Shelly PLUS ADD-ON

Product Introduction

The Shelly Plus Add-On is an expansion module designed to extend the functionality of Shelly Plus, Gen3, and certain Gen4 smart relays. It provides a sensor interface that allows external sensors to be connected directly to a Shelly device, enabling advanced monitoring and automation scenarios within a smart home system.

The module connects directly to compatible Shelly devices through a dedicated interface and does not operate as a standalone device. Once installed, it allows the host Shelly relay to collect data from multiple environmental or analog sensors, making it possible to create automation routines based on temperature, humidity, light levels, water levels, and other conditions.

With support for both digital and analog sensor inputs, the Shelly Plus Add-On provides flexibility for advanced automation projects, energy management, and environmental monitoring in residential or commercial smart home systems.

Key Features

Sensor Interface Expansion
Adds support for external sensors to compatible Shelly Plus and Gen3 devices for advanced monitoring and automation.

Temperature and Humidity Monitoring
Supports up to five DS18B20 temperature sensors or one DHT22 temperature and humidity sensor for environmental monitoring.

Analog and Digital Inputs
Includes one analog input and one digital input for connecting a wide range of sensors and monitoring devices.

Wide Sensor Compatibility
Compatible with many third-party sensors, including light sensors, motion detectors, water level sensors, soil moisture sensors, and other Arduino-compatible modules.

Galvanically Isolated Design
Provides electrical isolation between the Shelly relay and connected sensors for improved safety and reliability.

Seamless Integration with Shelly Devices
Snaps directly onto supported Shelly Plus modules for easy installation and automatic communication with the host device.

Smart Home Integration

The Shelly Plus Add-On works in combination with compatible Shelly devices such as:

• Shelly Plus 1
• Shelly Plus 1PM
• Shelly Plus 2PM
• Shelly Plus i4 / i4DC
• Shelly Gen3 devices

Once installed, the connected sensors can trigger automation rules within the Shelly Smart Control platform or integrated systems such as:

• Amazon Alexa
• Google Home
• Home Assistant
• MQTT automation platforms

Example automation scenarios include:

• Turning on ventilation when humidity rises
• Activating irrigation when soil moisture is low
• Monitoring water levels in tanks or pools
• Adjusting lighting based on ambient light levels

Technical Specifications

Product Type: Sensor Interface Expansion Module
Model: Shelly Plus Add-On
Compatibility: Shelly Plus and selected Gen3 devices
Sensor Inputs:
• 1 × Analog input
• 1 × Digital input

Supported Sensors:
• DS18B20 temperature sensors (up to 5)
• DHT22 temperature and humidity sensor
• Photoresistors (LDR)
• PIR motion sensors
• Soil moisture sensors
• Liquid level sensors
• Other analog sensors (0–10 V)

Interface Type: Direct plug-in connector
Isolation: Galvanically isolated sensor interface
Installation: Connects directly to compatible Shelly Plus device

What’s in the Box

Shelly Plus Add-On module
User manual