ButtonMatrix< nb_rows, nb_cols > Class Template Reference

A class that reads the states of a button matrix. More...

#include <AH/Hardware/ButtonMatrix.hpp>

Collaboration diagram for ButtonMatrix< nb_rows, nb_cols >:

Public Member Functions
	ButtonMatrix (const PinList< nb_rows > &rowPins, const PinList< nb_cols > &colPins)
	Construct a new ButtonMatrix object. More...
virtual	~ButtonMatrix ()=default
	Destructor. More...
void	begin ()
	Initialize (enable internal pull-up resistors on column pins). More...
void	update ()
	Scan the matrix, read all button states, and call the onButtonChanged callback. More...
bool	getPrevState (uint8_t col, uint8_t row)
	Get the state of the button in the given column and row. More...

Private Member Functions
virtual void	onButtonChanged (uint8_t row, uint8_t col, bool state)=0
	The callback function that is called whenever a button changes state. More...
void	setPrevState (uint8_t col, uint8_t row, bool state)

Static Private Member Functions
static uint8_t	positionToBits (uint8_t col, uint8_t row)
static uint8_t	bitsToIndex (uint8_t bits)
static uint8_t	bitsToBitmask (uint8_t bits)

Private Attributes
unsigned long	prevRefresh = 0
uint8_t	prevStates [(nb_cols *nb_rows+7)/8]
const PinList< nb_rows >	rowPins
const PinList< nb_cols >	colPins

Detailed Description

template<uint8_t nb_rows, uint8_t nb_cols>
class AH::ButtonMatrix< nb_rows, nb_cols >

A class that reads the states of a button matrix.

Template Parameters

nb_rows	The number of rows in the button matrix.
nb_cols	The number of columns in the button matrix.

Definition at line 23 of file ButtonMatrix.hpp.

Constructor & Destructor Documentation

ButtonMatrix()

ButtonMatrix	(	const PinList< nb_rows > &	rowPins,
		const PinList< nb_cols > &	colPins
	)

Construct a new ButtonMatrix object.

Parameters

rowPins	A list of pin numbers connected to the rows of the button matrix. ⚠ These pins will be driven LOW as outputs (Lo-Z).
colPins	A list of pin numbers connected to the columns of the button matrix. These pins will be used as inputs (Hi-Z), and the internal pull-up resistor will be enabled.

Definition at line 10 of file ButtonMatrix.ipp.

~ButtonMatrix()

virtual ~ButtonMatrix ( )

virtualdefault

Destructor.

Member Function Documentation

begin()

void begin

(

)

Initialize (enable internal pull-up resistors on column pins).

Definition at line 41 of file ButtonMatrix.ipp.

update()

void update

(

)

Scan the matrix, read all button states, and call the onButtonChanged callback.

Definition at line 17 of file ButtonMatrix.ipp.

getPrevState()

bool getPrevState	(	uint8_t	col,
		uint8_t	row
	)

Get the state of the button in the given column and row.

Note

No bounds checking is performed.

Definition at line 69 of file ButtonMatrix.ipp.

onButtonChanged()

virtual void onButtonChanged ( uint8_t  row, uint8_t  col, bool  state  )

privatepure virtual

The callback function that is called whenever a button changes state.

Parameters

row	The row of the button that changed state.
col	The column of the button that changed state.
state	The new state of the button.

positionToBits()

uint8_t positionToBits ( uint8_t  col, uint8_t  row  )

inlinestaticprivate

Definition at line 52 of file ButtonMatrix.ipp.

bitsToIndex()

uint8_t bitsToIndex ( uint8_t  bits )

inlinestaticprivate

Definition at line 59 of file ButtonMatrix.ipp.

bitsToBitmask()

uint8_t bitsToBitmask ( uint8_t  bits )

inlinestaticprivate

Definition at line 64 of file ButtonMatrix.ipp.

setPrevState()

void setPrevState ( uint8_t  col, uint8_t  row, bool  state  )

private

Definition at line 75 of file ButtonMatrix.ipp.

Member Data Documentation

prevRefresh

unsigned long prevRefresh = 0

private

Definition at line 82 of file ButtonMatrix.hpp.

prevStates

uint8_t prevStates[(nb_cols *nb_rows+7)/8]

private

Definition at line 83 of file ButtonMatrix.hpp.

rowPins

const PinList<nb_rows> rowPins

private

Definition at line 85 of file ButtonMatrix.hpp.

colPins

const PinList<nb_cols> colPins

private

Definition at line 86 of file ButtonMatrix.hpp.

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

• ButtonMatrix.hpp
• ButtonMatrix.ipp