OpenShrooly now includes temperature control with Home Assistant integration! While the Shrooly hardware doesn’t have built-in heating or cooling, OpenShrooly can request heating through the “Heat Requested” binary sensor that Home Assistant can monitor.

Dashboard Card

Temperature Card - Heating

The temperature card shows:

  • Current temperature in large text
  • Target range (if temperature control enabled)
  • HEATING badge when heat is being requested

Temperature Settings

Click the Temperature card on the dashboard to open the temperature control modal.

Temperature Control Modal

Interactive Slider Controls

The temperature control features similar drag-and-drop controls as humidity:

  • Enable Temperature Control checkbox: Turn temperature control on or off
  • Green center handle: Drag to set your target temperature (15-35°C)
  • Left/Right arrows: Drag to adjust the hysteresis range

How Temperature Control Works

The hysteresis band works the same as humidity control:

  • Heat requested when temperature drops below the lower bound (Target - Hysteresis)
  • Heat stops when temperature rises above the upper bound (Target + Hysteresis)

Example: With Target: 29.0°C and Hysteresis: 1.50°C:

  • Heat is requested below 27.5°C (29.0 - 1.5)
  • Heat stops above 30.5°C (29.0 + 1.5)

This prevents the heating system from constantly cycling on and off.

Home Assistant Integration

⚠️ Important: OpenShrooly can only request heating - it cannot control heating equipment directly. External heating equipment must be controlled via Home Assistant. I’m using a Sonoff smart plug with a 17W seedling mat underneath my OpenShrooly - that might not be enough power for all situations

Heat Requested Binary Sensor

The firmware provides a “Heat Requested” binary sensor that signals when heating is needed:

  • Sensor name: binary_sensor.openshrooly_XXXXXX_heat_requested
  • State: ON when heating needed, OFF when heating should stop

Setting Up Heating Automation

You’ll need to create a Home Assistant automation that:

  1. Monitors the binary_sensor.openshrooly_XXXXXX_heat_requested sensor
  2. Turns ON your heating equipment when the sensor state is ON
  3. Turns OFF your heating equipment when the sensor state is OFF

Example Home Assistant Automation

Home Assistant Automation Example

This automation:

  • Triggers when the “Heat Requested” sensor changes state
  • If heat is requested (sensor is “Hot”), turns ON the heating pad relay
  • Else turns OFF the heating pad relay

Replace switch.shrooly_heating_pad with your actual heating device entity in Home Assistant.

See the Home Assistant integration guide for complete automation examples.

Temperature Warnings

Below the main temperature controls, you’ll find the Temperature Warnings section:

  • Warning Minimum: Alert threshold for dangerously low temperature (10-25°C)
  • Warning Maximum: Alert threshold for dangerously high temperature (20-35°C)

Note: These thresholds only trigger warnings - Home Assistant integration is required to receive and act on temperature alerts.