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Zigbee devices Temperature and humidity sensors

EFEKTA SNZB-02_EFEKTA

Alternative firmware for the SONOFF SNZB-02 sensor from EfektaLab, DIY. Works with Zigbee2MQTT with no vendor hub or cloud: it pairs with a Zigbee stick and shows up in Home Assistant.

Vendor
EFEKTA
Model
SNZB-02_EFEKTA
Type
Temperature and humidity sensors
Power
battery: an end device, does not extend the mesh
Firmware updates (OTA)
no

Find it in shops: AliExpress

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What it exposes

FeaturePropertyValuesControl
Batterybattery% · 0…100read only
VoltagevoltagemVread only
Temperaturetemperature°Cread only
Humidityhumidity%read only
Sensor reading intervalsensor_reading_intervalsec. · 1…60settable
Enabling temperature controlenabling_temperature_control—settable
Temperature actionstemperature_actionsHEAT, COOLsettable
High temperaturehigh_temperature°C · -40…90settable
Low temperaturelow_temperature°C · -40…90settable
Enabling humidity controlenabling_humidity_control—settable
Humidity actionshumidity_actionsWET, DRYsettable
High humidityhigh_humidity% · 0…99settable
Low humiditylow_humidity% · 0…99settable

MQTT: state and commands

Zigbee2MQTT publishes the device state to zigbee2mqtt/my_device (my_device is the name you give the device). An example message:

{
  "battery": 87,
  "voltage": 2950,
  "temperature": 21.6,
  "humidity": 46.2,
  "sensor_reading_interval": 31,
  "enabling_temperature_control": false,
  "temperature_actions": "HEAT",
  "high_temperature": 25,
  "low_temperature": 25,
  "enabling_humidity_control": false,
  "humidity_actions": "WET",
  "high_humidity": 50,
  "low_humidity": 50,
  "linkquality": 120
}

Send commands to zigbee2mqtt/my_device/set:

mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"enabling_temperature_control":true}'
mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"temperature_actions":"COOL"}'
mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"enabling_humidity_control":true}'
mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"humidity_actions":"DRY"}'

Watch the topics live from the browser: MQTT client.

Home Assistant automation example

Zigbee2MQTT creates Home Assistant entities from the device name. If it is called my_device, an automation in automations.yaml can look like this:

- alias: "Room too warm"
  mode: single
  triggers:
    - trigger: numeric_state
      entity_id: sensor.my_device_temperature
      above: 26
      for: "00:10:00"
  actions:
    - action: notify.notify
      data:
        message: "Temperature above 26 °C"

Check the YAML: YAML checker.

How to pair it

  1. In Zigbee2MQTT click Permit join.
  2. Put the device in pairing mode: usually a long press of the reset button (5–10 s) until the LED blinks; bulbs: switch the power off and on 5–6 times.
  3. Keep the device close to the coordinator or a router while pairing.
  4. Give it a clear name: MQTT topics and Home Assistant entities are built from it.

Exact procedure and model notes: the device page in the Zigbee2MQTT docs. No coordinator yet: coordinator picker.

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