Master Unit.

The Master Unit is the central controller that manages all modules in your camper. Built around the powerful ESP32-C6, this board acts as the bridge between your wired system bus and your smart home interface (Home Assistant). Thanks to its focus on a wired connection, you eliminate unnecessary Wi-Fi radiation and minimize the power consumption of your off-grid setup.

  • OLED Display & Status LED: Provides instant insights into your IP address, system status, and the real-time power consumption of all connected modules.
  • Push Button: A physical button to instantly turn off the display and LED. Ideal for preventing light pollution in the sleeping area during the night.
  • USB-C Programming: For effortless firmware updates and serial debugging via the built-in USB port.
  • Audible Status & Alarm (Buzzer): The built-in buzzer provides immediate audible feedback for system errors or critical thresholds, such as low battery voltage or overheating. This ensures you are instantly alerted to issues in the camper, even if the display is turned off for the night.
  • Ethernet Port: For a robust, wired connection to your router. Far more stable and energy-efficient than Wi-Fi.
  • The System Bus: The central port that communicates with all your other modules over a rugged cable connection using a I2C signal
  • RS485: Enables direct communication with industrial equipment such as inverters, solar chargers, and battery monitors using the Modbus protocol. Thanks to the built-in direction control, this is the ideal port for reading external energy systems. Additionally, this port supports our own Modbus expansion modules. Unlike the modules on the System Bus (I2C), these Modbus modules can communicate over long distances—ideal for placing sensors or displays anywhere in the camper without any signal loss.
  • External Antenna Connector (U.FL): The Master Unit is equipped with an ESP32-C6-WROOM-1U module featuring an external U.FL antenna connector. This guarantees optimal wireless range, even when the module is tucked away deep behind the metal walls of a camper.
  • ESP32-C6: The beating heart of the Master Unit. This powerful microcontroller is not only energy-efficient but also future-proof at a hardware level, featuring native support for Matter, Thread, and Zigbee.
  • TVS Diode: For ultimate safety, the main 12V input is equipped with a TVS diode. This component clamps dangerous voltage spikes instantly, keeping the sensitive onboard electronics fully protected against fluctuations in the camper’s electrical system.
  • Stable 12V Power Supply & Reverse Polarity Protection: The board features an SS34 Schottky diode for reverse polarity protection, ensuring that an accidental inverted connection won’t destroy your system. Additionally, the 12V line to the system bus is guarded by a 1.1A Polyfuse, which automatically resets itself after a short circuit in the wiring is cleared.

Technical specifications.

Powersupply8-15V DC
Powerconsumption0 – max.30W
ProcessorESP32-C6 (ondersteunt Matter, Thread, Zigbee en Wifi 6)
NetworkW5500 Ethernet via SPI
Bus-Voltage12V DC
CommunicationI2C
Extra PortsRS485
Dimensions (LxWxH)72x95X60mm
VariantsAvailiable as kit or digital file.

Switches
  • switch.display_power
  • light.led_brightness
  • button.master_unit_reboot
  • switch.master_unit_buzzer
Sensors
  • sensor.master_unit_ip_address
  • sensor.master_unit_wifi_signal
  • sensor.systembus_voltage
  • sensor.systembus_current
  • sensor.systembus_power
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