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Raspberry Pi Environmental Monitoring System

Real-time indoor air quality and environmental monitoring using multiple sensors connected to a Raspberry Pi, with OLED display output and InfluxDB data logging.

Hardware

  • ENS160 — Air Quality Sensor (VOC, eCO2, AQI)
  • BME280 — Environmental Sensor (Temperature, Pressure, Humidity)
  • TMP117 — High-Precision Temperature Sensor
  • SSD1306 — 128×64 OLED Display

Features

  • Real-time monitoring of temperature, humidity, pressure, AQI, TVOC, and eCO2
  • Multi-page OLED display with temperature graphing and environmental recommendations
  • Automatic data validation and sensor health tracking
  • Batch data transmission to InfluxDB with RAM-based caching
  • Graceful error handling with automatic recovery
  • UBA (German Federal Environmental Agency) guideline compliance

Project Structure

pi-sensor/
├── ens160AirQualitySensor.py    # Main monitoring application
├── requirements.txt
├── docs/
│   ├── air-quality-guide.md     # Interpreting sensor readings
│   ├── ENS160.md                # ENS160 sensor reference
│   └── SSD1306.md               # SSD1306 display API reference
├── examples/
│   ├── display/                 # SSD1306 OLED display examples
│   ├── sensors/                 # DHT22 sensor scripts
│   └── buzzer/                  # PiicoDev buzzer example
└── assets/                      # Bitmap images for display

System Architecture

graph TD
    subgraph Sensors
        TMP[TMP117 Temperature] --> TC[Temperature Compensation]
        BME[BME280 Environmental] --> HC[Humidity Compensation]
        TC & HC --> ENS[ENS160 Air Quality]
    end

    subgraph Processing
        ENS --> VLD[Data Validation]
        VLD --> Cache[RAM Cache]
        Cache --> |Batch| IDB[InfluxDB]
        VLD --> |Real-time| DISP[OLED Display]
    end

    subgraph Analysis
        VLD --> ENV[Environmental Score]
        ENV --> REC[Recommendations]
        REC --> DISP
    end

    subgraph Monitoring
        VLD --> Health[Health Monitor]
        Health --> Error[Error Counter]
        Error --> Status[Status Display]
        Status --> DISP
    end
Loading

Display Pages

The OLED cycles through five pages:

  1. Main Stats — Temperature, humidity, pressure, AQI rating
  2. Air Quality — AQI score, TVOC (ppb), eCO2 (ppm)
  3. Temp Graph — Rolling temperature history with min/max
  4. Sensor Health — Error counts per sensor (shown only when issues exist)
  5. Environment — Comfort score and actionable recommendations

Installation

Prerequisites

sudo apt-get update
sudo apt-get install -y python3-pip python3-smbus i2c-tools

# Enable I2C
sudo raspi-config  # Interface Options → I2C → Enable

# Verify sensors are detected
sudo i2cdetect -y 1

Setup

pip3 install -r requirements.txt
export INFLUXDB_TOKEN="your-token-here"

Configuration

Edit the CONFIG dictionary in ens160AirQualitySensor.py:

CONFIG = {
    'MEASUREMENT_INTERVAL_MS': 1000,
    'INFLUXDB': {
        'URL': "http://your-influx-server:8086",
        'ORG': "your-org",
        'BUCKET': "sensorData",
    },
    'SENSOR_LOCATION': "room-name",
}

Run

python3 ens160AirQualitySensor.py

Run as a Service (optional)

sudo nano /etc/systemd/system/air-quality.service
[Unit]
Description=Air Quality Monitoring
After=network.target

[Service]
Environment=INFLUXDB_TOKEN=your-token-here
ExecStart=/usr/bin/python3 /path/to/ens160AirQualitySensor.py
WorkingDirectory=/path/to/script/directory
Restart=always
User=pi

[Install]
WantedBy=multi-user.target
sudo systemctl enable air-quality
sudo systemctl start air-quality

InfluxDB Data Schema

Measurement: sensorReading
Tags:    sensor, location
Fields:  temperature, humidity, pressure, aqi, tvoc, eco2, aqi_rating, eco2_rating, sensor_status

Troubleshooting

Problem Check
Sensor not found I2C connections, sudo i2cdetect -y 1, power
InfluxDB errors Network, token permissions, bucket exists
Display issues I2C address conflicts, power supply
ENS160 not ready Allow warm-up period (up to a few minutes)

Logs are written to stdout. Monitor with:

journalctl -u air-quality -f          # if running as service
python3 ens160AirQualitySensor.py 2>&1 | tee sensor.log  # if running directly

Documentation