Class library for a polling-based 4x4 keypad.
Dependents: LCD kbdlcdkl25z control_onoff control_onoff ... more
Diff: Keypad.h
- Revision:
- 0:4bbd88022a6f
--- /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