Solis ESPHome

Hardware

They are designed for my hardware solution which can be found at

https://store.eplop.co.uk/products/rs485-to-wifi-adaptor-for-home-assistant

This includes a custom PCB which then uses a Wemos D1 mini board and then you can connect to any RS485 device which uses modbus.

Software

The following is breakdown of the sections required.

Configuration file

modbus:
  flow_control_pin: D1
  id: modbus1
  send_wait_time: 200ms  
uart:
  id: mod_bus
  tx_pin: TX
  rx_pin: RX
  baud_rate: 9600
  stop_bits: 1

These two sections tell ESPHOME that we are going to be using modbus for communicating with the Inverter and the pins we shall be using for sending / receiving and also the flow control pin which controls when the device will be sending or receiving data.

modbus_controller:
  - id: solis
    ## the Modbus device addr
    address: 0xA
    modbus_id: modbus1
    setup_priority: -10
    command_throttle: 300ms
    update_interval: 30s

the next important configuration is to define a modbus controller which uses the id which created earlier. One important setting here is the

address: 0xA

this tells esphome what id the device is configured for. The value here is 0xA which is 10. If you have modified your inverter to use something different then you shall need to update the value accordingly.

For reading information you must configure every value you which to read/write. Here we refer to the modbus controller which we have setup in the modbus_controller_id.

sensor:
  - platform: modbus_controller
    modbus_controller_id: solis
    id: inverter_tempterature
    name: "Inverter Temperature"
    address: 33093
    unit_of_measurement: "°C" 
    register_type: read
    value_type: U_WORD
    accuracy_decimals: 1
    filters:
      - multiply: 0.1

To breakdown each item

    id: inverter_tempterature

This is an ID which you assign to the device which will be used within Home Assistant.

    name: "Inverter Temperature"

This is a friendly name which we shall be assigned and used within Home Assistant.

    address: 33093

This part is very important as it is the address which ESPHOME will use for reading. This is unique for every item you wish to read and you should be able to find a list of what registers are available for your inverter from Solis.

    unit_of_measurement: "°C"

As per the name this defines the unit of measurement be it degree in this example of V for voltage.

    register_type: read

This defines if the registers is a read or write type. Typically most registers are read only.

    value_type: U_WORD

This defines the length of the data being read, typically this is a UWORD for a single item.

    accuracy_decimals: 1

This tells ESPHOME how you wish to present the data, you can have 1 decimal place as in this example or 2 or even 0 for no decimal places and just whole numbers.

    filters:
      - multiply: 0.1

Lastly this defines the multiplying factor. Registers show a larger number than is shown so a multiplying factor must be set so that it returns a valid figure.