What it exposes
| Feature | Property | Values | Control |
|---|---|---|---|
| CO₂ | co2 | ppm | read only |
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:
{
"co2": 640,
"linkquality": 120
}
The device only reports data and takes no commands.
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: "Time to ventilate"
mode: single
triggers:
- trigger: numeric_state
entity_id: sensor.my_device_co2
above: 1000
actions:
- action: notify.notify
data:
message: "CO₂ above 1000 ppm, open a window"
Check the YAML: YAML checker.
How to pair it
- In Zigbee2MQTT click Permit join.
- 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.
- Keep the device close to the coordinator or a router while pairing.
- 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.