Doughnut Display
Visualize a sensor reading as a proportional ring with the Doughnut display in the Last Data widget — ideal for %.
The Doughnut display draws the reading as a ring that fills proportionally between a minimum and a maximum you define, with the current value in the center. At a glance it answers "how far along is this?" — a quarter full, nearly maxed out — without anyone reading the number.
It suits any reading that lives inside a known range: a fill level, a percentage, a capacity, a value that should sit somewhere within an operating band. The ring's fill makes the position in that range immediate.
When to choose it
A reading with a defined operating range where the proportion matters — tank capacity, battery charge, utilization against a limit.
A dashboard tile where an operator should register low / mid / high in a glance, not parse digits.
Anywhere a percentage or ratio reads more clearly as a filled ring than as a figure.
Wherever a reading has a meaningful floor and ceiling, the Doughnut turns it into a shape — let your own metrics suggest where it fits.
Configure a Doughnut display
Here is a full setup for one real case — a ring that shows an office's temperature and whether it is comfortable. A temperature sensor reports the room in °C. A temperature is unlike a tank — it has no natural "empty" or "full", so there is no obvious 0 and 100. The ring still needs a floor and a ceiling, so you pick a window wide enough to hold every temperature the room could realistically reach: for a house room, about -5 °C to +40 °C. This is one example: a Doughnut suits any reading you want to see as a proportion of a range — only the device and the numbers change.
Open the dashboard in edit mode and click Last data in the widget picker. The settings panel opens on the Datasource tab, with no data sources yet.
Click Add datasource. A Datasource 1 block appears.
In the block, click Choose device and select the temperature sensor.
Click Add metric. A metric row appears.
In the row, set Data type to Telemetry, choose the temperature reading under Device metric, and pick an Icon.
This display needs a number. The Device metric list offers every metric type, but a gauge fills against a scale — pick a numeric reading here; a non-numeric text value reads as 0. (To show text or an on/off value as-is, use the Value display.) To change how a metric is stored, open Devices → Metrics — see Metrics.
Click Conditions: N to open the Conditions modal. Set a Default color — the color the reading falls back to whenever none of your conditions match the current value — then for each band click Add condition and fill the row — enter a Condition name, set Data type to Number (the condition's own Data type, not the metric row's), because a house room realistically swings between -5 °C and 40 °C, enter From -5 (the coldest you would expect) and To 40 (the hottest), and pick a Color. Then you can enter the color levels. For example:
Working up from the coldest:
"Too cold" — From -5, To 15 — red
"Cool" — From 15, To 18 — yellow
"Comfortable" — From 18, To 24 — green
"Warm" — From 24, To 28 — yellow
"Too hot" — From 28, To 40 — red
Click Save to close the modal.
Click Next to open the Appearance tab.
Enter a Widget name — for example "Office temperature" — and an optional Description.
Under Widget type, choose Doughnut. A Value range section appears for the metric.
Set Min value to -5 and Max value to 40 — the window you chose for a house room. The ring fills to show where the current temperature sits across that -5–40 °C span, and the condition the reading falls in colors it.
Switch on Display data legend if useful, then click Save.
The ring shows the temperature as a position in the chosen range and turns green only inside the comfortable band. The same steps fit any reading with a sensible floor and ceiling — only the device, the Min value/Max value, and the conditions change. A Doughnut earns its place when "how far through the range" is the question; for a temperature you simply want to read off, a Number or Gauge is often the more natural display.
Worked examples
The same sensor, a completely different setup — a refrigerator A refrigerator uses the same kind of temperature sensor as the office above, yet every number is different — because the right window depends on what you are measuring. A fridge's safe band is roughly 0–5 °C, so you set the scale a little wider than that band, so a fridge that fails and warms up still shows on the ring: Min value -5, Max value 15. Then build three conditions: "Too cold" — From -5, To 0 — blue; "Safe" — From 0, To 5 — green; "Too warm" — From 5, To 15 — red. Identical hardware, identical steps — only the window and the bands change, because "good" means something completely different in a fridge than in an office. That is the heart of conditions: you decide what each reading means in its own context.
A fill level A Doughnut is a natural fit for a tank or a battery. A level sensor in a 5,000-liter tank reports the contents in liters, so 0 L is an empty tank and 5,000 L is full — Min value 0, Max value 5000 — with conditions green From 3000 To 5000, yellow From 1000 To 3000, red From 0 To 1000. The ring empties visibly as the tank is drawn down.
See also
Last Data Widget — Full setup reference and the other display types
Conditions — Numeric From/To color rules for each metric
Other display types: Value · Pie · Gauge · Tube · Radial gauge
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