Arduino Button Library

//Button.h

/*
    Button - a small library for Arduino to handle button debouncing

    MIT licensed.
*/

#ifndef Button_h
#define Button_h
#include "Arduino.h"

class Button
{
    public:
        Button(uint8_t pin, bool pressed);
        void begin();
        bool read();
        bool toggled();
        bool pressed();
        bool released();
        bool has_changed();

        const static bool PRESSED = LOW;
        const static bool RELEASED = HIGH;

    private:
        uint8_t  _pin;
        uint16_t _delay;
        bool     _state;
        bool     _has_changed;
        uint32_t _ignore_until;
};

#endif

////////////////////////////////////////////////////////////////////////////////

//Button.cpp

/*
    Button - a small library for Arduino to handle button debouncing

    MIT licensed.
*/

#include "Button.h"
#include <Arduino.h>

Button::Button(uint8_t pin, bool pressed)
:  _pin(pin)
,  _delay(100)
,  _state(HIGH)
,  _has_changed(false)
,  _ignore_until(0)
{
}

void Button::begin()
{
    pinMode(_pin, INPUT_PULLUP);
}

//
// public methods
//

bool Button::read()
{
    // ignore pin changes until after this delay time
    if (_ignore_until > millis())
    {
        // ignore any changes during this period
    }

    // pin has changed
    else if (digitalRead(_pin) != _state)
    {
        _ignore_until = millis() + _delay;
        _state = !_state;
        _has_changed = true;
    }

    return _state;
}

// has the button been toggled from on -> off, or vice versa
bool Button::toggled()
{
    read();
    return has_changed();
}

// mostly internal, tells you if a button has changed after calling the read() function
bool Button::has_changed()
{
    if (_has_changed == true)
    {
        _has_changed = false;
        return true;
    }
    return false;
}

// has the button gone from off -> on
bool Button::pressed()
{
    if (read() == PRESSED && has_changed() == true)
        return true;
    else
        return false;
}

// has the button gone from on -> off
bool Button::released()
{
    if (read() == RELEASED && has_changed() == true)
        return true;
    else
        return false;
}