HYMER Connect — Real-time motorhome/caravan sensors via SignalR (HACS custom integration)

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HYMER Connect for Home Assistant

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Custom integration to connect your HYMER / Erwin Hymer Group motorhome or caravan to Home Assistant with 130+ real-time sensors via SignalR.

Open your Home Assistant instance and open a repository inside the Home Assistant Community Store.

GitHub: BetaHydri/hymer-connect-ha

Supported Brands

All Erwin Hymer Group brands with a Smart Interface Unit (SIU):

HYMER · Buerstner · Dethleffs · Eriba · LMC · Carado · Laika · Sunlight · FreeOnTour · Niesmann+Bischoff

What You Get

130+ sensor entities streamed in real-time from your vehicle’s CAN bus, LIN bus, GPS, and connected components:

Category Sensors
Vehicle Odometer, speed, RPM, AdBlue level, fuel range, engine hours, coolant temp, gear position
Battery Voltage, current, SOC (%), chassis battery, charge phase, charger status, external charger voltage
Water Grey water level (%), grey water sensor
Temperature Indoor, outdoor, ambient, AdBlue
GPS Coordinates, altitude, heading, satellites, signal quality
Doors Driver, passenger, sliding, rear (open/closed)
Status Lock, ignition, handbrake, engine running, mains power, headlamp, cruise control
Heating Truma heater: fan speed, setpoint, electric power, fuel type, operating mode
Fridge Mode, status
Alarm Armed status, battery level
Lights Headlamp, high beam, parking, fog front/rear, turn signal, dimmer levels
Device tracker GPS position on the HA map

Screenshots

HYMER Connect Integration
HYMER Connect Integration1594×1308 153 KB

HYMER Connect Sensors
HYMER Connect Sensors1264×1192 34.8 KB

How It Works

The integration connects to the HYMER Connect cloud (SCC API + EHG Remote Access) and opens a persistent SignalR WebSocket to stream real-time sensor data from the vehicle’s Smart Interface Unit. Data is decoded from a custom protobuf format (PIA protocol) used by the official Hymer Connect app.

Setup Requirements

  • HYMER Connect app account (same credentials you use in the app)
  • An EHG Remote Access Refresh Token — must be captured once from the app’s network traffic using mitmproxy. Detailed step-by-step instructions are in the README.

Without the refresh token, only basic REST data (model, VIN, year) is available. With it, you get the full 130+ real-time sensors.

Installation (HACS)

  1. Add https://github.com/BetaHydri/hymer-connect-ha as a custom repository in HACS
  2. Install “HYMER Connect”
  3. Restart Home Assistant
  4. Go to Settings → Devices & Services → Add Integration → “HYMER Connect”
  5. Enter your credentials and EHG refresh token

A ready-to-use Lovelace dashboard is included in the repository.

Feedback, bug reports, and contributions are welcome on GitHub! Currently at v1.7.2.