Air Card

This feature is only available in ESP-DASH Pro

The Air Card displays atmospheric pressure values.

Initializer

To create an air card in ESP-DASH v5, use the dash::AirCard<T, Precision> class. The template parameters allow you to control the value type and decimal precision:

• T: Value type (e.g., float, int)
• Precision: Number of decimal places for floating point values (default: 2)

Example 1: Float value, default precision (2 decimals)

dash::AirCard<float> air(dashboard, "Pressure");

Example 2: Float value, custom precision (3 decimals)

dash::AirCard<float, 3> air3(dashboard, "Pressure", "kPa");

Example 3: Integer value

dash::AirCard<int> airInt(dashboard, "Pressure", "Pa");

Methods

setValue(T value)

Set the air quality value. The type of value must match the template type you chose for T (e.g., int, float).

air.setValue(value); // value is of type T

• Signature: void setValue(T value)
• Parameters:
  • T value — The value to display (type matches template parameter T).
• Returns: void

value()

Get the current air quality value. The return type matches your template type for T (e.g., int, float).

T v = air.value();

• Signature: T value()
• Parameters: None
• Returns: T — The current value displayed by the card (type matches template parameter T).

Note:

• T can be one of: int or float depending on how you instantiate the card.

setUnit(const char* unit)

Set the unit or symbol for the air card (e.g., “hPa”, “kPa”).

air.setUnit("kPa");

• Signature: void setUnit(const char* unit)
• Parameters:
  • const char* unit — The unit or symbol to display.
• Returns: void

unit()

Get the current unit or symbol for the air card.

const char* unit = air.unit();

• Signature: const char* unit()
• Parameters: None
• Returns: const char* — The current unit or symbol for the card.

Reference

Below is a reference code showing how to integrate this widget in a real project, including initialization and value updates usage.

// ...
 
// Create an air card (float, 2 decimals by default)
dash::AirCard<float> airCard(dashboard, "Pressure", "hPa");
 
void setup() {
  // ...
  
  airCard.setValue(1013.25f);
  airCard.setUnit("hPa");
}
 
void loop() {
  // ...
}