Illuminance Sensor

Estimates outdoor illuminance based on either sun elevation or time of day. In either case, the value is adjusted based on current weather conditions.

Modes of operation

Two modes are available: normal & simple. The desired mode is selected via the configuration.

Normal mode - Sun elevation

This mode uses an algorithm from the US Naval Observatory[^1] for estimating sun illuminance based on the sun's elevation (aka altitude.) The maximum value is about 150,000 lx. Below is an example of what that might look like over a three day period.

[^1]: Janiczek, P. M., and DeYoung, J. A. Computer Programs for Sun and Moon Illuminance With Contingent Tables and Diagrams. Circular No. 171. Washington, D. C.: United States Naval Observatory, 1987 Google Scholar

Simple mode - Time of day

At night the value is 10 lx. From a little before sunrise to a little after the value is ramped up to whatever the current conditions indicate. The same happens around sunset, except the value is ramped down. The maximum value is 10,000 lx. Below is an example of what that might look like over a three day period.

Supported weather sources

The following sources of weather data are supported:

• Dark Sky Sensor (icon)
• Dark Sky Weather
• Meteorologisk institutt (Met.no)
• AccuWeather
• ecobee
• OpenWeatherMap

Setup

Follow the installation instructions below. Then add the desired configuration. Here is an example of a typical configuration:

sensor:
  - platform: illuminance
    entity_id: weather.home

Installation

Manual

Place a copy of:

__init__.py at <config>/custom_components/illuminance/__init__.py
sensor.py at <config>/custom_components/illuminance/sensor.py
manifest.json at <config>/custom_components/illuminance/manifest.json

where <config> is your Home Assistant configuration directory.

NOTE: Do not download the file by using the link above directly. Rather, click on it, then on the page that comes up use the Raw button.

With HACS

You can use HACS to manage installation and updates by adding this repo as a custom repository and then searching for and installing the "Illuminance" integration.

Configuration variables

• entity_id: Entity ID of entity that indicates current weather conditions. See examples below.
• mode (Optional): Mode of operation. Choices are normal (default) which uses sun elevation, and simple which uses time of day.
• name (Optional): Name of the sensor. Default is Illuminance.
• scan_interval (Optional): Update interval. Minimum is 5 minutes. Default is 5 minutes.

Examples

Dark Sky Sensor

sensor:
  - platform: darksky
    api_key: !secret ds_api_key
    monitored_conditions:
      - icon
  - platform: illuminance
    name: DSS Illuminance
    entity_id: sensor.dark_sky_icon

Dark Sky Weather

weather:
  - platform: darksky
    api_key: !secret ds_api_key
sensor:
  - platform: illuminance
    name: DSW Illuminance
    entity_id: weather.dark_sky

Met.no, AccuWeather or ecobee

sensor:
  - platform: illuminance
    name: Estimated Illuminance
    entity_id: weather.home

OpenWeatherMap

sensor:
  - platform: illuminance
    name: Estimated Illuminance
    entity_id: weather.openweathermap

Releases Before 2.1.0

See https://github.com/pnbruckner/homeassistant-config/blob/master/docs/illuminance.md.