//BUTTON BOX 
//USE w ProMicro
//Tested in WIN10 + Assetto Corsa
//AMSTUDIO
//20.8.17

// code taken from https://github.com/AM-STUDIO/32-FUNCTION-BUTTON-BOX/blob/master/ARDUINO_BUTTON_BOXV2.ino


//include 2 libraries to manage grid layout and une gamepad features
#include <Keypad.h>
#include <Joystick.h>

//define values
#define ENABLE_PULLUPS
#define NUMROTARIES 4
#define NUMBUTTONS 24

//grid size 5 x 5 
#define NUMROWS 5
#define NUMCOLS 5

//this is the matching between the grid and the button number that will be triggered
//for instance , if I physically press the button plug in the grid at the column 1 , row 2
// the program will send the gamepad signal that the button 5 have been pressed
byte buttons[NUMROWS][NUMCOLS] = {
  {0,1,2,3,4},
  {5,6,7,8,9},
  {10,11,12,13,14},
  {15,16,17,18,19},
  {20,21,22,23},
};


//define a custom structure to manage easily the rotary encoder
struct rotariesdef {
  byte pin1; // the Arduino pin connected to the A side of the rotary encoder
  byte pin2; // the Arduino pin connected to the B side of the rotary encoder
  int ccwchar; //ccw => counter clockwise this is the character/ the button of the gamepad that will be pressed when user turn the rotary counter clockwise
  int cwchar;//cw =>  clockwise this is the character/ the button of the gamepad that will be pressed when user turn the rotary clockwise
  volatile unsigned char state; => state to know if the user turn clockwise or counter clockwise
};

//as define earlier, there is 4 rotaries encoders 
//so it defines the structure rotariesdef for each rotary 
// for instance:
// the first rotry is connected to pin 0 and 1 of the arduino
// if the user turn counter clockwise , the button 24 will be pressed
// if the user turn clockwise , the button 25 will be pressed
rotariesdef rotaries[NUMROTARIES] {
  {0,1,24,25,0}, 
  {2,3,26,27,0},
  {4,5,28,29,0},
  {6,7,30,31,0},
};

//define some value to be used to know if the rotary is turned and what direction (ccw or cw)
// and depending if there is HALF_STEP or not it will use one set of data or the other
#define DIR_CCW 0x10
#define DIR_CW 0x20
#define R_START 0x0

#ifdef HALF_STEP
#define R_CCW_BEGIN 0x1
#define R_CW_BEGIN 0x2
#define R_START_M 0x3
#define R_CW_BEGIN_M 0x4
#define R_CCW_BEGIN_M 0x5
const unsigned char ttable[6][4] = {
  // R_START (00)
  {R_START_M,            R_CW_BEGIN,     R_CCW_BEGIN,  R_START},
  // R_CCW_BEGIN
  {R_START_M | DIR_CCW, R_START,        R_CCW_BEGIN,  R_START},
  // R_CW_BEGIN
  {R_START_M | DIR_CW,  R_CW_BEGIN,     R_START,      R_START},
  // R_START_M (11)
  {R_START_M,            R_CCW_BEGIN_M,  R_CW_BEGIN_M, R_START},
  // R_CW_BEGIN_M
  {R_START_M,            R_START_M,      R_CW_BEGIN_M, R_START | DIR_CW},
  // R_CCW_BEGIN_M
  {R_START_M,            R_CCW_BEGIN_M,  R_START_M,    R_START | DIR_CCW},
};
#else
#define R_CW_FINAL 0x1
#define R_CW_BEGIN 0x2
#define R_CW_NEXT 0x3
#define R_CCW_BEGIN 0x4
#define R_CCW_FINAL 0x5
#define R_CCW_NEXT 0x6

const unsigned char ttable[7][4] = {
  // R_START
  {R_START,    R_CW_BEGIN,  R_CCW_BEGIN, R_START},
  // R_CW_FINAL
  {R_CW_NEXT,  R_START,     R_CW_FINAL,  R_START | DIR_CW},
  // R_CW_BEGIN
  {R_CW_NEXT,  R_CW_BEGIN,  R_START,     R_START},
  // R_CW_NEXT
  {R_CW_NEXT,  R_CW_BEGIN,  R_CW_FINAL,  R_START},
  // R_CCW_BEGIN
  {R_CCW_NEXT, R_START,     R_CCW_BEGIN, R_START},
  // R_CCW_FINAL
  {R_CCW_NEXT, R_CCW_FINAL, R_START,     R_START | DIR_CCW},
  // R_CCW_NEXT
  {R_CCW_NEXT, R_CCW_FINAL, R_CCW_BEGIN, R_START},
};
#endif


//define the arduino pin used for the grid 
byte rowPins[NUMROWS] = {21,20,19,18,15}; 
byte colPins[NUMCOLS] = {14,16,10,9,8}; 

//manage easily the keypad based on the define grid
Keypad buttbx = Keypad( makeKeymap(buttons), rowPins, colPins, NUMROWS, NUMCOLS); 


Joystick_ Joystick(JOYSTICK_DEFAULT_REPORT_ID, 
  JOYSTICK_TYPE_JOYSTICK, 32, 0,
  false, false, false, false, false, false,
  false, false, false, false, false);

void setup() {
  Joystick.begin();
  rotary_init();}

void loop() { 

  CheckAllEncoders();

  CheckAllButtons();

}

//equivalent of the ButtonCheck(int inputNb, int gamepadButtonNb) of my version
// but it is managed the same way for every button 
void CheckAllButtons(void) {
  
    if (buttbx.getKeys())
    {
       for (int i=0; i<LIST_MAX; i++)   
        {
           if ( buttbx.key[i].stateChanged )   
            {
            switch (buttbx.key[i].kstate) {
                    //depending on the case, button is pressed or release  
                    case PRESSED:
                    case HOLD:
                              Joystick.setButton(buttbx.key[i].kchar, 1);
                              break;
                    case RELEASED:
                    case IDLE:
                              Joystick.setButton(buttbx.key[i].kchar, 0);
                              break;
            }
           }   
         }
     }
}

//for all the rotary encoder,
// it defines default value
void rotary_init() {
  for (int i=0;i<NUMROTARIES;i++) {
    pinMode(rotaries[i].pin1, INPUT);
    pinMode(rotaries[i].pin2, INPUT);
    #ifdef ENABLE_PULLUPS
      digitalWrite(rotaries[i].pin1, HIGH);
      digitalWrite(rotaries[i].pin2, HIGH);
    #endif
  }
}


unsigned char rotary_process(int _i) {
   unsigned char pinstate = (digitalRead(rotaries[_i].pin2) << 1) | digitalRead(rotaries[_i].pin1);
  rotaries[_i].state = ttable[rotaries[_i].state & 0xf][pinstate];
  return (rotaries[_i].state & 0x30);
}


// for each rotary, check the state with the  rotary_process(int _i) function
// and depending on the case it set the clockwise or counter clockwise button 
void CheckAllEncoders(void) {
  for (int i=0;i<NUMROTARIES;i++) {
    unsigned char result = rotary_process(i);
    if (result == DIR_CCW) {
      Joystick.setButton(rotaries[i].ccwchar, 1); delay(50); Joystick.setButton(rotaries[i].ccwchar, 0);
    };
    if (result == DIR_CW) {
      Joystick.setButton(rotaries[i].cwchar, 1); delay(50); Joystick.setButton(rotaries[i].cwchar, 0);
    };
  }
}