DebouncedInterrupt.h

00001  
00002 #ifndef DEBOUNCED_INTERRUPT_H
00003 #define DEBOUNCED_INTERRUPT_H
00004 
00005 #include <stdint.h>
00006 #include "mbed.h"
00007 #include "FunctionPointer.h"
00008 
00009 /**
00010 typedef enum {
00011     IRQ_NONE,
00012     IRQ_RISE,
00013     IRQ_FALL
00014 } gpio_irq_event;
00015 **/
00016 
00017 /** A replacement for InterruptIn that debounces the interrupt
00018  *
00019  * Example:
00020  * @code
00021  *
00022  * #include "DebouncedInterrupt.h"
00023  *
00024  * DebouncedInterrupt up_button(p15);
00025  * 
00026  * void onUp()
00027  * {
00028  *    // Do Something
00029  * }
00030  * 
00031  * int main()
00032  * {
00033  *     up_button.attach(&onUp,IRQ_FALL, 100);
00034  *     while(1) {
00035  *         ...
00036  *     }
00037  * }
00038  * @endcode
00039  */
00040 class DebouncedInterrupt {
00041 private:
00042     unsigned int _debounce_us;
00043     InterruptIn *_in;
00044     DigitalIn *_din;
00045     gpio_irq_event _trigger;
00046     
00047     // Diagnostics
00048     volatile unsigned int _bounce_count;
00049     volatile unsigned int _last_bounce_count;
00050     
00051     void _onInterrupt(void);
00052     void _callback(void);
00053 public:
00054     DebouncedInterrupt(PinName pin);
00055     ~DebouncedInterrupt();
00056     
00057     // Start monitoring the interupt and attach a callback
00058     void attach(void (*fptr)(void), const gpio_irq_event trigger, const uint32_t& debounce_ms=10);
00059     
00060     template<typename T>
00061     void attach(T* tptr, void (T::*mptr)(void), const gpio_irq_event trigger, const uint32_t& debounce_ms=10) {
00062         _fAttach.attach(tptr, mptr);
00063         _last_bounce_count = _bounce_count = 0;
00064         _debounce_us = 1000*debounce_ms;
00065         _trigger = trigger;
00066         
00067         switch(trigger)
00068         {
00069             case IRQ_RISE:
00070                 _in->rise(tptr, &DebouncedInterrupt::_onInterrupt);
00071                 break;
00072             case IRQ_FALL:
00073                 _in->fall(tptr, &DebouncedInterrupt::_onInterrupt);
00074                 break;
00075             case IRQ_NONE:
00076                 reset(); // Unexpected. Clear callbacks.
00077                 break;
00078         }
00079     }
00080    
00081     // Stop monitoring the interrupt
00082     void reset();
00083     
00084     
00085     /*
00086     * Get number of bounces 
00087     * @return: bounce count
00088     */
00089     unsigned int get_bounce();
00090 protected:
00091 //    https://github.com/mbedmicro/mbed/blob/master/libraries/mbed/api/FunctionPointer.h
00092     FunctionPointer _fAttach;
00093 };
00094 #endif