Pressure chart card with background
Who it’s for
Meteorologists, weather station operators, and building managers ask “how has pressure changed over the selected period?” They want the trend and delta in one card displayed over a background image for dedicated weather monitoring or reception screens.
What it does
A sensor averaging 1008 hPa this period versus 1018 hPa last period shows a green value — Normal — with a -1% delta and a -10 hPa absolute change, indicating falling pressure, displayed over the preset background image.
- Large current pressure value color-coded across three bands: Low (red), Normal (green), High (red)
- Delta percentage and absolute delta comparing the current period to the previous one
- Time-series chart of pressure readings averaged per interval
- Decorative background image bundled with the widget, with a white overlay that keeps the text readable
- Shows one sensor’s data; it does not compare multiple stations
How to set up
Data keys
| Key | Role | Type | Description |
|---|---|---|---|
pressure | Chart series | Timeseries | Atmospheric pressure in hPa; drives the chart and all derived overlays |
| Latest | Latest value | Timeseries | The headline figure above the chart. Its own color ranges are where the band colors are edited |
| Delta percent | Percentage change | Timeseries | Change against the previous period, as a percentage |
| Delta absolute | Absolute change | Timeseries | Change against the previous period, in the key’s own unit |
The widget ships with a simulated function datasource key labeled Pressure, 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 for the selected time window, the chart is empty and all overlays show no data.
Value ranges
| Range (hPa) | Level | Color |
|---|---|---|
| < 1000 | Low | Red |
| 1000–1020 | Normal | Green |
| > 1020 | High | 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 use your own pressure thresholds — edit the color ranges on the Latest data key; adjust the three default bands to match your operational limits.
- To change the comparison period — adjust the Time window on the dashboard; the delta automatically compares to the equivalent preceding period.
- To hide or show the chart — toggle Show chart in the widget settings.
- To change the chart line color — set Chart color.
- To hide the entity name subtitle or the timestamp — turn off Show subtitle or Show date.
Tips
- A fall of 8–10 hPa over 3 hours is a strong indicator of an approaching storm — the chart’s slope is more actionable than the instantaneous value.
- If the background image reduces contrast, raise the Overlay opacity to keep the text readable from a distance.
Share Your Widget with the Community
Built a custom widget? Export it as a JSON from ThingsBoard and publish it to the IoT Hub through a simple 4-step wizard (Upload, Listing, Readme, Review & Submit). Share it with thousands of ThingsBoard developers worldwide and get featured in the catalog.