Istvan Cserny / Hotboards_keypad

Sense keypresses from a 4x4 keypad A derivative ot he Hotboard_keypad library

Dependents:   26_Hotboards_MultiKey 26_Hotboards_EventKeypad

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Keypad Class Reference
Public Member Functions

Keypad Class Reference

Hotboards_keypad class. More...

#include <Hotboards_keypad.h>

Inherits Key.

Public Member Functions

 Keypad (char *userKeymap, DigitalInOut *row, DigitalInOut *col, uint8_t numRows, uint8_t numCols)
 Allows custom keymap, pin configuration, and keypad sizes.
char getKey (void)
 Returns a single key only.
bool getKeys (void)
 Populate the key list (check public key array).
KeyState getState (void)
 Get the state of the first key on the list of active keys.
void begin (char *userKeymap)
 Let the user define a keymap - assume the same row/column count as defined in constructor.
bool isPressed (char keyChar)
 Return a true if the selected key is pressed.
void setDebounceTime (uint)
 Set a new debounce time (1ms is the minimum value)
void setHoldTime (uint)
 Set a new time to considered a key is in hold state.
void addEventListener (void(*listener)(char))
 Set a callback function to be called everytime an key change its status.
int findInList (char keyChar)
 Search by character for a key in the list of active keys.
int findInList (int keyCode)
 Search by code for a key in the list of active keys.
char waitForKey (void)
 lock everything while waiting for a keypress.
bool keyStateChanged (void)
 Return stateChanged element of the first key from the active list.
uint8_t numKeys (void)
 The number of keys on the key list, key[LIST_MAX].

Detailed Description

Hotboards_keypad class.

Used to control general purpose leds

Example: 

 #include "mbed.h"
 #include "Hotboards_keypad.h"

 char keys[ 4 ][ 4 ] =
 {
    {'1','2','3','A'},
    {'4','5','6','B'},
    {'7','8','9','C'},
    {'*','0','#','D'}
 };
 DigitalInOut rowPins[ 4 ] = {PC_0, PC_1, PC_2, PC_3}; 
 DigitalInOut colPins[ 4 ] = {PB_2, PB_1, PB_15, PB_14};

 Keypad kpd( makeKeymap( keys ), rowPins, colPins, 4, 4 );

 int main( void ) 
 {
    while(1){
       char key = keypad.getKey( );
       if( key ){
           // do something with key
       }
    }
 }

Definition at line 94 of file Hotboards_keypad.h.

Constructor & Destructor Documentation

Keypad ( char *  userKeymap,
DigitalInOut *  row,
DigitalInOut *  col,
uint8_t  numRows,
uint8_t  numCols 
)

Allows custom keymap, pin configuration, and keypad sizes.

Parameters:
userKeymappointer to bidimentional array with key definitions
rowpointer to array with pins conected to rows
colpointer to array with pins conected to columns
numRowsnumber of rows in use
numColsnumber of columns in use

Example: 

   char keys[ 4 ][ 4 ] =
   {
     {'1','2','3','A'},
     {'4','5','6','B'},
     {'7','8','9','C'},
     {'*','0','#','D'}
   };
   DigitalInOut rowPins[ 4 ] = {PC_0, PC_1, PC_2, PC_3}; 
   DigitalInOut colPins[ 4 ] = {PB_2, PB_1, PB_15, PB_14};
   Keypad kpd( makeKeymap( keys ), rowPins, colPins, 4, 4 );

Definition at line 43 of file Hotboards_keypad.cpp.

Member Function Documentation

void addEventListener ( void(*)(char)  listener )

Set a callback function to be called everytime an key change its status.

Parameters:
listenerfunction to be called

Example: 

   kpd.addEventListener( keypadEvent );

Definition at line 255 of file Hotboards_keypad.cpp.

void begin ( char *  userKeymap )

Let the user define a keymap - assume the same row/column count as defined in constructor.

Parameters:
userKeymappointer to user keymap

Example: 

   // lets assume user wnats to change the keymap
   kpd.begin( makeKeymap( NewKeys )),

Definition at line 61 of file Hotboards_keypad.cpp.

int findInList ( char  keyChar )

Search by character for a key in the list of active keys.

Returns:
Returns -1 if not found or the index into the list of active keys.

Example: 

   // kpd.getKeys function needs to be called first
   int index = findInList( '7' );
   if( kpd.key[ index ].stateChanged ){
     // the key change, so do something =)
   }

Definition at line 202 of file Hotboards_keypad.cpp.

int findInList ( int  keyCode )

Search by code for a key in the list of active keys.

Returns:
Returns -1 if not found or the index into the list of active keys.

Example: 

   // kpd.getKeys function needs to be called first
   int index = findInList( 10 );
   if( kpd.key[ index ].stateChanged ){
     // the key change, so do something =)
   }

Definition at line 213 of file Hotboards_keypad.cpp.

char getKey ( void   )

Returns a single key only.

Retained for backwards compatibility.

Returns:
key pressed (user defined key)

Example: 

   char key = keypad.getKey( );
   if( key ){
     // do something with key
   }

Definition at line 66 of file Hotboards_keypad.cpp.

bool getKeys ( void   )

Populate the key list (check public key array).

Returns:
true if user pressed any key(s)

Example: 

 if( kpd.getKeys( ) ){
   // you need to poll the array kpd.key[]
   for( int i=0 ; i<LIST_MAX ; i++ ){
     if( kpd.key[ i ].stateChanged ){ 
       chat = kpd.key[ i ].kchar;
     }
 }

Definition at line 78 of file Hotboards_keypad.cpp.

KeyState getState ( void   )

Get the state of the first key on the list of active keys.

Returns:
key[0].kstate

Example: 

   if(kpd.getState() == PRESSED ){
     // do something
   }

Definition at line 230 of file Hotboards_keypad.cpp.

bool isPressed ( char  keyChar )

Return a true if the selected key is pressed.

Is neccesary to call getKeys function first

Returns:
key pressed (user defined key)

Example: 

  if( kpd.getKeys( ) ){
    if( kpd.isPressed( '2' ) ){
      // key '2' have been press
    }
  }

Definition at line 190 of file Hotboards_keypad.cpp.

bool keyStateChanged ( void   )

Return stateChanged element of the first key from the active list.

Returns:
key[0].stateChanged

Example: 

   if( kpd.keyStateChanged() ){
     // do something
   }

Definition at line 236 of file Hotboards_keypad.cpp.

uint8_t numKeys ( void   )

The number of keys on the key list, key[LIST_MAX].

Returns:
number of keys

Example: 

   int keyNum = numKeys();

Definition at line 242 of file Hotboards_keypad.cpp.

void setDebounceTime ( uint  debounce )

Set a new debounce time (1ms is the minimum value)

Parameters:
debouncetime in milliseconds

Example: 

  // change default 10ms debounce time to 20ms
  kpd.setDebounceTime( 20 );

Definition at line 247 of file Hotboards_keypad.cpp.

void setHoldTime ( uint  hold )

Set a new time to considered a key is in hold state.

Parameters:
holdhold time in milliseconds

Example: 

  // change default 500ms hold time to 250ms
  kpd.setHoldTime( 250 );

Definition at line 251 of file Hotboards_keypad.cpp.

char waitForKey ( void   )

lock everything while waiting for a keypress.

Returns:
key pressed

Example: 

   char key = kpd.waitForKey();

Definition at line 223 of file Hotboards_keypad.cpp.

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