RS485 communication protocol


  • Hi, I bought a 60A MPPT controller (SKU:US-L03APDMPPT60A-1) and I'd like to be able to integrate it into my HomeAssistant instance so that i can see my stats there. 

    I would like to be able to read the data from the rs485 port. Can you guys give me some information on the protocol? Is it modbus, etc. and if so which registers have which information?

    I would like it even better if you could disclose the bluetooth protocol for the BT-02 module so I could do it wirelessly.

    Thanks for any insights you may be able to provide!



  • We got a bluetooth module specially designed for our MPPT controller. It can read the data from rs485 port as you wish. Find it on eco-worthy online store:)

     


  • @Bryce Freeman I own the BT-02. I would like to be able to get the data off of it outside of the solar mate app. 


  • @Casey Hanner Hi, I was told the answer is no...the app is the only way to get the data. Sorry!


  • @Casey Hanner If you're fine with writing your own code, look on github for libmodbus.  If you're running Linux, you should be able to install it from packages.  The function modbus_read_registers() on address 0 (read 16 bytes from it) will give you all the info you're looking for.  Less than 100 lines of code including blank lines and some database calls.


  • If you want to use the RS485 port as a wired connection..

    https://github.com/skagmo/esmart_mppt/issues/5

    There's a huge number of individuals who have written their own code.

    Using the wiring connection from the link above and the software from here..

    https://github.com/CaptainTactful/esmart3_mppt_CTfork1

    pc-software.rar is what you're after.

    You need to be a bit techy and use a bit of savvy but nothing special.


  • Hello Casey Hanner, you can refer to these steps:

    1. Identify Communication Protocol: Check the controller's manual or datasheet to confirm if it uses Modbus RTU over RS485.

    2. Modbus RTU Setup: If the controller uses Modbus RTU, you will need the following information:

      • Baud Rate: Typically 9600, 19200, etc.
      • Data Bits: Usually 8
      • Parity: None, Even, or Odd
      • Stop Bits: 1 or 2
      • Slave Address: Unique address assigned to the device on the Modbus network.
    3. Register Mapping: The controller will have a specific set of Modbus registers that hold various pieces of data such as voltage, current, power, coreball, etc. The mapping of these registers is usually provided in the controller’s documentation.

    4. Connecting to HomeAssistant: You can use the HomeAssistant Modbus integration to connect to your controller. You will need a USB-to-RS485 adapter to connect your controller to your HomeAssistant server.


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