Home Pump Monitor

A Java application that reads data from a heat pump via Modbus TCP and sends metrics to InfluxDB.

Features

• Reads Modbus holding registers from a heat pump
• Caches readings for 60 seconds to reduce load
• Sends temperature and pump status data to InfluxDB every minute
• Configurable via JSON file

Configuration

Edit src/main/resources/registryMapping.json to configure:

• Modbus TCP connection (address, port)
• InfluxDB connection (address, username, password)
• List of registers to read with descriptions

Additional mapping fields (optional):

• useMock (Boolean, top-level): When true, the application runs with a local MockRepository instead of attempting to connect to a Modbus device. Useful for local development when a device is not available (default: false).

• unitId (Integer): Modbus slave/unit id for the register (default: 1)

• scale (Double): Multiply raw device value by this to obtain display value (default: 0.1)

• dataType (String): Data type used for the locator (e.g. TWO_BYTE_INT_SIGNED). Supported values: TWO_BYTE_INT_SIGNED, TWO_BYTE_INT_UNSIGNED, FOUR_BYTE_INT_SIGNED, FOUR_BYTE_INT_UNSIGNED, FOUR_BYTE_FLOAT (the latter reads two adjacent registers and interprets as IEEE754 float). For devices with non-standard word order, the following swapped variants are supported: FOUR_BYTE_INT_SWAPPED, FOUR_BYTE_INT_UNSIGNED_SWAPPED, FOUR_BYTE_FLOAT_SWAPPED (word order low/high).

• signedLegacyWrap (Boolean): When true, apply legacy negative wrap decoding for values near -32768 (default: true)

Build and Run

mvn clean package
java -jar target/home-pump-1.0.0.jar

Requirements

• Java 21
• Modbus TCP accessible heat pump
• InfluxDB instance