AH::Button Class Reference

A class for reading and debouncing buttons and switches. More...

#include <Button.hpp>

Collaboration diagram for AH::Button:

Public Types
enum	State { Pressed = 0b00, Released = 0b11, Falling = 0b10, Rising = 0b01 }
	An enumeration of the different states a button can be in. More...

Public Member Functions
	Button ()
	Construct a new Button object. More...
	Button (pin_t pin)
	Construct a new Button object. More...
void	begin ()
	Initialize (enable the internal pull-up resistor). More...
AH_INDIVIDUAL_BUTTON_INVERT_STATIC void	invert ()
	Invert the state of all buttons, or of this specific button (button pressed is HIGH instead of LOW). More...
State	update ()
	Read the button and return its new state. More...
State	getState () const
	Get the state of the button, without updating it. More...
unsigned long	previousBounceTime () const
	Return the time point (in milliseconds) when the button last bounced. More...
unsigned long	stableTime (unsigned long now) const
	Return the time (in milliseconds) that the button has been stable for, compared to the given time point. More...
unsigned long	stableTime () const
	Return the time (in milliseconds) that the button has been stable for. More...

Static Public Member Functions
static const __FlashStringHelper *	getName (State state)
	Return the name of the state as a string. More...

Private Attributes
pin_t	pin
bool	prevInput = HIGH
State	debouncedState = Released
unsigned long	prevBounceTime = 0

Static Private Attributes
static bool	invertState = false
constexpr static unsigned long	debounceTime = BUTTON_DEBOUNCE_TIME
	Edit this in Settings.hpp. More...

Detailed Description

A class for reading and debouncing buttons and switches.

Definition at line 18 of file Button.hpp.

Member Enumeration Documentation

State

enum AH::Button::State

An enumeration of the different states a button can be in.

Enumerator
Pressed
Released	< Input went from low to low (0,0)
Falling	< Input went from high to high (1,1)
Rising	< Input went from high to low (1,0)

Definition at line 53 of file Button.hpp.

Constructor & Destructor Documentation

Button() [1/2]

AH::Button::Button ( )

inline

Construct a new Button object.

This constructor should not be used.
It is just a way to easily create arrays of buttons, and initializing them later.

Definition at line 27 of file Button.hpp.

Button() [2/2]

AH::Button::Button

(

pin_t

pin

)

Construct a new Button object.

Parameters

pin	The digital pin to read from. The internal pull-up resistor will be enabled when begin is called.

Definition at line 9 of file Button.cpp.

Member Function Documentation

begin()

void AH::Button::begin

(

)

Initialize (enable the internal pull-up resistor).

Definition at line 11 of file Button.cpp.

invert()

void AH::Button::invert

(

)

Invert the state of all buttons, or of this specific button (button pressed is HIGH instead of LOW).

Note

This affects all Button objects if AH_INDIVIDUAL_BUTTON_INVERT is not defined.

See also

AH_INDIVIDUAL_BUTTON_INVERT

Definition at line 13 of file Button.cpp.

update()

Button::State AH::Button::update

(

)

Read the button and return its new state.

The button is debounced, the debounce time can be set in Settings.hpp: BUTTON_DEBOUNCE_TIME.

Debounce time: ├────┤
 
Raw input:
   HIGH  ──────┐      ┌──────┐ ┌─┐      ┌─┐ ┌──────┐ ┌────────
   LOW         └──────┘      └─┘ └──────┘ └─┘      └─┘
               ├────┤ ├────┤ ├─┼─┼────┤ ├─┼─┼────┤ ├─┼────┤
 
Debounced output:
   HIGH  ──────┐      ┌──────┐          ┌──────────┐      ┌───
   LOW         └──────┘      └──────────┘          └──────┘
 
States:
   HIGH  ────────────────┐                  ┌─────────────────
   LOW                   └──────────────────┘
           RELEASED   FALLING   PRESSED   RISING

Returns

The state of the button, either Button::PRESSED, Button::RELEASED, Button::FALLING or Button::RISING.

Definition at line 19 of file Button.cpp.

getState()

Button::State AH::Button::getState

(

)

const

Get the state of the button, without updating it.

Returns the same value as the last call to update.

Returns

The state of the button, either Button::PRESSED, Button::RELEASED, Button::FALLING or Button::RISING.

Definition at line 36 of file Button.cpp.

getName()

const __FlashStringHelper * AH::Button::getName ( Button::State  state )

static

Return the name of the state as a string.

Definition at line 38 of file Button.cpp.

previousBounceTime()

unsigned long AH::Button::previousBounceTime

(

)

const

Return the time point (in milliseconds) when the button last bounced.

Definition at line 48 of file Button.cpp.

stableTime() [1/2]

unsigned long AH::Button::stableTime

(

unsigned long

now

)

const

Return the time (in milliseconds) that the button has been stable for, compared to the given time point.

Definition at line 50 of file Button.cpp.

stableTime() [2/2]

unsigned long AH::Button::stableTime

(

)

const

Return the time (in milliseconds) that the button has been stable for.

Definition at line 54 of file Button.cpp.

Member Data Documentation

pin

pin_t AH::Button::pin

private

Definition at line 112 of file Button.hpp.

prevInput

bool AH::Button::prevInput = HIGH

private

Definition at line 114 of file Button.hpp.

debouncedState

State AH::Button::debouncedState = Released

private

Definition at line 115 of file Button.hpp.

prevBounceTime

unsigned long AH::Button::prevBounceTime = 0

private

Definition at line 116 of file Button.hpp.

invertState

bool AH::Button::invertState = false

staticprivate

Definition at line 121 of file Button.hpp.

debounceTime

constexpr static unsigned long AH::Button::debounceTime = BUTTON_DEBOUNCE_TIME

staticconstexprprivate

Edit this in Settings.hpp.

See also

BUTTON_DEBOUNCE_TIME

Definition at line 126 of file Button.hpp.

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The documentation for this class was generated from the following files:

• Button.hpp
• Button.cpp