Joystick.h

00001 #ifndef JOYSTICK_H
00002 #define JOYSTICK_H
00003 
00004 #include "mbed.h"
00005 
00006 // this value can be tuned to alter tolerance of joystick movement
00007 #define TOL 0.1f
00008 #define RAD2DEG 57.2957795131f
00009 
00010 enum Direction {
00011     CENTRE,  // 0
00012     N,       // 1
00013     NE,      // 2
00014     E,       // 3
00015     SE,      // 4
00016     S,       // 5
00017     SW,      // 6
00018     W,       // 7
00019     NW      // 8
00020 };
00021 
00022 struct Vector2D {
00023   float x;
00024   float y;  
00025 };
00026 
00027 struct Polar {
00028     float mag;
00029     float angle;
00030 };
00031 
00032 /** Joystick Class
00033 @author Dr Craig A. Evans, University of Leeds
00034 @brief  Library for interfacing with analogue joystick
00035 
00036 Example:
00037 
00038 @code
00039 
00040 #include "mbed.h"
00041 #include "Joystick.h"
00042 
00043 //                  y     x     button
00044 Joystick joystick(PTB10,PTB11,PTC16);
00045 
00046 int main() {
00047     
00048     joystick.init();
00049     
00050     while(1) {
00051     
00052         Vector2D coord = joystick.get_coord();
00053         printf("Coord = %f,%f\n",coord.x,coord.y);
00054         
00055         Vector2D mapped_coord = joystick.get_mapped_coord(); 
00056         printf("Mapped coord = %f,%f\n",mapped_coord.x,mapped_coord.y); 
00057         
00058         float mag = joystick.get_mag();
00059         float angle = joystick.get_angle();
00060         printf("Mag = %f Angle = %f\n",mag,angle);
00061         
00062         Direction d = joystick.get_direction();
00063         printf("Direction = %i\n",d);
00064         
00065         if (joystick.button_pressed() ) {
00066             printf("Button Pressed\n");  
00067         }
00068           
00069         wait(0.5);
00070     }
00071     
00072     
00073 }
00074 
00075 * @endcode
00076 */
00077 class Joystick
00078 {
00079 public:
00080     
00081     //              y-pot              x-pot            button
00082     Joystick(PinName vertPin,PinName horizPin,PinName clickPin);
00083     
00084     void init();  // needs to be called at start with joystick centred
00085     float get_mag();              // polar
00086     float get_angle();            // polar
00087     Vector2D get_coord();         // cartesian co-ordinates x,y
00088     Vector2D get_mapped_coord();  // x,y mapped to circle
00089     Direction get_direction();    // N,NE,E,SE etc.
00090     Polar get_polar();            // mag and angle in struct form
00091     bool button_pressed();        // read button flag set in ISR when button pressed
00092     
00093 private:
00094 
00095     AnalogIn *vert;
00096     AnalogIn *horiz;
00097     InterruptIn *click;
00098     
00099     int _click_flag;    // flag set in ISR
00100     void click_isr();   // ISR on button press
00101        
00102     // centred x,y values    
00103     float _x0;
00104     float _y0;
00105     
00106 };
00107 
00108 #endif