Rune Langoy / KeypadLib

4x4 Keypad easy to use library that pollis the interface width pullups

Dependents:   4x4KeyBoardExample xoxokey 4x4KeyBoardExample ProgettoCassaforte ... more

Fork of keypad by Dimiter K

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Keypad Class Reference
Public Member Functions | Protected Member Functions

Keypad Class Reference

An simple polling-based interface to read a 4x4 keypad. More...

#include <keypad.h>

Public Member Functions

 Keypad (PinName col0, PinName col1, PinName col2, PinName col3, PinName row0, PinName row1, PinName row2, PinName row3)
 Create a 4x4 (col, row) or 4x4 keypad interface
.
char getKey ()
 Returns the letter of the pressed key
.
bool getKeyPressed ()
 Detects if any key was pressed.
void enablePullUp ()
 Enables internal PullUp resistors on the coloums pins.

Protected Member Functions

int getKeyIndex ()
 return the index value representating the pressed key

Detailed Description

An simple polling-based interface to read a 4x4 keypad.

The function getKey() reads the index of the pressed key and returns the letter of the pressed key

This work is a derivative of the works done by: Dimiter Kentri in 2010 https://developer.mbed.org/users/DimiterK/code/keypad/ and Yoong Hor Meng in 2012 https://developer.mbed.org/users/yoonghm/code/keypad/

Example: 

 #include "mbed.h"
 #include "keypad.h"

 Serial pc(USBTX, USBRX);
 Keypad keypad(D3,D4,D5,D6,D7,D8,D9,D10);
 // Keypad keypad( PC_3,PC_2,PA_0,PA_1,PA_4,PB_0,PC_1,PC_0 ); // Tested on  Nucleo303RE card

 int main(void)
 {
  keypad.enablePullUp();
  char key;
  pc.printf("Please touch a key on the keypad\r\n");
  while(1)
  {
    key = keypad.getKey();
    if(key != KEY_RELEASED)
    {
       pc.printf("%c\r\n",key);
       wait(0.2);
     }
  }
 }

Definition at line 82 of file keypad.h.

Constructor & Destructor Documentation

Keypad ( PinName  col0,
PinName  col1,
PinName  col2,
PinName  col3,
PinName  row0,
PinName  row1,
PinName  row2,
PinName  row3 
)

Create a 4x4 (col, row) or 4x4 keypad interface
. 

          | Col0 | Col1 | Col2 | Col3   


   -------+------+------+------+-----   


   Row 0  |   x  |   x  |   x  |  x     


   Row 1  |   x  |   x  |   x  |  x     


   Row 2  |   x  |   x  |   x  |  x     


   Row 3  |   x  |   x  |   x  |  x
Parameters:
col<0..3>Row data lines
row<0..3>Column data lines

Definition at line 32 of file keypad.cpp.

Member Function Documentation

void enablePullUp (  )

Enables internal PullUp resistors on the coloums pins.

Returns:
void

Definition at line 36 of file keypad.cpp.

char getKey (  )

Returns the letter of the pressed key
.

Returns:
char
The pressed character
'\0' or NO_KEY if no keys was pressed

Definition at line 65 of file keypad.cpp.

int getKeyIndex (  ) [protected]

return the index value representating the pressed key

Returns:
int
The index representing the pushed key used in table keys
-1 if no key was pressed

Definition at line 50 of file keypad.cpp.

bool getKeyPressed (  )

Detects if any key was pressed.

Returns:
bool
Return values:
truea key is pressed
falseno keys was not pressed

Definition at line 41 of file keypad.cpp.

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