SoftPWM.h

00001 #ifndef SoftPWM_H
00002 #define SoftPWM_H
00003 #define POSITIVE true
00004 #define NEGATIVE false
00005 
00006 #include "mbed.h"
00007 
00008 class SoftPWM  
00009 {
00010 private:
00011     Timeout _timeout;
00012     Ticker _ticker;
00013     void end();
00014     DigitalOut pulse;
00015     bool positive;
00016     void TickerInterrapt();
00017     float width;
00018     float interval;
00019 public:
00020     SoftPWM(PinName,bool mode=true); 
00021 //    void attach_us(int);
00022     void start();
00023     void write(float);
00024     float read();
00025     void pulsewidth(float);
00026     void pulsewidth_ms(int);
00027     void pulsewidth_us(int);
00028     void period(float);
00029     void period_ms(int);
00030     void period_us(int);
00031     void stop();
00032     operator float()  { 
00033         if ( width <= 0.0 ) return 0.0;
00034         if ( width > 1.0 )  return 1.0;
00035         return width / interval;
00036     }
00037     SoftPWM& operator=(float duty)  {
00038         width = interval * duty;
00039         if ( duty <= 0.0 ) width =  0.0;
00040         if ( duty > 1.0 )  width =  interval;
00041         return *this;
00042     }
00043                 
00044 };
00045 #endif