arduino-joystick/Joystick.h

#ifndef _JOYSTICK_H_
#define _JOYSTICK_H_

#include <Arduino.h>
#include <Bounce2.h>
#include <list>

using std::list;

// If you're using the arduino-big-joystick firmware, these numbers can't be
// changed. If you're writing your own Report Descriptor, tune these to match by
// defining them *before* you include Joystick.h.
#ifndef JOYSTICK_NUM_AXES
#define JOYSTICK_NUM_AXES 8
#endif
#ifndef JOYSTICK_NUM_BUTTONS
#define JOYSTICK_NUM_BUTTONS 40
#endif
#define JOYSTICK_NUM_BYTES (JOYSTICK_NUM_BUTTONS+7)/8

enum ButtonType {
  BUTTON_PASSTHRU = 0x1, // always use the (debounced) absolute state of the input
  BUTTON_PULSED = 0x2, // on button press, send an on signal followed immediately by an off signal.
  BUTTON_PULSED_DOUBLE_ACTION = 0x4, // Send a button press twice - once for press and once for release.
  BUTTON_PULSED_DOUBLE_ACTION_SPLIT = 0x8, // Send two separate button presses - one button on press, another on release.
  BUTTON_LATCHED_MOMENTARY = 0x10
};

struct JoyReport {
  int16_t axis[JOYSTICK_NUM_AXES];
  uint8_t button[JOYSTICK_NUM_BYTES];
};

struct Button {
  ButtonType type;
  Bounce bouncer;
  uint8_t index0;
  uint8_t index1; // only used by BUTTON_PULSED_DOUBLE_ACTION_SPLIT
  bool pressed = false; // only used by BUTTON_LATCHED_MOMENTARY
  bool inverted = false; // if true, send button press on release and vice versa.
};

bool operator ==(JoyReport a, JoyReport b);
bool operator !=(JoyReport a, JoyReport b);

class Joystick {
  public:
    Joystick(bool debug=false);
    void Init();
    void Update();
    
    void AddButton(uint8_t pin, ButtonType type, bool pullup=true);
    void AddAxis(uint8_t pin); // Axes don't actually work yet!
    
    // Public access to these functions is deprecated and they may become private in a future
    // version. Prefer the above API instead.
    void SetAxis(uint8_t axis, int16_t value);
    void PressButton(uint8_t button);
    void ReleaseButton(uint8_t button);
    void ReleaseAllButtons();
    void Write();

  private:
    void _ReleasePulsedButtons();
    void _UpdateButton(uint8_t index);
    void _UpdateAxis(uint8_t index);
    
    Button _buttons[JOYSTICK_NUM_BUTTONS];
    uint8_t _num_buttons;
    uint8_t _last_button_index; // a single physical button can have multiple logical buttons. _last_button_index tracks the number of logical / virtual buttons we have defined.
    bool _have_pulsed_button;

    uint8_t _axes[JOYSTICK_NUM_AXES];
    uint8_t _num_axes;
    
    JoyReport _joyReport;
    bool _debug;
};

// Internal use only.
#define _BUTTON_PULSED_TYPES (BUTTON_PULSED | BUTTON_PULSED_DOUBLE_ACTION | BUTTON_PULSED_DOUBLE_ACTION_SPLIT)

#endif