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

Simple library for reading a 4x4 keypad width at ability to use internal pullups

Import program
4x4KeyBoardExample - main.cpp

00001 #include "mbed.h"
00002 #include "keypad.h"
00003  
00004 Serial pc(USBTX, USBRX); 
00005 
00006  
00007 int main() {
00008                 //  c0   c1   c2   c3  r0   r1   r2   r3    
00009     Keypad keypad( PC_3,PC_2,PA_0,PA_1,PA_4,PB_0,PC_1,PC_0 );
00010        
00011     keypad.enablePullUp();
00012     char key;
00013     pc.printf("Please touch a key on the keypad\n\r");
00014     while (1) 
00015     {
00016          key = keypad.getKey();    
00017          if(key != KEY_RELEASED)
00018          {
00019              pc.printf("%c\r\n",key);
00020              wait(0.6);
00021          }
00022     }
00023 }

Import library
KeypadLib - Keypad Class Reference

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

keypad.cpp

Committer:
rlanghbv
Date:
2015-09-20
Revision:
21:fb28bc08ded4
Parent:
14:d6592dac4365

File content as of revision 21:fb28bc08ded4:

/*	 Copyright (c) 2015 Rune Langøy

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

/*
  Example is available in keypad.h

*/

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

using namespace mbed;

Keypad::Keypad(PinName col0, PinName col1, PinName col2, PinName col3,
               PinName row0,PinName row1, PinName row2, PinName row3):
    _cols(col0,col1,col2,col3) ,_rows(row0,row1,row2,row3)    {    }

void Keypad::enablePullUp()
{
    _cols.mode(PullUp);
}

bool Keypad::getKeyPressed()
{
    _rows = 0;              // Ground all keys
    if(_cols.read()==0xff)  //Chk if key is pressed
        return false;

    return true;
}

int Keypad::getKeyIndex()
{
    if (!getKeyPressed())
        return -1;

    //Scan rows and cols and return switch index
    for(int i=0; i<4; i++) {
        _rows = ~(0x01 << i);
        for(int j=0; j<4; j++)
            if (  !( (_cols.read()>> j )& 0x1 ))
                return  j + (i*4);
    }
    return -1;
}

char Keypad::getKey()
{
    int k = getKeyIndex();
    if(k != -1)
        return  keys[k];

    return 0;
}