Built-in Temperature Sensor Shelly Plus Add-On — wired indoor/outdoor sensor, -20–40°C, 37×42×15 mm

The Shelly Plus Add-On is a compact, galvanically isolated sensor interface designed for use with Shelly Plus relays. Measuring 37 × 42 × 15 mm, it supports 1-Wire temperature sensors and a variety of analog and digital sensors for both indoor and outdoor monitoring. The Add-On enables precise measurement of temperature and humidity and expands relay capabilities to create complex automation scenes.

Advantages

Galvanic isolation ensures safe sensor connections to Shelly Plus relays. The module is compatible with most Arduino sensors and accepts analog, digital and 1-Wire inputs for flexible integration. Its small built-in form factor makes it suitable for concealed installation while providing reliable monitoring for temperature, humidity, luminosity, motion, liquid level, soil moisture and door position sensors.

Suitable for

• Temperature and humidity monitoring with DS18B20 or similar 1-Wire sensors
• Light-based automation using LDR/photoresistor
• Garage door or window position detection with reed-switch sensors
• Liquid level sensing for aquariums or tanks
• Soil moisture-based irrigation control
• Motion-activated lighting with PIR sensors

Key specifications

• Manufacturer: Shelly
• Model / MPN: ALL_SHELLY_PLUS_ADD-ON
• EAN: 3800235266427
• Dimensions: 37 × 42 × 15 mm (W × D × H)
• Interface: 1-Wire plus analog and digital inputs
• Compatibility: Works with Shelly Plus relays and most Arduino-compatible sensors

How to use

Connect the Shelly Plus Add-On to a Shelly Plus relay following the relay’s wiring diagram. Attach 1-Wire sensors such as DS18B20 to the 1-Wire terminals for temperature measurement, or connect analog/digital sensors (LDR, PIR, reed-switch, soil moisture, liquid level, wind or rain sensors) to the corresponding inputs. Configure sensor types and triggers in the Shelly Plus relay firmware or companion app to create automation scenes that respond to measured values.

Recommendations

The Shelly Plus Add-On is intended for built-in installations; for outdoor mounting ensure sensors and any exposed connections have appropriate weather protection. Use galvanic isolation to reduce electrical interference and follow recommended wiring lengths for 1-Wire sensors to maintain measurement accuracy.