scan a 4x4 keypad by polling it continuously.
Dependents: Keyboard_LCD tarea6_teclado keypad
keypad.cpp
00001 /* Copyright (c) 2010 Dimiter Kentri 00002 00003 Permission is hereby granted, free of charge, to any person obtaining a copy 00004 of this software and associated documentation files (the "Software"), to deal 00005 in the Software without restriction, including without limitation the rights 00006 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 00007 copies of the Software, and to permit persons to whom the Software is 00008 furnished to do so, subject to the following conditions: 00009 00010 The above copyright notice and this permission notice shall be included in 00011 all copies or substantial portions of the Software. 00012 00013 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 00014 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00015 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 00016 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 00017 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 00018 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 00019 THE SOFTWARE. 00020 */ 00021 00022 /*Simple example 00023 00024 #include "mbed.h" 00025 #include "keypad.h" 00026 00027 Serial pc(USBTX, USBRX); 00028 Keypad telepad(p13,p14,p15,p16,p17,p18,p19,p20); 00029 00030 int main(void){ 00031 char key; 00032 pc.printf("Enter codes\n\r"); 00033 while(1){ 00034 key = telepad.getKey(); 00035 if(key != KEY_RELEASED){ 00036 pc.printf("%c\n",key); 00037 wait(0.6); 00038 } 00039 } 00040 } */ 00041 00042 #include "mbed.h" 00043 #include "keypad.h" 00044 00045 using namespace mbed; 00046 00047 Keypad::Keypad(PinName col1, PinName col2, PinName col3, PinName col4, PinName row1,PinName row2, PinName row3, PinName row4): _col1(col1), 00048 _col2(col2),_col3(col3),_col4(col4),_rows(row1,row2,row3,row4) { 00049 00050 } 00051 00052 int Keypad::getKeyIndex(){ 00053 for(int k=0; k<4; k++) { 00054 _rows = 0; 00055 } 00056 for(int i=0; i<4; i++) { 00057 _rows = 1 << i; 00058 for(int j=0; j<4;j++){ 00059 if (_col1) 00060 return 1+(i*4); 00061 else if (_col2) 00062 return 2+(i*4); 00063 else if (_col3) 00064 return 3+(i*4); 00065 else if (_col4) 00066 return 4+(i*4); 00067 } 00068 } 00069 return -1; 00070 } 00071 00072 char Keypad::getKey(){ 00073 int k = getKeyIndex(); 00074 if(k != -1) 00075 return keys[k-1]; 00076 else 00077 return 0; 00078 }
Generated on Wed Jul 13 2022 16:20:39 by 1.7.2