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/*
    Copyright (c) 2010 Andy Kirkham
 
    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 AJK_DEBOUNCEIN_H
#define AJK_DEBOUNCEIN_H
 
#include "mbed.h"

/** DebounceIn adds mechanical switch debouncing to DigitialIn.
 *
 * Example:
 * @code
 * #include "mbed.h"
 * #include "DebounceIn.h"
 *
 * DebounceIn  d(p5);
 * DigitialOut led1(LED1);
 * DigitialOut led2(LED2);
 *
 * int main() {
 *     while(1) {
 *         led1 = d;
 *         led2 = d.read();
 *     }
 * }
 * @endcode
 *
 * @see set_debounce_us() To change the sampling frequency.
 * @see set_samples() To alter the number of samples.
 *
 * Users of this library may also be interested in PinDetect library:-
 * @see http://mbed.org/users/AjK/libraries/PinDetect/latest
 *
 * This example shows one input displayed by two outputs. The input
 * is debounced by the default 10ms.
 */

namespace AjK {
 
class DebounceIn {
    public:
    
    friend class DigitalIn;
    friend class Ticker;
        
        /** set_debounce_us
         *
         * Sets the debounce sample period time in microseconds, default is 25000 (25ms)
         *
         * @param uint32_t i The debounce sample period time to set.
         */        
//        void set_debounce_us(int i) { _ticker.attach_us(this, &DebounceIn::_callback, i); }
        void set_debounce_us(uint32_t i) { _debounce_us = i; _ticker->attach_us(callback(this, &DebounceIn::_callback), i); }
        
        /** get_debounce_us
         *
         * Gets the debounce sample period time in microseconds
         *
         */        
        uint32_t get_debounce_us(void) { return _debounce_us; } // // //
        
        /** set_samples
         *
         * Defines the number of samples before switching the shadow 
         * definition of the pin. 
         *
         * @param int i The number of samples.
         */        
        void set_samples(uint8_t i) { _samples = i; }

        /** get_samples
         *
         * Gets the number of samples before switching the shadow 
         * definition of the pin. 
         *
         */        
        uint8_t get_samples(void) { return _samples; }
        
        /** read
         *
         * Read the value of the debounced pin.
         */
        int8_t read(void) { return this->_shadow; }
        
#ifdef MBED_OPERATORS
        /** operator int()
         *
         * Read the value of the debounced pin.
         */
        operator int() { return read(); }
#endif  

        /** Set the pin mode.
        *
        * @see http://mbed.org/projects/libraries/api/mbed/trunk/DigitalInOut#DigitalInOut.mode
        * @param PinMode m The mode to pass on to the DigitalIn
        */
        void mode(PinMode m) { _digital_in->mode( m ); }

        /** get_edge_direction
         *
         * Gets the value of the debounced pin' edge direction (rising/falling).
         */
        int8_t get_edge_direction(void) { return _edge_direction; } // // //

        /** get_edge_direction_acted_upon
         *
         * Gets the debounced pin edge direction' usage status (used/unused)
         */
        bool get_edge_direction_acted_upon(void) { return _edge_direction_acted_upon; } // // //

        /** set_edge_direction_acted_upon
         *
         * Sets the status of the debounced pin edge direction' as used
         */
        void set_edge_direction_acted_upon(void) { _edge_direction_acted_upon = 1; } // // //

        /** Constructor
         * 
         * @param PinName pin The pin to assign as an input.
         */
        DebounceIn() { error("DebounceIn: You must supply a PinName"); }

        DebounceIn(PinName pin) { _init(pin, PullNone); };
        
        DebounceIn(PinName pin, PinMode mode) { _init(pin, mode); };

        /** DebounceIn destructor
        */    
        ~DebounceIn() {
            if ( _ticker ) { delete( _ticker ); }
            if ( _digital_in ) { delete( _digital_in ); }
        }

    protected:
    
        /** initialise class
     *
     * @param PinName p is a valid pin that supports DigitalIn
     * @param PinMode m The mode the DigitalIn should use.
     */
    void _init(PinName p, PinMode m) {
        
        _counter = 0;
        _samples = 10;
        _shadow = -1;
        _edge_direction = -1;
        _edge_direction_acted_upon = 1;
                
        _digital_in = new DigitalIn( p, m );
        _ticker = new Ticker;
        
        set_debounce_us(25000);        
    }
    
        void _callback(void) {

            if (_digital_in->read() == 1) { 
                if (_counter < _samples) _counter++; 
                if (_counter == _samples) {
                    if (_shadow == 0) { _edge_direction = 1; _edge_direction_acted_upon = 0; } // // //
                    _shadow = 1;
                    }
            }
            else { 
                if (_counter > 0) _counter--; 
                if (_counter == 0) {
                    if (_shadow == 1) { _edge_direction = 0; _edge_direction_acted_upon = 0; } // // //
                    _shadow = 0; 
                    }
            }
        }
        
        DigitalIn   *_digital_in;
        Ticker      *_ticker;
        int8_t    _shadow;
        uint32_t    _debounce_us; // // //
        int8_t    _edge_direction; // // //
        bool    _edge_direction_acted_upon; // // //
        uint8_t    _counter;
        uint8_t    _samples;
};

}; // namespace AjK ends.

using namespace AjK;
 
#endif