ESPHome modbus configuration to read a Hiking DDS238-2 ZN/S Energy meter

README.md

ESPHome modbus polling of a single phase energy meter

This is my working configuration to poll a http://www.chinaenergymeter.com/1-1-15-dds238-2-zn-s-single-phase-din-rail-type-watt-hour-meter.html (I have the 65A hard wired variant - I've seen postings that the CT clamp version may not be as responsive

I'm using a wemos D1 mini (ESP8266) with a RS485 toTTL module (that's OK at 3.3v). This seems fine using software serial on D1/D2 at a polling rate of every 5s

GOTCHAS

• If the wemos stays connected to home assistant but CAN'T talk to the meter, HA will re-use the last value rather than marking it offline/NaN/unavailable

dds238-modbus.yaml

# esphome config for D1 mini  + rs485 modbus
# Andrew Elwell, 2023 with thanks to all those who've posted the modbus registers online


esphome:
  name: modbus-meter1
  comment: Modbus testing

esp8266:
  board: d1_mini
  framework:
    version: recommended

logger:
  level: INFO


status_led:
  pin:
    number: D4
    inverted: true

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  
api:

uart:
  tx_pin: 5
  rx_pin: 4
  baud_rate: 9600

modbus:
  # send_wait_time: 500ms
  # flow_control_pin: 5
  id: modbus1

modbus_controller:
  - id: meter
    address: 0x1
    modbus_id: modbus1
    setup_priority: -10
    update_interval: 5s

sensor:
  - platform: modbus_controller
    modbus_controller_id: meter
    name: Total Energy
    device_class: energy
    state_class: total
    unit_of_measurement: kWh
    register_type: holding
    address: 0x0000
    value_type: U_DWORD
    accuracy_decimals: 2
    filters:
      - multiply: 0.01  # 1/100

  - platform: modbus_controller
    modbus_controller_id: meter
    name: Export Energy
    device_class: energy
    state_class: total_increasing
    unit_of_measurement: kWh
    register_type: holding
    address: 0x0008
    value_type: U_DWORD
    accuracy_decimals: 2
    filters:
      - multiply: 0.01  # 1/100

  - platform: modbus_controller
    modbus_controller_id: meter
    name: Import Energy
    device_class: energy
    state_class: total_increasing
    unit_of_measurement: kWh
    register_type: holding
    address: 0x00A
    value_type: U_DWORD
    accuracy_decimals: 2
    filters:
      - multiply: 0.01  # 1/100

  - platform: modbus_controller
    modbus_controller_id: meter
    name: "Voltage"
    register_type: holding
    address: 0x000C
    unit_of_measurement: "V"
    device_class: voltage
    value_type: U_WORD
    accuracy_decimals: 1
    filters:
      - multiply: 0.1  # 1/10

  - platform: modbus_controller
    modbus_controller_id: meter
    name: "Current"
    device_class: current
    register_type: holding
    address: 0x000D
    unit_of_measurement: "A"
    value_type: U_WORD
    accuracy_decimals: 2
    filters:
      - multiply: 0.01  # 1/100

  - platform: modbus_controller
    modbus_controller_id: meter
    name: "Active Power"
    device_class: power
    register_type: holding
    address: 0x000E
    unit_of_measurement: "W"
    value_type: S_WORD

  - platform: modbus_controller
    modbus_controller_id: meter
    name: "Reactive Power"
    device_class: reactive_power
    register_type: holding
    address: 0x000F
    unit_of_measurement: "VAr"
    value_type: U_WORD

  - platform: modbus_controller
    modbus_controller_id: meter
    name: "Power Factor"
    device_class: power_factor
    register_type: holding
    address: 0x0010
    value_type: U_WORD
    accuracy_decimals: 3
    filters:
      - multiply: 0.001  # 1/1000

  - platform: modbus_controller
    modbus_controller_id: meter
    name: "Frequency"
    device_class: frequency
    register_type: holding
    address: 0x0011
    unit_of_measurement: "Hz"
    value_type: U_WORD
    accuracy_decimals: 2
    filters:
      - multiply: 0.01  # 1/100