Value Display
FREENumeric or text value from any topic
When to reach for it
Value Display reads one field from a topic by dot path and shows it as a number or a line of text: the generic fallback when nothing else fits. For a trend, use Sparkline or Time Series (both Pro).
For battery percentage, Battery Gauge handles the fill and color bands; for a full pose, Pose Display (Pro) reads all six numbers at once.
Worked example: battery voltage on a TurtleBot 4
TurtleBot 4's Create 3 base publishes sensor_msgs/msg/BatteryState on /battery_state. Set Topic there, Field Path voltage, Format Number, Unit V, Decimal Places 2. On Pro, set Alert Direction to Warn when below and set Warning and Critical Threshold to whatever voltage matters for your pack.
Watch out for
- Field Pathpointed at a struct doesn't show the struct. Number mode fails its type check and falls back to
--; Text mode stringifies the object and renders the literal[object Object]. Point it at a leaf value instead. - Warning Threshold and Critical Threshold both default to 0, and color coding only activates once one of them is nonzero: leave both alone and Alert Direction silently does nothing.
- Max Message Rate (Hz)defaults to 10, whatever the topic's real publish rate; extra messages are dropped before parsing. A fast IMU field will step visibly, not glide, until you raise it.
Configuration fields
The topic this widget reads from. While connected, tap to pick one the robot advertises.
Dot-path to the field to read, like pose.position.x. Blank uses the message's main value.
Messages per second this widget takes from the topic. Lower saves data, higher shows more.
0.1 to 60, step 0.1Which side of the threshold triggers a color change.
WITH PROChoose whether high or low values raise the alert, such as temperature or battery.
Value at which the display turns amber.
WITH PROText turns the warning color past this value, so you notice without reading the number.
Value at which the display turns red.
WITH PROText turns red and the border pulses past this value: your cue to check the robot.
Show the running minimum and maximum since the widget connected.
WITH PROSee peaks at a glance: min and max under the live value, reset on reconnect.
Text prepended to the value.
WITH PROAdd your own text before the value, such as "Pkg #".
Text appended to the value.
WITH PROAdd any text after the value, such as units the Unit list lacks.
Show a name on the widget.