Verified compatibility
We test every device for these ecosystems. For non-standard integrations contact us before ordering.
- Home Assistant
- Zigbee
- Matter
- KNX
- Wi-Fi
Compatibility
Works with these ecosystems
Ecosystems
- Home Assistant
- Google Home
- Amazon Alexa
What it is, who it's for, what it does
About this product
The Shelly Plus Add-on starts from one idea: extending the measurement capability of a Shelly relay that is already mounted in the distribution board. The module has no radio of its own - it connects over a proprietary serial interface to a Shelly Plus, Gen3 or Gen4 host and is powered with 3.3 V directly from it.<br><br>Its terminals accept up to five DS18B20 temperature sensors on the 1-Wire bus, one combined DHT22 sensor (temperature and humidity), NTC resistors, photoresistors, PIR or soil-moisture sensors, and analog sensors with a 0-10 V output. A dry digital input and a built-in 0-10 V voltmeter round out the interface.<br><br>Galvanic isolation protects the host device, while the readings are forwarded through the host Wi-Fi to the app and scenes. It is a compact way to turn an ordinary relay into a monitoring node.
- DeliveryFree from 1500 MDL
- Returns30 days to return
- Warranty24 months
15+projects delivered300+devices installed3 yearslocal-first experienceChișinăushowroom Columna 153Book a showroom visit →
CasaSmart essentials
What it works with, what it needs, what you can do
Install & requirements
What you need on your side and what we deliver.
- Zigbee hub or Matter gateway for wireless variants
- 65 mm back-box or DIN panel for wired variants
- Local setup on Home Assistant — included in install
Smart scenarios
Three typical automations we set up after the install.
- 01Morning: warm light + blinds up + climate at 22 °C
- 02Leaving: lights off, arm sensors, close the gas
- 03Evening: warm ambient + cinema scene
Where it works
Use cases
In a Chisinau flat the host relay reports flow and return temperatures to the app and warns on overheating.
Up to 5 DS18B20 sensors wired to a Shelly Plus 1PM track flow, return and water heater.
When basement humidity exceeds the threshold, a scene starts a dehumidifier through another Shelly relay.
A DHT22 sensor reports temperature and humidity to the Shelly host.
A 0-10 V liquid-level sensor is read by the Add-on and monitored remotely in the app.
The analog input takes the signal of a process sensor with a 0-10 V output.
Analytics
See consumption — save on bills
Real-time consumption tracking via the eWeLink app. Daily, weekly and monthly history helps identify the most energy-hungry devices.
For the installerTechnical specificationsfull spec · wiring · datasheet
For the installer
Technical specifications
full spec · wiring · datasheet
Power
- Power supply
- 3.3 V
- Power consumption (no sensors)
- < 0.5 W
- VCC max current
- 10 mA
Connectivity
- DS18B20 temperature sensors
- up to 5 pcs
- DHT22 sensors
- 1 pcs
- Digital input
- 1 (dry)
- Analog / voltmeter input
- 0 to 10 V
- Host connection
- proprietary serial interface
Physical
- Dimensions
- 37 x 42 x 15 mm
- Weight
- 105 g
Environment
- Operating temperature
- -20 to 40 °C
- Humidity range
- 30 to 70 % RH
Other
- Certifications
- CE, UKCA, RoHS
Support
Frequently asked questions
Does the Shelly Plus Add-on work without another Shelly device?
No. The Add-on is a sensor interface that is powered with 3.3 V and talks over a proprietary serial link to a Shelly Plus, Gen3 or Gen4 host. Without a host it has no power and transmits no data.How many temperature sensors can I connect to the module?
Up to five DS18B20 sensors on the 1-Wire bus, or alternatively one DHT22 sensor for temperature and humidity. For five sensors keep the bus cable as short as possible.Does the Shelly Plus Add-on have its own Wi-Fi or Bluetooth?
No. The module has no radio of its own. Wireless connectivity and integrations with the app, Home Assistant, Google Home or Alexa are provided by the Shelly host device it is connected to.What types of analog sensors does the input accept?
The analog input and built-in voltmeter work in the 0-10 V range with a 0.1 V threshold. This lets you read 0-10 V output sensors, 10 kΩ NTC resistors, photoresistors or liquid-level sensors.Can I mount the module in the distribution board?
Yes. The 37 x 42 x 15 mm, 105 g enclosure mounts next to the host relay in the board or behind a switch. The maximum conductor cross-section is 1 mm² and the operating range is -20 °C to 40 °C.Do you offer installation for this module in Chisinau?
This product is currently out of stock and installation is not enabled on the card. The CasaSmart team can advise free of charge and schedule a paid installation together with a compatible host device.
Manager guidance
Questions about this product?
A CasaSmart manager calls you within 1–2 working hours and answers anything — compatibility, install, alternatives.
+373 76 004 003Updated: · reviewed by CasaSmart Expert Team