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

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

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

Committer:
rlanghbv
Date:
Sat Sep 19 07:51:21 2015 +0000
Revision:
1:fa689a04c361
Parent:
0:1fa357ea3fcc
Child:
14:d6592dac4365
First commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rlanghbv 1:fa689a04c361 1 /* Copyright (c) 2015 Rune Langøy
DimiterK 0:1fa357ea3fcc 2
DimiterK 0:1fa357ea3fcc 3 Permission is hereby granted, free of charge, to any person obtaining a copy
DimiterK 0:1fa357ea3fcc 4 of this software and associated documentation files (the "Software"), to deal
DimiterK 0:1fa357ea3fcc 5 in the Software without restriction, including without limitation the rights
DimiterK 0:1fa357ea3fcc 6 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
DimiterK 0:1fa357ea3fcc 7 copies of the Software, and to permit persons to whom the Software is
DimiterK 0:1fa357ea3fcc 8 furnished to do so, subject to the following conditions:
DimiterK 0:1fa357ea3fcc 9
DimiterK 0:1fa357ea3fcc 10 The above copyright notice and this permission notice shall be included in
DimiterK 0:1fa357ea3fcc 11 all copies or substantial portions of the Software.
DimiterK 0:1fa357ea3fcc 12
DimiterK 0:1fa357ea3fcc 13 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
DimiterK 0:1fa357ea3fcc 14 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
DimiterK 0:1fa357ea3fcc 15 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
DimiterK 0:1fa357ea3fcc 16 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
DimiterK 0:1fa357ea3fcc 17 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
DimiterK 0:1fa357ea3fcc 18 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
DimiterK 0:1fa357ea3fcc 19 THE SOFTWARE.
DimiterK 0:1fa357ea3fcc 20 */
DimiterK 0:1fa357ea3fcc 21
rlanghbv 1:fa689a04c361 22 /*
rlanghbv 1:fa689a04c361 23 Example is available in keypad.h
DimiterK 0:1fa357ea3fcc 24
rlanghbv 1:fa689a04c361 25 */
DimiterK 0:1fa357ea3fcc 26
DimiterK 0:1fa357ea3fcc 27 #include "mbed.h"
DimiterK 0:1fa357ea3fcc 28 #include "keypad.h"
DimiterK 0:1fa357ea3fcc 29
DimiterK 0:1fa357ea3fcc 30 using namespace mbed;
DimiterK 0:1fa357ea3fcc 31
rlanghbv 1:fa689a04c361 32 Keypad::Keypad(PinName col0, PinName col1, PinName col2, PinName col3,
rlanghbv 1:fa689a04c361 33 PinName row0,PinName row1, PinName row2, PinName row3):
rlanghbv 1:fa689a04c361 34 _cols(col0,col1,col2,col3) ,_rows(row0,row1,row2,row3) { }
rlanghbv 1:fa689a04c361 35
rlanghbv 1:fa689a04c361 36 void Keypad::enablePullUp()
rlanghbv 1:fa689a04c361 37 {
rlanghbv 1:fa689a04c361 38 _cols.mode(PullUp);
rlanghbv 1:fa689a04c361 39 }
DimiterK 0:1fa357ea3fcc 40
rlanghbv 1:fa689a04c361 41 bool Keypad::getKeyPressed()
rlanghbv 1:fa689a04c361 42 {
rlanghbv 1:fa689a04c361 43 _rows = 0; // Ground all keys
rlanghbv 1:fa689a04c361 44 if(_cols.read()==0xff) //Chk if key is pressed
rlanghbv 1:fa689a04c361 45 return false;
rlanghbv 1:fa689a04c361 46
rlanghbv 1:fa689a04c361 47 return true;
rlanghbv 1:fa689a04c361 48 }
rlanghbv 1:fa689a04c361 49
rlanghbv 1:fa689a04c361 50 int Keypad::getKeyIndex()
rlanghbv 1:fa689a04c361 51 {
rlanghbv 1:fa689a04c361 52 if (!getKeyPressed())
rlanghbv 1:fa689a04c361 53 return -1;
rlanghbv 1:fa689a04c361 54
rlanghbv 1:fa689a04c361 55 //Scan rows and cols and return switch index
rlanghbv 1:fa689a04c361 56 for(int i=0; i<4; i++)
rlanghbv 1:fa689a04c361 57 { _rows = ~(0x01 << i);
rlanghbv 1:fa689a04c361 58 for(int j=0; j<4;j++)
rlanghbv 1:fa689a04c361 59 if ( !( (_cols.read()>> j )& 0x1 ))
rlanghbv 1:fa689a04c361 60 return j + (i*4);
DimiterK 0:1fa357ea3fcc 61 }
DimiterK 0:1fa357ea3fcc 62 return -1;
DimiterK 0:1fa357ea3fcc 63 }
DimiterK 0:1fa357ea3fcc 64
rlanghbv 1:fa689a04c361 65 char Keypad::getKey()
rlanghbv 1:fa689a04c361 66 {
rlanghbv 1:fa689a04c361 67 int k = getKeyIndex();
rlanghbv 1:fa689a04c361 68 if(k != -1)
rlanghbv 1:fa689a04c361 69 return keys[k];
rlanghbv 1:fa689a04c361 70
rlanghbv 1:fa689a04c361 71 return 0;
DimiterK 0:1fa357ea3fcc 72 }