How to Smart-Control a Garage Door with Shelly Plus 1 and Real State Feedback

The Danger of Blind Control: A Real-Life Experience

A few months ago, I almost locked my cat inside the garage. As I was driving away, I pressed my old Somfy RTS remote control without looking back. That was the exact moment I realized I needed to automate my garage door opener, but above all, get a 100% reliable open/closed status in Home Assistant. I couldn’t rely on simple time-based estimates anymore.

The ultimate solution? The Shelly Plus 1 micro-relay. Thanks to its dry contact interface, it is the safest option to trigger an electronic garage motor board without risking sending 230V into it.

Why the Shelly Plus 1 is Perfect for this Project

• Dry Contact: The I (Input) and O (Output) terminals are completely isolated from the module’s power supply (L/N).
• Configurable SW Input: You can connect a magnetic limit switch sensor to detect the exact physical position of the door.
• Local Reliability: No cloud needed; it communicates locally via MQTT or the native Shelly Home Assistant integration.

Step 1: Secure Wiring Diagram

Before any wiring, turn off your main circuit breaker. For my setup, I powered the Shelly Plus 1 with 230V AC (L and N terminals). If you prefer low voltage, the Shelly can also be powered by 12V or 24-48V DC by adjusting the hardware jumper.

Connect the I and O terminals of the Shelly in parallel with the « wall button » trigger terminals (usually marked as Start or Cyc) on your garage door motor. For the magnetic sensor, mount the wired part on the door frame and the magnet on the moving door panel (positioned so they meet when the door is fully closed). Connect the sensor’s two wires between the SW terminal and the L terminal (if using 230V AC, or GND if using DC).

Step 2: Configuring the Shelly Plus 1

Once powered back on, connect to the Shelly’s temporary AP to open its web interface. Apply the following settings:

• Auto-Off Timer: Set an automatic off timer of 1 second. This simulates a momentary push button switch.
• Input Mode: Set the SW input to « Detached » mode. This ensures that the sensor state changes do not trigger the relay mechanically.

Step 3: Integration with Home Assistant

Using the native Shelly integration, the module is auto-discovered. To get a clean cover component, I configured a template cover in my configuration.yaml that links the relay trigger to the state of the SW input. Now, I control my garage door safely, with visual assurance of its true state.