Button Class Reference

#include <AH/Hardware/Button.hpp>

Detailed Description

A class for reading and debouncing buttons and switches.

Examples

2.Button.ino, CountPressedButtons.ino, and Toggle-LEDs.ino.

Definition at line 15 of file Button.hpp.

Collaboration diagram for Button:

Classes
struct	InternalState

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...
void	invert ()
	Invert the input state of this 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 FlashString_t	getName (State state)
	Return the name of the state as a string. More...
static void	setDebounceTime (unsigned long debounceTime=BUTTON_DEBOUNCE_TIME)
	Set the debounce time for all Buttons. More...
static unsigned long	getDebounceTime ()
	Get the debounce time. More...

Private Attributes
pin_t	pin
struct Button::InternalState	state

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

Member Enumeration Documentation

State

enum State

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

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

Definition at line 45 of file Button.hpp.

Constructor & Destructor Documentation

Button() [1/2]

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 24 of file Button.hpp.

Button() [2/2]

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 5 of file Button.cpp.

Member Function Documentation

begin()

void begin

(

)

Initialize (enable the internal pull-up resistor).

Examples

CountPressedButtons.ino, and Toggle-LEDs.ino.

Definition at line 7 of file Button.cpp.

invert()

void invert

(

)

Invert the input state of this button (button pressed is HIGH instead of LOW).

Definition at line 9 of file Button.cpp.

update()

Button::State 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 11 of file Button.cpp.

getState()

Button::State 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 32 of file Button.cpp.

getName()

FlashString_t getName ( Button::State  state )

static

Return the name of the state as a string.

Definition at line 36 of file Button.cpp.

previousBounceTime()

unsigned long previousBounceTime

(

)

const

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

Definition at line 46 of file Button.cpp.

stableTime() [1/2]

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.

Definition at line 50 of file Button.cpp.

stableTime() [2/2]

unsigned long stableTime

(

)

const

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

Definition at line 54 of file Button.cpp.

setDebounceTime()

void setDebounceTime ( unsigned long  debounceTime = BUTTON_DEBOUNCE_TIME )

static

Set the debounce time for all Buttons.

Note

This function affects all Button objects.

Parameters

debounceTime

The new debounce time in milliseconds.

Definition at line 56 of file Button.cpp.

getDebounceTime()

unsigned long getDebounceTime ( )

static

Get the debounce time.

Returns

The debounce time in milliseconds.

See also

setDebounceTime

Definition at line 60 of file Button.cpp.

Member Data Documentation

pin

pin_t pin

private

Definition at line 122 of file Button.hpp.

state

struct Button::InternalState state

private

debounceTime

unsigned long debounceTime = BUTTON_DEBOUNCE_TIME

staticprivate

Edit this in Settings.hpp.

See also

BUTTON_DEBOUNCE_TIME

Definition at line 137 of file Button.hpp.

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

• Button.hpp
• Button.cpp