Joystick.h

#ifndef JOYSTICK_H
#define JOYSTICK_H
#include "mbed.h"
// this value can be tuned to alter tolerance of joystick movement
#define TOL 0.1f
#define RAD2DEG 57.2957795131f

enum Direction {
  CENTRE, // 0
  u,      // 1
  r,      // 2
  d,      // 3
  l       // 4
};

struct Vector2D {
  float x;
  float y;
};
struct Polar {
  float mag;
  float angle;
};
/** Joystick Class
@author Dr Craig A. Evans, University of Leeds
@brief  Library for interfacing with analogue joystick
Example:
@code
#include "Joystick.h"
#include "mbed.h"
//                  y     x     button
Joystick joystick(PTB10,PTB11,PTC16);
int main() {
joystick.init();
while(1) {
Vector2D coord = joystick.get_coord();
printf("Coord = %f,%f\n",coord.x,coord.y);
Vector2D mapped_coord = joystick.get_mapped_coord();
printf("Mapped coord = %f,%f\n",mapped_coord.x,mapped_coord.y);
float mag = joystick.get_mag();
float angle = joystick.get_angle();
printf("Mag = %f Angle = %f\n",mag,angle);
Direction d = joystick.get_direction();
printf("Direction = %i\n",d);
if (joystick.button_pressed() ) {
printf("Button Pressed\n");
}
wait(0.5);
}
 }

* @endcode
*/
class Joystick {
public:
  //              y-pot              x-pot            button
  Joystick(PinName vertPin, PinName horizPin, PinName clickPin);
  void init();          // needs to be called at start with joystick centred
  float get_mag();      // polar
  float get_angle();    // polar
  Vector2D get_coord(); // cartesian co-ordinates x,y
  Vector2D get_mapped_coord(); // x,y mapped to circle
  Direction get_direction();   // N,NE,E,SE etc.
  Polar get_polar();           // mag and angle in struct form
  bool button_pressed(); // read button flag set in ISR when button pressed
  bool paused;
private:
  AnalogIn *vert;
  AnalogIn *horiz;
  InterruptIn *click;
  volatile int _click_flag;  // flag set in ISR
  void click_isr(); // ISR on button press
  // centred x,y values
  float _x0;
  float _y0;
};
#endif