File content as of revision 4:3aca44118b7a:

 /* PinDetectMod
 *  Copyright (c) 2015 Giuliano Dianda
 *  Released under the MIT License: http://mbed.org/license/mit
 *
 *  Rework of: PinDetect by Andy Kirkham
 */
 
/*
    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 PIN_DETECT_MOD_H
#define PIN_DETECT_MOD_H

#ifndef MBED_H
#include "mbed.h"
#endif

#ifndef PINDETECT_PINSTATES
#define PINDETECT_PINSTATES

// pin state bitmask
#define S_IDLE          0
#define S_RINGING       ((uint32_t)1<<0)
#define S_ASSERTED      ((uint32_t)1<<1)
#define S_HELD          ((uint32_t)1<<2)

#endif

/** PinDetectMod is a rework of PinDetect, .
 *
 * Unlike the original PinDetect which samples pin at specified rate, here is all about interrupts and timers,
 * because for some application the continuous sampling of a mostly idle pin is an overhead.
 * Pin state is evaluated in sequence deasserted->ringing->asserted->(->held_asserted)->ringing->deasserted
 * callback function can be attached to these state changes:
 * deasserted->asserted (e.g. as soon as button is pressed)
 * asserted->deasserted (e.g quick button pulse)
 * asserted->held_asserted (e.g. as soon as the button is evaluated to be held)
 * held_asserted->deasserted (e.g. long button pulse)
 * 
 * Only callbacks that have been attached will be called by the library.
 *
 * Example:
 * @code
 * #include "mbed.h"
 * #include "PinDetectMod.h"
 *
 * DigitalOut led1( LED1 );
 * PinDetect pin(p30, PullUp, 0);
 *
 * void keyPressed( void ) {
 *     backligh_on();
 * }
 *
 * void keyQuickPulsed( void ) {
 *     increasevalue();
 * }
 *
 * void keyPressedHeld( void ) {
 *     beep();
 * }
 *
 * void keyLongPulsed( void ) {
 *     setup_menu();
 * }
 *
 * int main() {
 *
 *     pin.attach_asserted( &keyPressed );
 *     pin.attach_deasserted( &keyQuickPulsed );
 *     pin.attach_asserted_held( &keyPressedHeld );
 *     pin.attach_deasserted_held( &keyLongPulsed );
 *
 *
 *     while( 1 ) {
 *         led1 = !led1;
 *         wait( 0.2 );
 *     }
 * }
 * @endcode
 *
 */
class PinDetect {


    
public:

    /** PinDetect constructor
     *
     * @see http://mbed.org/handbook/DigitalIn
     * @param p PinName is a valid pin that supports DigitalIn
     * @param m PinMode (PullUp, PullDown, PullNone....)
     * @param assertvalue pin state to be considered as asserted (0 or 1)
     * @param debounce_us debounce time in microseconds, default 5000
     * @param held_us time in microseconds for the state to be considered held_asserted, default 2000000
     */    
    PinDetect(PinName p, PinMode m, int assertvalue, unsigned int debounce_us=5000, unsigned int held_us=2000000): interr(p), _assertvalue(assertvalue)
    {
        debouncetime=debounce_us;
        heldtime=held_us;
        bouncein=0;
        bounceout=0;
        disable();
        if (_assertvalue) {   // pulse up
            interr.rise(this, &PinDetect::startpulse); // first rise then fall
            interr.fall(this, &PinDetect::endpulse);

        } else {   // pulse down
            interr.fall(this, &PinDetect::startpulse); // first fall then rise
            interr.rise(this, &PinDetect::endpulse);
        }
        interr.mode(m);
        statereset(); // pinstate=S_IDLE;
        trig=false;
        enable();
    }
    
    /** PinDetect destructor
     */    
    ~PinDetect() {
        interr.disable_irq();
        timeoutbounce.detach();
        timeoutheld.detach();
    }
    /** Disable
     */ 
    void disable()
    {
        interr.disable_irq();
        statereset();
    }
    /** Enable
     */ 
    void enable()
    {
        interr.enable_irq();
        statereset();
    }
    
    /** Set debounce time
     *
     * @param dbtime microseconds
     */    
    void setDebounceTime(unsigned int dbtime) { debouncetime = dbtime; }
    
    /** Set time until held assumed.
     *
     * @param htime microseconds
     */    
    void setHeldTime(unsigned int htime) { heldtime = htime; }

    
    /** Attach a callback function 
     *
     * @code
     *
     * DigitalOut led1( LED1 );
     * PinDetect pin(p30, PullUp, 0);
     *
     * void myCallback( void ) {
     *   led1 = 1;
     * };
     * 
     * main() {
     *     pin.attach_asserted( &myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is asserted.
     * @param function A C function pointer
     */
    void attach_asserted(void (*function)(void)) {
        callbackAsserted.attach( function );
    }
    
    /** Attach a callback object/method 
     *
     * @code
     *
     * class Bar {
     *   public:
     *     void myCallback( void ) { led1 = 1; }
     * };
     *
     * DigitalOut led1( LED1 );
     * PinDetect pin(p30, PullUp, 0);
     * Bar bar;
     *
     * main() {
     *     pin.attach_asserted( &bar, &Bar::myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is asserted.
     * @param object An object that conatins the callback method.
     * @param method The method within the object to call.
     */
    template<typename T>
    void attach_asserted(T *object, void (T::*member)(void)) {
        callbackAsserted.attach( object, member );        
    }
    
    /** Attach a callback function 
     *
     * @code
     *
     * DigitalOut led1( LED1 );
     * PinDetect pin(p30, PullUp, 0);
     *
     * void myCallback( void ) {
     *   led1 = 0;
     * };
     *
     * main() {
     *     pin.attach_deasserted( &myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is deasserted (short pulse).
     * @param function A C function pointer
     */
    void attach_deasserted(void (*function)(void)) {
        callbackDeasserted.attach( function );
    }
    
    /** Attach a callback object/method
     *
     * @code
     *
     * class Bar {
     *   public:
     *     void myCallback( void ) { led1 = 0; }
     * };
     *
     * DigitalOut led1( LED1 );
     * PinDetect pin(p30, PullUp, 0);
     * Bar bar;
     * 
     * main() {
     *     pin.attach_deasserted( &bar, &Bar::myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is deasserted (short pulse).
     * @param object An object that conatins the callback method.
     * @param method The method within the object to call.
     */
    template<typename T>
    void attach_deasserted(T *object, void (T::*member)(void)) {
        callbackDeasserted.attach( object, member );        
    }
    
    /** Attach a callback function 
     *
     * @code
     *
     * DigitalOut led2( LED2 );
     * PinDetect pin(p30, PullUp, 0);
     *
     * void myCallback( void ) {
     *   led2 = 1;
     * };
     *
     * main() {
     *     pin.attach_asserted_held( &myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is asserted and held.
     * @param function A C function pointer
     */
    void attach_asserted_held(void (*function)(void)) {
        callbackAssertedHeld.attach( function );
    }
    
    /** Attach a callback object/method
     *
     * @code
     *
     * class Bar {
     *   public:
     *     void myCallback( void ) { led2 = 0; }
     * };
     *
     * DigitalOut led2( LED2 );
     * PinDetect pin(p30, PullUp, 0);
     * Bar bar;
     * 
     * main() {
     *     pin.attach_asserted_held( &bar, &Bar::myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is asserted and held.
     * @param object An object that conatins the callback method.
     * @param method The method within the object to call.
     */
    template<typename T>
    void attach_asserted_held(T *object, void (T::*member)(void)) {
        callbackAssertedHeld.attach( object, member );        
    }
    
    /** Attach a callback function 
     *
     * @code
     *
     * DigitalOut led3( LED3 );
     * PinDetect pin(p30, PullUp, 0);
     *
     * void myCallback( void ) {
     *   led3 = 1;
     * };
     *
     * main() {
     *     pin.attach_deasserted_held( &myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is deasserted after being held.
     * @param function A C function pointer
     */
    void attach_deasserted_held(void (*function)(void)) {
        callbackDeassertedHeld.attach( function );
    }
    
    /** Attach a callback object/method
     *
     * @code
     *
     * class Bar {
     *   public:
     *     void myCallback( void ) { led3 = 0; }
     * };
     *
     * DigitalOut led3( LED3 );
     * PinDetect pin(p30, PullUp, 0);
     * Bar bar;
     * 
     * main() {
     *     pin.attach_deasserted_held( &bar, &Bar::myCallback );
     * }
     *
     * @endcode
     *
     * Call this function when a pin is deasserted after being held.
     * @param object An object that conatins the callback method.
     * @param method The method within the object to call.
     */
    template<typename T>
    void attach_deasserted_held(T *object, void (T::*member)(void)) {
        callbackDeassertedHeld.attach( object, member );        
    }
    
    /** operator int()
     *
     * Read the value of the pin being sampled.
     */
    operator int() { return interr.read(); }
    
    /** Get the current pin state
     *
     * @return pinstate bitmask S_HELD|S_ASSERTED|S_RINGING, 0=S_IDLE
     */
    unsigned int state()
    {
        return pinstate;
    }
    
    /** Reset pinstate to S_IDLE and reset debounce/held timers 
     */
    void statereset()
    {
        pinstate=S_IDLE;
        timeoutheld.detach();
        timeoutbounce.detach();
        pinstate=S_IDLE;
    }
    /** Get the total bounces for deasserted->asserted
     *
     * @return bounces so far
     */
    unsigned int getbouncein()
    {
        return bouncein;
    }
    /** Get the total bounces for asserted->deasserted
     *
     * @return bounces so far
     */
    unsigned int getbounceout()
    {
        return bounceout;
    }

protected:

    void startpulse()
    {
        pinstate|=S_RINGING;
        if((pinstate&S_ASSERTED)==0) timeoutbounce.attach_us(this, &PinDetect::onasserted, debouncetime);
        // else if state is asserted and we are here, it means we are debouncing transition to deasserted, timeout is already attached to ondeasserted()
        trig=true;  // ISR completed
    }

    void endpulse()
    {
        if(!trig) return; // first check if the previous startpulse ISR completed
        pinstate|=S_RINGING;
        
        if((pinstate&S_ASSERTED)!=0) // if was asserted or held asserted, debounce transition to deasserted
        {
            timeoutheld.detach();
            timeoutbounce.attach_us(this, &PinDetect::ondeasserted, debouncetime);
        }
        trig=false;
    }
    
    void onasserted()
    {
        if(interr.read()!=_assertvalue)
        {
            bouncein++;
            return; // was a bounce
        }
        pinstate|=S_ASSERTED; // set asserted
        pinstate&= ~(S_RINGING|S_HELD); // clear ringing and held
        timeoutheld.attach_us(this, &PinDetect::onheld, heldtime);
        callbackAsserted.call(); // call function for pin state change (deasserted -> asserted)
    }
    
    void onheld()
    {
        if((pinstate&S_RINGING)!=0 || (pinstate&S_ASSERTED)==0 || (interr.read()!=_assertvalue)) return; // to be valid, needs ringing=false asserted=true pinread=assertvalue
        pinstate|=S_HELD; // set held
        callbackAssertedHeld.call(); // call function for pin state change (asserted -> held asserted)
    }
    
    void ondeasserted()
    {
        if((pinstate&(S_ASSERTED))==0) return; // pinstate was reset externally
        if(interr.read()==_assertvalue)
        {
            bounceout++;
            return; // was a bounce
        }
        if((pinstate&S_HELD)==0) callbackDeasserted.call(); // call function for pin state change (asserted -> deasserted)(quick pulse)
        else callbackDeassertedHeld.call(); // call function for pin state change (held asserted -> deasserted)(long pulse)
        pinstate=S_IDLE;
    }
    
private:
    InterruptIn interr;
    Timeout      timeoutbounce;
    Timeout      timeoutheld;
    unsigned int debouncetime;
    unsigned int heldtime;
    int         _assertvalue;
    FunctionPointer callbackAsserted;
    FunctionPointer callbackDeasserted;
    FunctionPointer callbackAssertedHeld;
    FunctionPointer callbackDeassertedHeld;
    volatile unsigned int pinstate;
    volatile unsigned int bouncein;
    volatile unsigned int bounceout;
    
    bool trig;
    
};


#endif