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Brian Rodriguez edited this page Dec 9, 2025 · 2 revisions

Configuration Guide

Configuration is done via .env file in the project root.

Environment Variables

Modbus Settings

# Serial port for Modbus RTU communication
MODBUS_PORT=COM11           # Windows: COM1, COM2, etc.
                            # Linux: /dev/ttyUSB0, /dev/ttyS0, etc.
                            # macOS: /dev/cu.usbserial-*

# Modbus device address (1-247)
MODBUS_SLAVE_ID=1

# Serial communication parameters
MODBUS_BAUDRATE=9600        # Options: 9600, 19200, 38400, 57600, 115200
MODBUS_BYTESIZE=8           # Data bits: 5, 6, 7, 8
MODBUS_PARITY=N             # N=None, E=Even, O=Odd
MODBUS_STOPBITS=1           # Stop bits: 1, 1.5, 2
MODBUS_TIMEOUT=1            # Timeout in seconds

# Modbus register addresses
MODBUS_FUNCTION_CODE=4      # 3=Holding, 4=Input registers
MODBUS_REGISTER_TEMP=1      # Temperature register address
MODBUS_REGISTER_HUMIDITY=2  # Humidity register address

Database Settings

# SQLite database file path
DATABASE_FILE=src/modbus_sensor_data.db

# Data retention period (0 = keep forever)
DATA_RETENTION_DAYS=0            # 0 = infinite retention
                                 # >0 = delete tables older than N days

Note: Database uses table-per-day partitioning (measurements_YYYYMMDD)

Web Server Settings

# Web interface host and port
APP_HOST=127.0.0.1         # 0.0.0.0 = all interfaces, 127.0.0.1 = localhost only
APP_PORT=8050              # Default port

# Debug settings
APP_DEBUG=False            # Flask debug mode (not used with Waitress)
DEBUG_LOGGING=False        # Enable detailed console output

# Localization
TIMEZONE=Europe/Amsterdam  # Timezone for timestamp display
DEFAULT_LANGUAGE=EN        # Default UI language: NL, EN, DE, FR, or ES

Production Server: Application uses Waitress WSGI server (not Flask dev server)

  • 8 worker threads for concurrent requests
  • Cross-platform (Windows/Linux/macOS)
  • Production-ready with proper error handling

XY-MD02 Sensor Defaults

The XY-MD02 sensor typically uses:

  • Baudrate: 9600
  • Slave ID: 1
  • Function Code: 4 (Input Registers)
  • Temperature Register: 1
  • Humidity Register: 2
  • Data format: value * 10 (e.g., 235 = 23.5 degrees)

Configuration Validation

The application validates configuration on startup:

  • Slave ID must be 1-247
  • Parity must be N, E, or O
  • Timeout must be positive
  • Warns on unusual baudrate values

Invalid configuration will prevent startup with clear error message.

Multiple Sensors

To monitor multiple sensors:

  1. Run separate instances on different ports
  2. Use different .env files
  3. Configure different MODBUS_SLAVE_ID values

Example:

# Terminal 1 - Sensor 1
PORT=8050 MODBUS_SLAVE_ID=1 python app.py

# Terminal 2 - Sensor 2
PORT=8051 MODBUS_SLAVE_ID=2 python app.py

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