Zigbee Motion Sensor 4-in-1
Zigbee Motion Sensor 4-in-1 — side view
Zigbee Motion Sensor 4-in-1 — detail view

Zigbee Motion Sensor 4-in-1 — Temperature, Humidity, Home Assistant compatible

(2 customer reviews)

£24.99

Zigbee motion sensor – ultimate multi sensor with motion, occupancy, temperature, humidity & lux functionalities, all in one device. Battery-powered, wall or freestanding, works with Home Assistant.

In stock

SKU: SM321 Categories: , , Tags: , , , ,

Description

Ultimate integration of smart sensing technology for your home. This state-of-the-art device is not just a sensor, but a comprehensive monitoring system packed into one sleek unit that seamlessly integrates with Home Assistant, making it a perfect addition to your smart home. Our Multi Sensor can be either wall mounted on a standard UK/EU socket or used as a standalone device once detached from the accompanying frame.

  • Motion: Detects movement with precision, ensuring your home’s security and automation needs are met.
  • Occupancy: Understands room occupancy, optimizing energy usage and enhancing comfort.
  • Temperature: Monitors ambient temperature, ensuring your living spaces are always at the ideal warmth.
  • Humidity: Keeps track of moisture levels, perfect for maintaining optimal room conditions.
  • Illumination: Measures light intensity, allowing for perfect ambiance setting and energy savings.
  • Battery-Powered: Operates on just 2 x AA batteries, ensuring longevity and ease of use.
  • Low Power Consumption: Designed for efficiency, it ensures minimal battery drain and a longer device lifespan.

COMPATIBILITY:
Home Assistant

Package contains:
SM321 Zigbee Multi Sensor
2 x AAA batteries
3M adhesive & Manual

Note: PIR motion sensors can be triggered by other sources of infrared radiation, such as direct sunlight or heaters, so it’s important to properly position and test the sensor to avoid false alarms.

Additional information

Weight 100 g
Brand

Samotech

Frequently Asked Questions

What does the SM321 4-in-1 Zigbee Sensor measure?

The SM321 is an all-in-one monitoring device that measures five things in one unit: motion (PIR), room occupancy, ambient temperature, humidity, and illumination (lux). All readings are exposed to your smart home platform individually.

Where can I install the SM321?

The SM321 can be wall-mounted on a standard UK/EU socket using the included frame and 3M adhesive, or detached from the frame and used as a standalone unit on a shelf or table. Avoid pointing the PIR directly at heaters, vents, or direct sunlight to prevent false triggers.

What batteries does the SM321 use?

The SM321 ships with 2 × AAA batteries included in the box. Low power consumption means battery life is extended.

Which platform is the SM321 compatible with?

The SM321 uses Zigbee 3.0 and integrates with Home Assistant via any compatible Zigbee hub or coordinator.

How do I avoid false motion triggers?

PIR motion sensors respond to changes in infrared radiation. Position the sensor so it doesn’t face direct sunlight, heaters, radiators, or other heat sources. Test the placement after installation to confirm reliable detection without false alarms.

Alexa can’t find my SM321 sensor — what should I check?

Make sure you have an Alexa-compatible Echo device. After adding a new device, check your full device list directly — Alexa may show "No new devices found" even after a successful add. If still missing, reset the sensor and re-add it.

My SM321 sensor stopped working in Alexa — how do I fix it?

After a major Alexa app update, sensors sometimes need re-pairing. Reset the sensor and re-add it to Alexa. Critically — remove the old sensor entry from Alexa’s device list before re-adding it, otherwise the new pairing may conflict with the stale entry.

My "Lights Off" Alexa routine has stopped working with the SM321 — how do I fix it?

After Alexa app updates, delayed-action routines can break. Delete the old action, then add a Wait action for your required delay (e.g. 5 minutes) followed by a Time action of 0 minutes. The Lights Off routine will then trigger after the wait period as expected. Note: motion detection is pre-set to one trigger per 60 seconds.

VIDEO

Manual

SM301Z Zigbee PIR Manual

2 reviews for Zigbee Motion Sensor 4-in-1 — Temperature, Humidity, Home Assistant compatible

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  1. Antony
    Verified owner
    (0) (0)
  2. Saheed C.
    Verified owner

    Great to have a few more features in the same sensor

    (0) (0)
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