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Signal Strength

Signal strength widget

The Signal strength widget displays the current wireless signal level as a Wi-Fi arc or cellular bar icon, with the active bars colored to reflect signal quality. Use it on device monitoring dashboards to visualize connectivity strength at a glance — without reading raw dBm values.

  • Two icon styles: Wi-Fi (arc) and Cellular bar — choose the one that matches the device’s radio technology.
  • Active signal bars color with four modes — constant, gradient, value range segments, or a JavaScript function — for threshold-based coloring without custom code.
  • Independently configurable inactive bars color.
  • Optional hover tooltip showing the raw value with unit (e.g., dBm) and last-update timestamp.
  • Optional date label on the card face showing how long ago the last reading arrived.
  • On card click and Widget header button actions.
  1. Open the dashboard in edit mode. Click Add widget in the top toolbar, or click the Add new widget icon in the center of an empty dashboard.
  2. In the widget bundle selection dialog, find and click Status indicators.
  3. Select the Signal strength widget.
  4. Configure the datasource and appearance, then click Add.

All settings are on the Basic tab. Switch to Advanced for card-level controls — title font, tooltip, border radius, and CSS overrides.

Select the source of the signal level value:

  • Device — a specific device; the widget reads the latest value from this device.
  • Entity alias — a set of entities matched by an entity alias; use when the target device is selected dynamically at runtime.

Add exactly one data key — a telemetry key or attribute — whose numeric value represents the signal strength (typically a negative dBm value such as rssi or rssl).

LayoutDescription
Wi-FiDisplays a Wi-Fi arc icon. Use for Wi-Fi connected devices. Default.
Cellular barDisplays vertical cellular signal bars. Use for cellular (2G/3G/4G/LTE) devices.
SettingDescription
TitleLabel shown on the card. Enabled by default, value Signal strength. Supports {x} dynamic placeholders: entityName and entityLabel. Configure font and color independently.

An optional icon placed on the card. Disabled by default. Configure size (px) and color when enabled.

An optional line on the card showing when the last data value arrived.

SettingDescription
DateToggle to show or hide the last-update timestamp on the card face.
Date formatFormat of the displayed date. Default: Last update N ago.
SettingDescription
Active signal bars colorColor of the filled (active) bars. Supports four color modes — see below.
Inactive signal bars colorColor of the unfilled (inactive) bars. Grey by default.
ModeDescription
ConstantSingle fixed color for all active bars.
GradientColor transitions smoothly across the value range. Configure start and end values and color stops.
RangeAssigns a specific color to each value segment. Add multiple From / To rows for threshold-based coloring — for example, green for strong signal (−55 to 0 dBm), yellow for moderate (−75 to −55 dBm), red for weak (below −75 dBm).
FunctionA JavaScript function f(value) that returns a CSS color string. Use for custom or non-linear coloring logic.

A tooltip shown when the user hovers over the widget, displaying the raw value and the time of the last update.

SettingDescription
ValueToggle to show or hide the raw value in the tooltip. Enabled by default.
UnitUnit suffix appended to the displayed value. Default: dBm.
DecimalsNumber of decimal places. Default: 0.
SettingDescription
DateToggle to show or hide the last-update timestamp in the tooltip. Enabled by default.
Date formatFormat of the date shown in the tooltip. Default: Last update N ago.
SettingDescription
Background colorTooltip background fill. Empty by default.
Background blurBlur radius applied to the tooltip background. Default: 3px.
SettingDefaultDescription
BackgroundCard background color.
Show card buttonsToggle Data export and Fullscreen buttons in the widget header.
Card border radius0pxCorner rounding.
Card padding12pxSpacing between card content and its border.
SourceDescription
On card clickTriggers a configured action when the user clicks anywhere on the widget card.
Widget header buttonAdds a custom button to the widget header that triggers a configured action when clicked.

Goal: Monitor the wireless signal quality of IoT gateways deployed across multiple sites, with the icon changing color based on connection strength.

Prerequisites: Gateways reporting rssi (dBm, typically −30 to −90) as a telemetry key.

Step 1. Add the widget. Open your dashboard in edit mode, click Add widget, select Status indicators, then choose Signal strength.

Step 2. Configure the datasource. Set Datasource type to Entity alias, select an alias that resolves to your gateways, and add rssi as the data key.

Step 3. Set the layout. In Appearance, set Layout to Wi-Fi for Wi-Fi gateways, or Cellular bar for cellular modems.

Step 4. Configure threshold colors. Click Active signal bars color, select Range mode, then add three segments:

FromToColor
−75Red
−75−55Yellow
−55Green

Step 5. Configure the tooltip. In the Tooltip section, set Unit to dBm and leave Date enabled so operators can see when the last reading arrived.

Step 6. Save. Click Add, arrange the widget, then save the dashboard.

Result: Each gateway card shows a signal icon that colors green for strong connections, yellow for moderate, and red for weak — with the exact dBm value available on hover.

Icon shows no active bars

CauseSolution
No data receivedOpen Devices → Latest telemetry and verify the device reports the configured data key. Key names are case-sensitive.
Value is null or non-numericEnsure the device sends a numeric value for the configured key.
Entity alias resolves to no entitiesOpen Entity aliases in the dashboard and verify the alias returns results.

Active bar color does not change with value

CauseSolution
Active signal bars color set to ConstantSwitch to Gradient, Range, or Function mode for value-dependent coloring.
Range segments don’t cover the actual value rangeSignal strength values are typically negative (e.g., −90 to −30 dBm). Verify your From / To range rows match the expected value range.

Tooltip does not appear

CauseSolution
Tooltip toggle is offEnable the Tooltip toggle in the Appearance section.
Both Value and Date toggles are offEnable at least one of Value or Date inside the Tooltip section.