MD_UISwitch Class Reference

#include <MD_UISwitch.h>

Inheritance diagram for MD_UISwitch:

Public Types
Enumerated values and Typedefs.
enum	keyResult_t {   KEY_NULL , KEY_DOWN , KEY_UP , KEY_PRESS ,   KEY_DPRESS , KEY_LONGPRESS , KEY_RPTPRESS }

Public Member Functions
Class constructor and destructor.
	MD_UISwitch (void)
	~MD_UISwitch ()
Methods for core object control.
virtual void	begin (void)=0
virtual keyResult_t	read (void)=0
virtual uint8_t	getKey (void)
Methods for object parameters and options.
void	setPressTime (uint16_t t)
void	setDoublePressTime (uint16_t t)
void	setLongPressTime (uint16_t t)
void	setRepeatTime (uint16_t t)
void	enableDoublePress (boolean f)
void	enableLongPress (boolean f)
void	enableRepeat (boolean f)
void	enableRepeatResult (boolean f)

Protected Types
enum	state_fsm {   S_IDLE , S_PRESS , S_PRESS2A , S_PRESS2B ,   S_PRESSL , S_REPEAT , S_WAIT }
enum	state_db { S_WAIT_START , S_DEBOUNCE , S_WAIT_RELEASE }

Protected Member Functions
keyResult_t	processFSM (bool swState, bool reset=false)
bool	debounce (bool curStatus, bool reset=false)

Protected Attributes
state_fsm	_state
	the FSM current state
keyResult_t	_kPush
	storage for pushed key in FSM
uint32_t	_timeActive
	the millis() time switch was last activated
uint8_t	_enableFlags
	functions enabled/disabled
uint8_t	_RC = 0
	RC integrator value.
bool	_prevStatus
	previous 'active' status for edge detection
state_db	_RCstate
	current RC debouning state
uint16_t	_timePress
	press time in milliseconds
uint16_t	_timeDoublePress
	double press detection time in milliseconds
uint16_t	_timeLongPress
	long press time in milliseconds
uint16_t	_timeRepeat
	repeat time delay in milliseconds
uint8_t	_lastKey
	persists the last key value until a new one is detected
int16_t	_lastKeyIdx
	internal index of the last key read

Static Protected Attributes
static const uint16_t	KEY_PRESS_TIME = 150
	Default key press time in milliseconds.
static const uint16_t	KEY_DPRESS_TIME = 250
	Default double press time between presses in milliseconds.
static const uint16_t	KEY_LONGPRESS_TIME = 600
	Default long press detection time in milliseconds.
static const uint16_t	KEY_REPEAT_TIME = 300
	Default time between repeats in in milliseconds.
static const uint8_t	KEY_ACTIVE_STATE = LOW
	Default key is active low - transition high to low detection.
static const uint8_t	REPEAT_RESULT_ENABLE = 3
	Internal status bit to return KS_REPEAT instead of KS_PRESS.
static const uint8_t	DPRESS_ENABLE = 2
	Internal status bit to enable double press.
static const uint8_t	LONGPRESS_ENABLE = 1
	Internal status bit to enable long press.
static const uint8_t	REPEAT_ENABLE = 0
	Internal status bit to enable repeat key.

Detailed Description

Core object for the MD_UISwitch library

Member Enumeration Documentation

keyResult_t

enum MD_UISwitch::keyResult_t

Return values for switch status

The read() method returns one of these enumerated values as the result of the switch transition detection.

Enumerator
KEY_NULL	No key press.
KEY_DOWN	Switch is detected as active (down)
KEY_UP	Switch is detected as inactive (up)
KEY_PRESS	Simple press, or a repeated press sequence if enableRepeatResult(false) (default)
KEY_DPRESS	Double press.
KEY_LONGPRESS	Long press.
KEY_RPTPRESS	Repeated key press (only if enableRepeatResult(true))

state_db

enum MD_UISwitch::state_db

protected

Debouncing state values

States for the internal Debouncing algorithm

Enumerator
S_WAIT_START	Waiting for the debouncing to start.
S_DEBOUNCE	Currently debouncing state.
S_WAIT_RELEASE	Waiting for the next transition to be detected.

state_fsm

enum MD_UISwitch::state_fsm

protected

FSM state values

States for the internal Finite State Machine to recognized the key press

Enumerator
S_IDLE	Idle state - waiting for key transition.
S_PRESS	Detecting possible simple press.
S_PRESS2A	Detecting possible double press part A.
S_PRESS2B	Detecting possible double press part B.
S_PRESSL	Detecting possible long press.
S_REPEAT	Outputting repeat keys when timer expires.
S_WAIT	Waiting for key to be released after long press is detected.

Constructor & Destructor Documentation

MD_UISwitch()

MD_UISwitch::MD_UISwitch

(

void

)

Class Constructor.

Instantiate a new instance of the class. The main function for the core object is to initialize the internal shared variables and timers to default values.

~MD_UISwitch()

MD_UISwitch::~MD_UISwitch

(

)

Class Destructor.

Release any allocated memory and clean up anything else.

Member Function Documentation

begin()

virtual void MD_UISwitch::begin ( void  )

pure virtual

Initialize the object.

Initialize the object data. This needs to be called during setup() to initialize new data for the class that cannot be done during the object creation. This method must be replaced in the derived class.

Implemented in MD_UISwitch_Digital, MD_UISwitch_User, MD_UISwitch_Analog, MD_UISwitch_Matrix, and MD_UISwitch_4017KM.

debounce()

bool MD_UISwitch::debounce ( bool  curStatus, bool  reset = false  )

protected

Switch debounce using Edge Detection & Resistor-Capacitor Digital Filter.

A digital filter that mimics an analogue RC filter with first-order recursive low pass filter. It has good EMI filtering and quick response, with a nearly continuous output like an analogue circuit.

Parameters

curStatus	current active status for the switch.
reset	an optional identifier to reset the debounce detection.

Returns

true if the switch is 'debounced' active, false otherwise.

enableDoublePress()

void MD_UISwitch::enableDoublePress

(

boolean

f

)

Enable double press detection

Enable or disable double press detection. If disabled, two single press are detected instead of a double press. Default is to detect double press events.

Parameters

f	true to enable, false to disable.

enableLongPress()

void MD_UISwitch::enableLongPress

(

boolean

f

)

Enable long press detection

Enable or disable long press detection. If disabled, the long press notification is skipped when the event is detected and either a simple press or repeats are returned, depending on the setting of the other options. Default is to detect long press events.

Parameters

f	true to enable, false to disable.

enableRepeat()

void MD_UISwitch::enableRepeat

(

boolean

f

)

Enable repeat detection

Enable or disable repeat detection. If disabled, the long press notification is returned as soon as the long press time has expired. Default is to detect repeat events.

Parameters

f	true to enable, false to disable.

enableRepeatResult()

void MD_UISwitch::enableRepeatResult

(

boolean

f

)

Modify repeat notification

Modify the result returned from a repeat detection. If enabled, the first repeat will return a KS_PRESS and subsequent repeats will return KS_RPTPRESS. If disabled (default) the repeats will be stream of KS_PRESS values.

Parameters

f	true to enable, false to disable (default).

getKey()

virtual uint8_t MD_UISwitch::getKey ( void  )

virtual

Read the key identifier for the last switch

Return the id for the last active switch. This is useful to know which key was actually pressed when there could be more than one key (ie, a key matrix).

Returns

an identifying index for the key item, depending on implementation

processFSM()

MD_UISwitch::keyResult_t MD_UISwitch::processFSM ( bool  swState, bool  reset = false  )

protected

Process the key using FSM

Process the key read using a finite state machine to detect the current type of keypress and return one of the keypress types.

The timing for each keypress starts when the first transition of the switch from inactive to active state and is recognized by a finite state machine invoked in process() whose operation is directed by the timer and option values specified.

If the reset parameter is specified the FSM is reset to the idle state and no other processing is performed (ie, the bState parameter is ignored).

Parameters

swState	true if the switch is active, false otherwise.
reset	an optional identifier to reset the FSM.

Returns

one of the keyResult_t enumerated values.

read()

virtual keyResult_t MD_UISwitch::read ( void  )

pure virtual

Read input and return the state of the switch

Read the input key switch and invoke the process method to determine what the keystroke means. This method must be replaced in the derived class with a hardware specific method to read the key switch.

See also

processFSM() method

Returns

the keyResult_t enumerated value from processFSM()

Implemented in MD_UISwitch_Digital, MD_UISwitch_User, MD_UISwitch_Analog, MD_UISwitch_Matrix, and MD_UISwitch_4017KM.

setDoublePressTime()

void MD_UISwitch::setDoublePressTime

(

uint16_t

t

)

Set the double press detection time

Set the time between each press time in milliseconds. A double press is detected if the switch is released and depressed within this time, measured from when the first press is detected. The default value is set by the KEY_DPRESS_TIME constant.

Parameters

t	the specified time in milliseconds.

setLongPressTime()

void MD_UISwitch::setLongPressTime

(

uint16_t

t

)

Set the long press detection time

Set the time in milliseconds after which a continuous press and release is deemed a long press, measured from when the first press is detected. The default value is set by the KEY_LONGPRESS_TIME constant.

Note that the relationship between timer values should be Press Time < Long Press Time < Repeat time. No checking is done in the to enforce this relationship.

Parameters

t	the specified time in milliseconds.

setPressTime()

void MD_UISwitch::setPressTime

(

uint16_t

t

)

Set the press time

Set the switch press time in milliseconds. The default value is set by the KEY_PRESS_TIME constant.

Note that the relationship between timer values should be Press Time < Long Press Time < Repeat time. No checking is done in the to enforce this relationship.

Parameters

t	the specified time in milliseconds.

setRepeatTime()

void MD_UISwitch::setRepeatTime

(

uint16_t

t

)

Set the repeat time

Set the time in milliseconds after which a continuous press and hold is treated as a stream of repeated presses, measured from when the first press is detected.

Note that the relationship between timer values should be Press Time < Long Press Time < Repeat time. No checking is done in the to enforce this relationship.

Parameters

t	the specified time in milliseconds.

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

• src/MD_UISwitch.h
• src/MD_UISwitch.cpp