Nautilis iRelay PRO

Professional fermentation relay for advanced monitoring setups.

Nautilis iRelay PRO is intended for advanced fermentation monitoring where data reliability, local access and integration with other systems are important. It can receive hydrometer data and forward it to supported platforms for logging, visualization or automation.

Main features

Advanced fermentation data relay
Designed for demanding monitoring setups
MQTT and automation friendly workflow
Local web configuration
Remote data forwarding support

Gallery

Nautilis iRelay PRO — Smart WiFi Controller

Description:
The Nautilis iRelay PRO is an advanced modular WiFi environmental controller that builds upon the proven Nautilis V8 temperature controller. Designed for precision and flexibility, it combines temperature control with real-time monitoring of pressure, humidity, and CO₂ — all integrated into one compact device. Perfect for fermentation chambers, kegerators, grow environments, and other applications requiring reliable climate and pressure management.

A smart temperature and environmental controller designed for seamless integration with Home Assistant.
It combines precise temperature control with environmental sensing and advanced connectivity.

Key Features

Graphical CO₂ visualization with color-coded zones:
🟢 0–1000 ppm (Good), 🟡 1000–1400 ppm (Moderate), 🟠 1400–1800 ppm (Poor), 🔴 Above 1800 ppm (Bad).
Relative humidity display with intuitive color levels:
🔵 0–40% (Dry), 🟢 40–60% (Comfort), 🟠 60–90% (Humid), 🔴 Above 90% (High humidity).
Air pressure monitoring in bar or psi with full calibration support.
Two primary temperature sensors — one internal and one external (2m cable) for remote monitoring and control.
- Temperature units selectable in °C or °F.
- Calibration support for main sensor.
Supports up to three additional temperature sensors.
Dynamic visual indicators:
- 🔺 Red arrow when temperature is rising.
- 🔻 Blue arrow when temperature is falling.
- Target temperature background shows system state:
  🔴 Heating | 🔵 Cooling | ⚪ Idle | ⚫ Error.
Configurable delay timer and hysteresis display for precise temperature management.
Full iSpindel hydrometer integration — receives and displays all key data (specific gravity, temperature, battery, angle, etc.) and forwards it to Home Assistant.
Independent heating and cooling relay control — both can operate simultaneously or independently.
You can disable one or both, turning the device into a monitoring-only unit.
Automatic Home Assistant Discovery for all sensors and relays (no manual setup).
Compact TFT display (240×320) with responsive interface and clear visual status indicators.

Technical Specifications:

Parameter	Specification
Power Supply	5 V USB-C regulator
Communication	Wi-Fi (MQTT protocol)
ADC Module	ADS1115, 16-bit precision (0–5 V input)
Sensors	3 × DS18B20, 1 × SCD4x, 1 × Pressure sensor
External Data	iSpindel WiFi Hydrometer
Output	2 × Relay (Heating/Cooling)
Pressure Units	bar / psi (selectable)
Integration	Home Assistant auto-discovery
Firmware	OTA upgradable
Display	2″ TFT 240×320 full-color screen

The controller is designed for DIY installation in systems of your own choice. The controller comes without a relay module, and the number of thermometers must also be specified. The controller is powered by a 5V USB C power supply. The power supply is not included. If you want a Relay module and power supply, please contact us by email so we can make you an offer for the components.

Setup on Home Assistant

Controller Configuration for Home Assistant via MQTT

The controller is designed for seamless integration with Home Assistant, primarily through MQTT communication. To ensure proper operation, make sure you have an MQTT broker (such as Mosquitto) configured on your Home Assistant setup.

Automatic Device Discovery

Thanks to MQTT Discovery, the controller and its sensors will be automatically recognized in Home Assistant once the controller is connected to your MQTT broker. There is no need for manual configuration in configuration.yaml or additional automations.

Device Features:

The controller will appear in Home Assistant as a thermostat device.
It supports setting a target temperature and reports the current temperature in real-time.
You can adjust the temperature directly from the Home Assistant user interface.

Setup Instructions:

Ensure MQTT is Enabled: Make sure the MQTT broker is properly set up and working in your Home Assistant. The controller will automatically send discovery messages to Home Assistant.
Controller Discovery: Upon connection, the controller will appear in the "Devices" section of Home Assistant as two separate devices:
- Controller: Manages the thermostat, target temperature, and heating/cooling modes.
- Sensors: Displays the temperature readings from the connected sensors.
Adjusting Temperature: Use the thermostat control in the Home Assistant UI to set the desired temperature. The setpoint will automatically be sent to the controller via MQTT.

Example:

Once configured, you can easily control the temperature through the Home Assistant dashboard. The system supports fine temperature adjustments, for example, with a step size of 0.1°C, allowing precise control over your heating or cooling system. There’s no need to add manual entries or automations in configuration.yaml. The controller will handle everything via MQTT discovery.