Revision 0:4bbd88022a6f, committed 2016-04-05

Comitter:

grantphillips

Date:

Tue Apr 05 17:37:55 2016 +0000

Commit message:

v1.00

Changed in this revision

diff -r 000000000000 -r 4bbd88022a6f Keypad.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Keypad.cpp	Tue Apr 05 17:37:55 2016 +0000
@@ -0,0 +1,59 @@
+#include "Keypad.h"
+#include "mbed.h"
+
+
+// Keypad layout:
+//                [row][col]   Col0 Col1 Col2 Col3 
+char const kpdLayout[4][4] = {{'1' ,'2' ,'3' ,'A'},  //row0
+                              {'4' ,'5' ,'6' ,'B'},  //row1
+                              {'7' ,'8' ,'9' ,'C'},  //row2
+                              {'*' ,'0' ,'#' ,'D'}}; //row3
+
+//NIBBLE LOW=0000,  HIGH= 0111 1011 1101 1110    Col  (x)
+//const char KpdInMask[4] ={0xe0,0xd0,0xb0,0x70};
+const char KpdInMask[4] ={0x0e,0x0d,0x0b,0x07};
+
+//NIBBLE HIGH=1111,  LOW= 0111 1011 1101 1110    Rows (y)
+//const char KpdOutMask[4]={0xfe,0xfd,0xfb,0xf7};  
+const char KpdOutMask[4]={0x0e,0x0d,0x0b,0x07};
+
+
+Keypad::Keypad(PinName col1, PinName col2, PinName col3, PinName col4, PinName row1, PinName row2, PinName row3, PinName row4) : _cols(col1,col2,col3,col4), _rows(row1,row2,row3,row4) {   }
+
+char Keypad::ReadKey() {
+    char KeyValue, Done=0;
+    uint16_t y, x;
+    
+    //delay_ms(ContactBounceTime);  //warning no contact bounce protection
+                                    //call read_key more than once with delay
+                                    //between if key stay constant then key is pressed
+    y = 0;
+    while((y < 4) && (!Done))
+    {
+        _cols = KpdOutMask[y];              //write mask value to the column outputs     
+        wait(0.01);  
+
+        KeyValue = _rows;                   //read mask value from the row inputs
+        
+        if(KeyValue == KpdInMask[0])
+            x = 0;
+        else if(KeyValue == KpdInMask[1])
+            x = 1;
+        else if(KeyValue == KpdInMask[2])
+            x = 2;
+        else if(KeyValue == KpdInMask[3])
+            x = 3;
+        else
+        {
+            KeyValue='\0';                  //more than one key was pressed or no key in this row.
+            x=9;          
+        }
+        if(x != 9)
+        {
+            Done = 1;                       //valid key found
+            KeyValue = kpdLayout[x][y];     //convert to a character eg. '1','2','3','#','*'
+        }
+        y++;
+    }
+    return(KeyValue);
+}
\ No newline at end of file

diff -r 000000000000 -r 4bbd88022a6f Keypad.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Keypad.h	Tue Apr 05 17:37:55 2016 +0000
@@ -0,0 +1,82 @@
+/* Keypad Library v1.0
+ * Copyright (c) 2016 Grant Phillips
+ * grant.phillips@nmmu.ac.za
+ *
+ * This is a modified version of Riaan Ehlers' library which was written for the 
+ * Microchip PIC18 series microcontrollers.
+ *
+ * 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.
+ */
+ 
+#ifndef Keypad_H
+#define Keypad_H
+ 
+#include "mbed.h"
+ 
+/** Class library for a polling-based 4x4 keypad.
+ * 
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "Keypad.h"
+ *
+ * Keypad kpad(PE_15, PE_14, PE_13, PE_12, PE_11, PE_10, PE_9, PE_8);
+ *
+ * int main() {
+ *     char key;
+ *     int released = 1;
+ *
+ *     while(1){
+ *         key = kpad.ReadKey();                   //read the current key pressed
+ *
+ *         if(key == '\0')
+ *             released = 1;                       //set the flag when all keys are released
+ *            
+ *         if((key != '\0') && (released == 1)) {  //if a key is pressed AND previous key was released
+ *             printf("%c\n", key);            
+ *             released = 0;                       //clear the flag to indicate that key is still pressed
+ *         }
+ *     }
+ * }
+ * @endcode
+ */
+ 
+class Keypad {
+  public:
+    /** Create a Keypad object.
+    * @param col1..4 DigitalOut (or BusOut) compatible pins for keypad Column data lines
+    * @param row1..4 DigitalIn (or BusIn) compatible pins for keypad Row data lines
+    */
+    Keypad(PinName col1, PinName col2, PinName col3, PinName col4, PinName row1, PinName row2, PinName row3, PinName row4);
+    
+    /** Returns the letter of the key pressed.
+    * @param 
+    *     None
+    * @return 
+    *     The character of the key pressed.  Returns '\0' if no key is pressed.
+    */
+    char ReadKey();
+    
+ 
+  private:
+    BusOut _cols;    
+    BusIn _rows;
+};
+ 
+#endif
\ No newline at end of file