scan a 3x4 keypad with softaware pulldown resistors by polling it continuously.

Fork of keypad by Dimiter K

Revision:
1:b8305e120e11
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/keypad3x4.cpp	Fri May 08 06:50:54 2015 +0000
@@ -0,0 +1,65 @@
+
+
+//Dimiter Kentri update
+
+
+/*	 Copyright (c) 2010 Dimiter Kentri
+
+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.
+*/
+
+#include "mbed.h"
+#include "keypad3x4.h"
+
+using namespace mbed;
+
+Keypad::Keypad(PinName col1,PinName col2,PinName col3,PinName row1,PinName row2,PinName row3,PinName row4):_col1(col1),_col2(col2),_col3(col3),_rows(row1,row2,row3,row4)    
+{    
+	_col1.mode(PullUp);
+	_col2.mode(PullUp);
+	_col3.mode(PullUp);      
+}     
+
+int Keypad::getKeyIndex()
+{
+    _rows = 0;   
+    for(int i=0; i<4; i++) 
+    {
+        _rows = 1 << i;     
+	    for(int j=0; j<4;j++)
+	    {         
+        	if (_col1)
+          		return 1+(i*3);
+    		else if (_col2)
+                return 2+(i*3);
+            else if (_col3)
+                return 3+(i*3);            
+        }
+    }    
+    return 11;
+}          
+
+char Keypad::getKey()
+{
+	int k = getKeyIndex();    
+	if(k != 11)
+    	return  keys[k-1];
+ 	else 
+ 		return 0;
+}