Illuminance card

Who it’s for

Building managers, facilities teams, and greenhouse growers ask “is the light level adequate right now?” They need a single at-a-glance card that confirms whether a space is properly lit or dangerously dark without digging into charts.

What it does

A sensor reading 8 lx shows an orange icon and value — Moderate — telling you the space has some light but far below working levels. The same card turns red at 35 lx — Bright — and dark gray at 0.5 lx — Dark.

• Color-coded icon and value that shift across five illuminance bands from Dark to Very Bright
• Last-updated timestamp showing how long ago the reading arrived
• Shows one sensor’s data; it does not chart trends or compare multiple zones

How to set up

Data keys

Key	Role	Type	Description
illuminance	Main value	Timeseries	Illuminance in lx; change the key name to match your device’s telemetry key

The widget ships with a simulated function datasource key labeled Illuminance, so it draws random values until you point the datasource at a device and rename the key.

To point it at your own device: open the dashboard in edit mode, open the widget’s Datasources, pick the entity or entity alias, and replace the function key with the key your device reports.

The card shows the value in lx with no decimal places. If the key has never reported, the card displays the label and icon with an empty value, not an error.

Value ranges

Range (lx)	Level	Color
< 1	Dark	Dark Gray
1–5	Low	Orange
5–20	Moderate	Orange
20–50	Bright	Red-Orange
50+	Very Bright	Red

How to customize

• To use your own illuminance thresholds — edit Icon color ranges and Value color ranges; set the same boundaries in both so the icon and the number always agree.
• To change the icon — set Icon to any Material or MDI icon name.
• To hide the label, icon, or timestamp — turn off Show label, Show icon, or Show date.
• To switch to an absolute timestamp — turn off Last update ago in the date format settings.
• To match your dashboard’s fonts — set Value font and Label font.

Tips

• Keep Icon color ranges and Value color ranges on the same boundaries so the icon and the number always show the same band.
• Typical working-plane targets: offices 300–500 lx, warehouses 100–200 lx, plant grow lights 10000+ lx. The default five-band scale suits ambient monitoring; adjust thresholds for your specific application.