Shelly Plus Add-On Sensor Interface for Temperature & Humidity Monitoring
The Shelly Plus Add-On is a galvanically isolated sensor interface designed to expand the capabilities of Shelly Plus, Gen3, and Gen4 devices. Use it to measure temperature and humidity using its 1-Wire terminals, or connect various analog and digital sensors for complex home automation and higher efficiency. Compatible with most Arduino sensors, this versatile add-on is perfect for smart homes, greenhouses, aquariums, irrigation systems, and more.
Why You'll Love the Shelly Plus Add-On
-
Multi-Sensor Support: Connect up to 5 DS18B20 temperature sensors or 1 DHT22 temperature & humidity sensor
-
Analog & Digital Inputs: Versatile sensor connectivity for custom automation scenarios
-
Galvanic Isolation: Protects your Shelly devices and sensors from electrical interference and short circuits
-
Arduino Compatible: Works with a wide range of third-party sensors including soil moisture, motion, distance, and reed switches
-
Compact Design: Tiny 37 × 42 × 15 mm footprint fits easily in junction boxes
-
No Hub Required: Connects directly to your Shelly Plus or Gen3/Gen4 device
Perfect for Advanced Home Automation
The Shelly Plus Add-On unlocks new automation possibilities across residential, commercial, and agricultural applications. Monitor water temperature in your pool or aquarium, automate greenhouse climate control, track soil moisture for smart irrigation, or add door/window sensors using reed switches. The galvanically isolated interface ensures signal integrity and protects your equipment if sensors fail or short out.
Easy Integration with Your Shelly Ecosystem
The Add-On simply clips onto compatible Shelly Plus relay devices (such as Shelly Plus 1, Plus 1PM, Plus 2PM, Plus i4, and Plus i4DC) as well as Gen3 and Gen4 devices. It's powered directly from the host device at 3.3V DC, consuming less than 0.5W without sensors. Control and monitor your sensors remotely via the Shelly Smart Control app (iOS & Android), and integrate with Alexa, Google Home, Home Assistant, and SmartThings.
Real-World Applications
-
Smart Irrigation: Pair with a soil moisture sensor to water your garden only when needed, saving water and optimising plant health
-
Aquarium & Pool Monitoring: Track water temperature precisely and automate heaters or circulation pumps
-
Greenhouse Automation: Monitor temperature and humidity to create the perfect growing environment
-
Garage Door Status: Connect a reed switch to track whether your garage door is open or closed remotely
-
HVAC Optimisation: Multi-zone temperature monitoring for intelligent climate control
What's in the Box
- Shelly Plus Add-On module
- Multilingual user and safety guide
Note: Temperature and humidity sensors (DS18B20, DHT22) are sold separately.
Full Specifications
General
| Model |
Shelly Plus Add-On |
| Product Type |
Galvanically Isolated Sensor Interface |
| Compatibility |
Shelly Plus, Gen3, and Gen4 devices |
| Sensor Support |
Up to 5 × DS18B20 or 1 × DHT22 |
Electrical
| Power Supply |
3.3 V DC (from host Shelly device) |
| Power Consumption |
Less than 0.5 W (without sensors) |
| Analog Input Range |
0 - 10 V DC |
| Analog Input Resolution |
0.1 V DC |
| Analog Input Sampling |
1 Hz |
| Analog Measurement Accuracy |
Better than 5% |
| Wire Terminals |
Max 1 mm² |
| Screw Terminal Torque |
0.1 Nm / 0.89 lb-in |
| Cable Length (without insulation) |
4.5 mm |
Physical
| Dimensions (H × W × D) |
37 × 42 × 15 mm ±0.5 mm / 1.46 × 1.65 × 0.59 in |
| Weight |
105 g / 3.70 oz |
| Material |
Plastic |
| Colour |
Black |
Environmental
| Operating Temperature |
-20°C to 40°C |
| Operating Humidity |
30% to 70% RH |
| Maximum Altitude |
2000 m |
Connectivity
| Interface |
Shelly proprietary serial interface |
| Connection to Host |
Direct clip-on connection to Shelly Plus/Gen3/Gen4 device |
| Inputs |
1 × Analog input, 1 × Digital input |
| Outputs |
VREF, VREF + R1 (pull-up resistor), 2 × Ground |
Smart Features
| Control & Monitoring |
Shelly Smart Control app (iOS & Android) |
| Voice Assistants |
Amazon Alexa, Google Home |
| Integrations |
Home Assistant, SmartThings, openHAB |
| MQTT Support |
Yes |
| Hub Required |
No |
Warranty & Compliance
| Warranty |
3 years (manufacturer standard warranty) |
| Manufacturer |
Allterco Robotics EOOD, Bulgaria |
| Compliance |
CE, RoHS, EMC Directive 2014/30/EU, Low Voltage Directive 2014/35/EU |
Specifications are sourced from the manufacturer product page and may be updated. Sensors (DS18B20, DHT22) sold separately. Professional installation by a qualified electrician is recommended for electrical safety.
