Command & Toggle

This is a basic example, it will show you how to use callback functions in the LcdMenu library.

Callbacks can be used with menu items of type ItemCommand, ItemInput, ItemList, ItemProgress or ItemToggle


// other includes ...
#include <ItemToggle.h>
#include <LcdMenu.h> // Always comes after every item type import

Declare the callback function

// For ItemToggle
void myCallbackFunction(uint16_t isOn);
// For ItemCommand
void myCallbackFunction();

Add a callback to MenuItem

    ITEM_BASIC("Start service"),
    ITEM_BASIC("Connect to WiFi"),
    // Include callback in ItemToggle
    ITEM_TOGGLE("Backlight", myCallbackFunction),
    ITEM_BASIC("Blink SOS"),
    ITEM_BASIC("Blink random")

Define the callback function

When enter() is invoked, the command (callback) bound to the item is invoked.

 * Define the callback function
void myCallbackFunction(uint16_t isOn) {

Constructor reference

ItemCommand(const char* key, fptr callback)
ItemToggle(const char* key, fptrInt callback)
ItemToggle(const char* key, const char* textOn, const char* textOff, fptrInt callback)
  • key: display text of the item

  • textOn: display text when ON

  • textOff: display text when OFF

  • callback: reference to a callback function

Full code 👉 .../examples/Callbacks/Callbacks.ino

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