Progress Card

The progress card displays a value as a horizontal bar between a minimum and a maximum. Use it for fill levels, battery charge, task progress or any bounded quantity.

ConstructorCopy Anchor Link

dash::ProgressCard<T, Precision> card(dashboard, name, minValue, maxValue, unit);

Template parameters:

dash::ProgressCard progress(dashboard, "Progress", 0, 100, "%");       // int
dash::ProgressCard<float, 4> load(dashboard, "Load", 0, 1, "kWh");

An overload without the dashboard argument creates the card without attaching it to a dashboard; attach it later with dashboard.add(card).

MethodsCopy Anchor Link

setValue()Copy Anchor Link

bool setValue(const T& value);

Sets the value. Values below min() or above max() are clamped to the nearest bound. Returns true if the stored value changed.

value()Copy Anchor Link

const T& value() const;

Returns the current value. Call it only when hasValue() returns true.

hasValue()Copy Anchor Link

bool hasValue() const;

Returns true if a value has been set.

removeValue()Copy Anchor Link

bool removeValue();

Clears the value. The dashboard then shows 0. Returns true if a value was removed.

setMin()Copy Anchor Link

bool setMin(T minValue);

Sets the lower bound. If the current value is below the new bound, it is raised to the bound. Returns true if the bound changed.

setMax()Copy Anchor Link

bool setMax(T maxValue);

Sets the upper bound. If the current value is above the new bound, it is lowered to the bound. Returns true if the bound changed.

min() and max()Copy Anchor Link

T min() const;
T max() const;

Return the current lower and upper bounds.

setUnit()Copy Anchor Link

bool setUnit(const char* unit);

Sets the unit displayed next to the value. Returns true if the unit changed.

unit()Copy Anchor Link

const char* unit() const;

Returns the current unit.

ExampleCopy Anchor Link

#include <Arduino.h>
#include <WiFi.h>              // ESP32; use the networking headers for your board
#include <AsyncTCP.h>
#include <ESPAsyncWebServer.h>
#include <ESPDash.h>

AsyncWebServer server(80);
ESPDash dashboard(server);

dash::ProgressCard<int> tankLevel(dashboard, "Tank level", 0, 100, "%");

void setup() {
  // ... connect to Wi-Fi
  server.begin();
}

void loop() {
  int level = random(0, 101); // replace with a sensor reading
  tankLevel.setValue(level);
  dashboard.sendUpdates();
  delay(3000);
}

NotesCopy Anchor Link

• The card stores the unit pointer and does not copy the string. Pass a string literal or a buffer that outlives the card.