add comment on the initial AM studio file

//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);

    };

  }

}