How to Integrate IAMMETER Energy Meters into Home Assistant via Modbus TCP for Real-Time Solar Monitoring

How to Integrate IAMMETER Energy Meter into Home Assistant via Modbus/TCP

This tutorial guides you through integrating IAMMETER’s smart energy meters into Home Assistant using the Modbus TCP protocol. With this setup, you can build a real-time solar PV monitoring system, enabling local control and automation based on energy consumption and solar production.

1. Why Use Modbus/TCP to Integrate Smart Energy Meters

All IAMMETER smart energy meters support Modbus TCP, a widely-used protocol for industrial and home automation.

Key Benefits of Modbus TCP Integration in Home Assistant:

• High Real-Time Performance: Sampling rate up to 1 second (via scan_interval: 1), ideal for real-time control.
• Local Communication: No dependency on the cloud, ensuring privacy and stability.
• Full Parameter Monitoring: Voltage, current, power, import/export energy, and more.

2. Hardware & Software Requirements

Hardware Checklist

• IAMMETER Energy Meter
• A local network (your energy meter and Home Assistant must be on the same LAN)
• Home Assistant-compatible smart devices (e.g., Sonoff relay, temperature sensor)

Software Requirements

• Home Assistant version ≥ 0.107.0
• File Editor or SSH access to modify configuration.yaml

3. Step-by-Step Configuration Guide

Step 1: Find the IP Address of IAMMETER Meter

Check the IP address of your meter from the IAMMETER app or router interface (e.g., 192.168.1.6).

Step 2: Edit the Home Assistant Configuration

Add the following to your configuration.yaml:

modbus:
  - name: "IAMMETER_Hub"
    type: tcp
    host: 192.168.1.6  # Replace with your meter's IP
    port: 502
    sensors:
      - name: "Modbus_Power"
        slave: 1
        address: 2
        input_type: holding
        unit_of_measurement: "W"
        device_class: power
        data_type: int32
        scan_interval: 1
      - name: "Modbus_Voltage"
        slave: 1
        address: 0
        input_type: holding
        unit_of_measurement: "V"
        device_class: voltage
        data_type: uint16
        scale: 0.01
        precision: 1

Explanation of Key Parameters:

• slave: Usually 1
• address: Modbus register address
• scale and precision: For converting raw data to readable values

Step 3: Reference Table – Register Map

👉 Full Register Map of IAMMETER Meters

Step 4: Restart Home Assistant

After saving the configuration, restart Home Assistant. The new entities (e.g., sensor.modbus_power) will appear under Developer Tools → States.

4. Use Cases & Automation Scenarios

Use Case 1: Relay Control Based on Power Reading

Control Relay Based on Power Consumption

automation:
  - alias: "High Power → Turn On Relay"
    trigger:
      platform: numeric_state
      entity_id: sensor.modbus_power
      above: 1000
    action:
      service: switch.turn_on
      target:
        entity_id: switch.sonoff_s26

  - alias: "Low Power → Turn Off Relay"
    trigger:
      platform: numeric_state
      entity_id: sensor.modbus_power
      below: 500
    action:
      service: switch.turn_off
      target:
        entity_id: switch.sonoff_s26

💡 Example: When a kettle is on (1596W), the relay is turned on; when off (64W), the relay is turned off.

Use Case 2: Solar PV Monitoring in Home Assistant

By monitoring import_energy and export_energy, you can visualize how your solar PV system interacts with the grid.

👉 Tutorial: Monitor Your Solar PV System

5. Troubleshooting & Optimization Tips

1. Slow Data Refresh
   • Ensure scan_interval: 1 is configured (default may be 15s)
   • Avoid reading too many registers simultaneously
2. No Entities Shown
   • Check IP and port (e.g., telnet 192.168.1.6 502)
   • Confirm register addresses match your meter type (single-phase or three-phase)
3. Compare Other Integration Methods All IAMMETER → Home Assistant Integration Methods

6. Conclusion

By integrating IAMMETER smart energy meters into Home Assistant via Modbus TCP, you can build a fast, privacy-focused, and locally controlled solar monitoring and automation system. It's especially effective for load shifting, EV charging, and water heating based on solar surplus.

🔧 Accurate register mapping and scan_interval optimization are key to achieving 1-second-level responsiveness.

For advanced users, pairing this integration with InfluxDB and Grafana enables long-term energy analytics and performance tracking.

Real-World Applications of IAMMETER + Home Assistant:

• 🚗 EV Charging Automation Based on Solar Surplus
• 🔥 Water Heater Automation with Solar PV

At IAMMETER, our mission goes beyond monitoring—we aim to help solar users reduce electricity bills by maximizing solar self-consumption. Smart monitoring is the first step, but cost-saving is the ultimate goal.