ESPHome Juntek DPM8650 MQTT & HTTP Tool

Control your Juntek DPM8650 50A Buck Converter using its RS485 Modbus interface. This setup integrates seamlessly with Home Assistant, Node-RED, or a simple web control interface using ESPHome YAML configuration

New: Use your DPM8650 as a powerful MPPT Solar Charge controller

ESP32 MQTT dongle

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Hardware Setup

Hardware Diagram

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Wiring Diagram

Wiring for the ESP32 to RS485 connection:

• TX Pin (ESP) → TX Pin (TTL to RS485 Board)
• RX Pin (ESP) → RX Pin (TTL to RS485 Board)

Ensure the TX and RX pins are connected as described:

For detailed ESPHome configuration, refer to the DPM8650 Controller YAML.

DPM8650 Configuration

To set up your Juntek DPM8650, follow these steps:

1. Long-press the SET button on your DPM8650 to enter the configuration menu.

2. Adjust the following settings:

   • Communication Port (5-CS): Set this to 1 to enable RS485 Modbus communication.

     

   • Baud Rate (6-bd): Set this to 009.6 for a baud rate of 9600.

     

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Interface Options

Depending on your use case, you can enable different interfaces in the DPM8650 Controller YAML.

1. Home Assistant API:

   • Keep the api: block if you're using Home Assistant integration.

2. MQTT for Node-RED:

   • Retain the mqtt: block if you're using MQTT for integration with Node-RED or other MQTT clients.

3. Web Interface:

   • Use the web_server: block if you prefer controlling the DPM8650 via a simple web interface.

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Home Assistant Integration

Here's a screenshot of how the DPM8650 sensors and controls appear in Home Assistant:

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Web Control Interface

You can also control the DPM8650 via a built-in web tool which you can find on your network at http://dpm8650_controller.local/

MQTT Configuration

MQTT Sensors and Controls

• MQTT Text Sensor 'CCCV Output State Label'

  • State Topic: dpm8650_controller/sensor/cccv_output_state_label/state

• MQTT Sensor 'MAX Output Voltage'

  • State Topic: dpm8650_controller/sensor/max_output_voltage/state

• MQTT Sensor 'MAX Output Current'

  • State Topic: dpm8650_controller/sensor/max_output_current/state

• MQTT Sensor 'Output Voltage'

  • State Topic: dpm8650_controller/sensor/output_voltage/state

• MQTT Sensor 'Output Current'

  • State Topic: dpm8650_controller/sensor/output_current/state

• MQTT Sensor 'Temperature'

  • State Topic: dpm8650_controller/sensor/temperature/state

• MQTT Number 'Set MAX Voltage'

  • State Topic: dpm8650_controller/number/set_max_voltage/state

• MQTT Number 'Set MAX Current'

  • State Topic: dpm8650_controller/number/set_max_current/state

• MQTT Switch 'Output Control'

  • State Topic: dpm8650_controller/switch/output_control/state
  • Command Topic: dpm8650_controller/switch/output_control/command

  

  Message payload string on to dpm8650_controller/switch/output_control/command enables Converter output

  

  Message payload string off to dpm8650_controller/switch/output_control/command disables converter output

• MQTT Binary Sensor 'CCCV Output State'

  • State Topic: dpm8650_controller/binary_sensor/cccv_output_state/state

MQTT Subscribe Sensors

• MQTT Subscribe Text Sensor 'MQTT Voltage Command'

  • Topic: home/commands/voltage
    (The converter subscribes to this topic. Publish a number (e.g., 12.3) to set the voltage to 12.3V)

• MQTT Subscribe Text Sensor 'MQTT Current Command'

  • Topic: home/commands/current
    (The converter subscribes to this topic. Publish a number (e.g., 12.3) to set the current to 12.3A)

  

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Resources

Library

Manual

Modbus Protocol