CRotaryEncoder.h

00001 #ifndef CROTENC_H_INCLUDED
00002 #define CROTENC_H_INCLUDED
00003 
00004 #include "mbed.h"
00005 
00006 
00007 /* This Class handles a rotary encoder like the one from Pollin electronic (Panasonic EVEP...).
00008  * It uses two pins, one creating an interrupt on change.
00009  * Rotation direction is determined by checking the state of the other pin.
00010  *
00011  * Operating the encoder changes an internal integer value that can be read
00012  * by Get() or the operator int() functions.
00013  * A new value can be set by Set(value) or opperator=.
00014  *
00015  * Autor: Thomas Raab (Raabinator)
00016  *
00017  * Dent steady point     !     !     !
00018  *                    +-----+     +-----+
00019  * pinA (interrupt)   |     |     |     |
00020  *                  --+     +-----+     +---
00021  *                      +-----+     +-----+
00022  * pinB                 |     |     |     |
00023  *                  ----+     +-----+     +-
00024  *                           --> C.W
00025  * CW:  increases position value
00026  * CCW: decreases position value
00027  *
00028  * changelog:
00029  *
00030  * 09. Nov. 2010
00031  *     First version published.
00032  *
00033  */
00034 
00035 
00036 
00037 class CRotaryEncoder
00038 {
00039     public:
00040     CRotaryEncoder(PinName pinA, PinName pinB);
00041     ~CRotaryEncoder();
00042     
00043     int Get(void);
00044     inline operator int() { return Get(); }
00045 
00046     void Set(int value);
00047     inline CRotaryEncoder& operator= ( int  value ) { Set(value); return *this; }
00048 
00049     private:
00050     InterruptIn     *m_pinA;
00051     DigitalIn       *m_pinB;
00052     volatile int    m_position;
00053     
00054     void rise(void);
00055     void fall(void);
00056     
00057 
00058 };
00059 
00060 
00061 #endif