Illuminance progress bar with background

Who it’s for

Building managers, facilities teams, and greenhouse growers ask “where does the current light level sit within our expected range?” They use this bar on dedicated building management or reception screens where a background image gives the card a polished look.

What it does

A sensor reading 35 lx fills the bar to 35% of the 0–100 lx scale and colors it red-orange — Bright — displayed over the preset background image. A reading of 2 lx fills only 2% in orange — Low.

• Horizontal progress bar that fills proportionally between the configured minimum and maximum
• Color-coded fill that changes across five illuminance bands from Dark to Very Bright
• Current value label shown alongside the bar
• Decorative background image bundled with the widget, with a white overlay that keeps the text readable
• Shows one sensor’s data; it does not chart trends or show a delta

How to set up

Data keys

Key	Role	Type	Description
illuminance	Bar 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.

If the key has never reported, the bar renders empty.

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 swap the background image — open the widget settings and set Background to a different image or switch to a solid color.
• To adjust how much the background shows through — change the Overlay opacity; lower values reveal more of the image, higher values push it further back.
• To match your sensor’s range — set Tick min and Tick max to the sensor’s minimum and maximum output; a sensor rated 0–1000 lx needs Tick max raised to 1000 so the bar fills correctly.
• To use your own illuminance thresholds — edit the color ranges; adjust the five default bands to match your application’s targets.
• To hide the value label — turn off Show value in the widget settings.
• To hide the entity name subtitle or the timestamp — turn off Show subtitle or Show date.

Tips

• The default scale is 0–100 lx, suited to low-level ambient monitoring. Raise Tick max to 500, 1000, or higher if your sensor covers a broader range; otherwise readings above 100 lx will peg the bar at 100%.
• If the background image reduces contrast, raise the Overlay opacity to keep the text readable from a distance.