homebridge-netatmo-weather

A Homebridge plugin that brings your Netatmo Weather Station into HomeKit via the Netatmo cloud, so your accessories don't need to live on the same VLAN as your iPhone.

Exposes four accessories from a single local weather endpoint (five if you configure a second indoor module):

1. Indoor module — temperature, humidity, CO₂ (with a CarbonDioxideDetected flag that trips above a configurable threshold, default 1500 ppm).
2. Outdoor module — temperature, humidity.
3. CO₂ Alert — standalone MotionSensor accessory whose motion flips on/off in lockstep with the indoor CO₂ ABNORMAL state. Enables iOS Home automations in both directions ("CO₂ went high → notify, open window" AND "CO₂ went back down → all clear"), which a single CarbonDioxideDetected characteristic can't trigger on its own.
4. Blinds recommendation (light sensor) — a synthetic lux value (blind_lux) pre-computed by the upstream weather endpoint, useful for automations like "close the blinds when the sun gets direct."
5. Bedroom module (optional, 1.8.0+) — second indoor module accessory (temp + humidity + CO₂), registered only when the upstream weather endpoint emits a bedroom block. Intended for an NIM01-WW Smart Indoor Air Quality Monitor placed elsewhere.

The data path is:

Netatmo cloud  →  your weather endpoint (eg. netatmo-scanner)  →  this plugin  →  HomeKit

No device-to-iPhone LAN reachability is required — which matters if you've isolated Netatmo devices on their own IoT VLAN.

Why cloud-fed instead of the native HomeKit pairing

Netatmo Weather Stations ship with a native HomeKit pairing that talks IP-direct between the device and your iPhone. If you put the device on an isolated IoT VLAN, that direct path breaks (Keine Antwort / No Response) unless you add an mDNS reflector and cross-VLAN firewall holes. This plugin avoids that entirely — all communication flows through Homebridge, which you can host on the same VLAN as your iPhone.

Configuration

| Field | Type | Default | Description | |-------|------|---------|-------------| | weatherEndpoint | string | required | URL of the weather API endpoint | | pollInterval | number | 60 | Polling interval in seconds | | name | string | "Netatmo Weather" | Display name of the light-sensor accessory | | indoorName | string | "Netatmo Indoor" | Display name of the indoor module accessory | | outdoorName | string | "Netatmo Outdoor" | Display name of the outdoor module accessory | | bedroomName | string | "Netatmo Bedroom" | Display name of the optional bedroom indoor module accessory. Only registered when the upstream emits a bedroom block. | | co2AbnormalAt | number | 1500 | ppm threshold above which CO₂ accumulates toward ABNORMAL. Raised from the ASHRAE 1000 ppm guideline because Netatmo's raw /getmeasure CO₂ values run ~4× higher than what the Netatmo iOS app displays. Tune lower if your sensor is well-calibrated. | | co2NormalAt | number | 1200 | ppm threshold below which CO₂ accumulates toward NORMAL. The gap between co2NormalAt and co2AbnormalAt forms a hysteresis band where the prior state is held. | | co2AbnormalSamples | number | 3 | Consecutive polls past the threshold required before flipping CarbonDioxideDetected. Suppresses single-poll spikes. | | debugPort | number | unset | If set, exposes a 127.0.0.1-only HTTP endpoint for forcing lux values (POST /lux?value=N). Leave empty to disable. |

Example config

{
  "platform": "NetatmoWeather",
  "name": "Netatmo Weather",
  "indoorName": "Office",
  "outdoorName": "Loggia",
  "bedroomName": "Bedroom",
  "weatherEndpoint": "http://192.168.1.123:8087/weather",
  "pollInterval": 60,
  "co2AbnormalAt": 1500,
  "co2NormalAt": 1200,
  "co2AbnormalSamples": 3
}

Expected weather-endpoint response shape

{
  "weather_today": "Sunny",
  "blind_lux": 20,
  "lux": 1,
  "current": {
    "temperature": 19.1,
    "humidity": 45,
    "pressure": 1014
  },
  "indoor": {
    "temperature": 25.5,
    "humidity": 41,
    "co2": 551,
    "noise": 38
  },
  "bedroom": {
    "temperature": 21.8,
    "humidity": 52,
    "co2": 720
  }
}

Fields inside current.*, indoor.*, and bedroom.* are optional — a missing value for a given sensor just skips that HomeKit update on that poll. Omit the bedroom block entirely if you don't have a second indoor module; the bedroom accessory simply won't register.

Blinds-recommendation lux values

The blind_lux field encodes a pre-computed blinds strategy rather than actual ambient light:

| Lux | Condition | Blinds action | HomeKit trigger | |-----|-----------|---------------|-----------------| | 0 | No sun expected | Open blinds | — | | 20 | Sunny + cool | Tilt to 60% | > 10 lux | | 200 | Sunny + hot | Full sun protection | > 100 lux |

HomeKit automation example

• Lux ≥ 200 → Close blinds fully (sun protection)
• Lux ≥ 20 → Tilt blinds to 60% (let warmth in)
• Lux < 20 → Open blinds fully
• CO₂ > co2AbnormalAt → Notify to open a window (use the CO₂ Alert MotionSensor to also trigger an "all clear" automation when CO₂ drops back below co2NormalAt).