CPU_TEMP_FACTOR=1.8

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🔧 Manual Setup

If you installed via pip install ha-enviro-plus, you'll need to manually configure the service:

1. Create Configuration File

sudo mkdir -p /etc/default
sudo tee /etc/default/ha-enviro-plus > /dev/null <<EOF
MQTT_HOST=homeassistant.local
MQTT_PORT=1883
MQTT_USER=enviro
MQTT_PASS=<use_your_own>
MQTT_DISCOVERY_PREFIX=homeassistant
POLL_SEC=2
TEMP_OFFSET=0.0
HUM_OFFSET=0.0
CPU_TEMP_FACTOR=1.8
EOF

2. Create Settings Directory

sudo mkdir -p /var/lib/ha-enviro-plus
sudo chown pi:pi /var/lib/ha-enviro-plus

3. Install Systemd Service

sudo tee /etc/systemd/system/ha-enviro-plus.service > /dev/null <<EOF
[Unit]
Description=Enviro+ → Home Assistant MQTT Agent
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
EnvironmentFile=/etc/default/ha-enviro-plus
WorkingDirectory=/opt/ha-enviro-plus
ExecStart=python3 -m ha_enviro_plus.agent
Restart=on-failure
RestartSec=5
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target
EOF

4. Start Service

sudo systemctl daemon-reload
sudo systemctl enable ha-enviro-plus.service
sudo systemctl start ha-enviro-plus.service

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🧰 Uninstall

Remove the agent and optionally keep the config:

bash <(wget -qO- https://raw.githubusercontent.com/JeffLuckett/ha-enviro-plus/main/scripts/uninstall.sh)

The uninstaller:

• Stops and disables the systemd service
• Removes /opt/ha-enviro-plus, log files, and settings directory
• Prompts to preserve /etc/default/ha-enviro-plus (interactive mode)
• Works in both interactive and non-interactive modes

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🧪 Testing

This project includes comprehensive tests to ensure reliability and maintainability.

Test Structure

• Unit Tests: Test individual components with mocked hardware
• Integration Tests: Test MQTT functionality and end-to-end workflows
• Hardware Tests: Test with real Enviro+ sensors (optional, requires hardware)

Running Tests

# Install development dependencies
pip install -r requirements-dev.txt

# Run all tests (excluding hardware)
pytest tests/ -m "not hardware"

# Run only unit tests
pytest tests/unit/

# Run only integration tests
pytest tests/integration/

# Run hardware tests (requires Enviro+ hardware)
pytest tests/hardware/

# Run with coverage
pytest tests/ --cov=ha_enviro_plus --cov-report=html

Test Coverage

The project aims for >=75% test coverage. Coverage reports are generated in HTML format and available in the htmlcov/ directory after running tests with coverage.

Continuous Integration

Tests run automatically on every push and pull request via GitHub Actions, testing against Python 3.9, 3.10, 3.11, and 3.12.

Development Setup

# Clone the repository
git clone https://github.com/JeffLuckett/ha-enviro-plus.git
cd ha-enviro-plus

# Option 1: Install in development mode (recommended)
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate
pip install -e .

# Option 2: Install from PyPI for testing
pip install ha-enviro-plus

# Option 3: Use the install script for development
./scripts/install.sh --branch main

# Install development dependencies
pip install -r requirements-dev.txt

# Run tests
pytest tests/ -m "not hardware"

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• Temperature Compensation: The temperature sensor runs warm due to CPU proximity. The agent now includes automatic CPU temperature compensation using a configurable factor (default 1.8). You can adjust this factor via Home Assistant or the config file for optimal accuracy.
• Calibration: Use the TEMP_OFFSET for fine-tuning individual installations, and CPU_TEMP_FACTOR to adjust the CPU compensation algorithm.
• Humidity readings depend on temperature calibration — adjust both together.
• Sound and particulate sensors are planned for v0.2.0; the agent functions fully without them.

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🧪 Version

v0.1.1 — Stable Release

This version includes:

• Complete Enviro+ sensor support (BME280, LTR559, Gas sensors)
• MQTT integration with Home Assistant discovery
• System telemetry (CPU temperature, load, memory, disk)
• Home Assistant control entities (reboot, restart, shutdown)
• Configurable polling intervals and calibration offsets
• CPU temperature compensation for accurate readings
• Graceful shutdown handling and configuration validation
• PyPI installation support (pip install ha-enviro-plus)
• Enhanced install script with PyPI-first approach
• Test mode for safe installation validation
• Comprehensive test suite with >=75% coverage

Next milestone (v0.2.0):

• Noise sensor (microphone to dB conversion)
• PMS5003 particulate sensor support
• 0.96" LCD display system with plugin architecture

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📜 License

MIT © 2025 Jeff Luckett