Button Box/matrix coding and wiring help

So I have a Arduino Pro Micro on the way. I've come across this video of a button box with 32 buttons total.

20 momentary push buttons / momentary toggle switches
4 rotary switches with push button.

What I'm trying to do is add 8 more momentary push buttons / momentary toggle switches taking the total to.

28 momentary push buttons / momentary toggle switches
4 rotary switches with push button.

This is how the 20 buttons and 4 rotary switches are wired in the post I was following. I need to know "If the buttons can be added how to wire them."

This is the code for the 20 buttons and 4 rotary switches with push button. I also need to know "If the other 8 buttons can be added how you would add it in the code."

//BUTTON BOX 
//USE w ProMicro

#include <Keypad.h>
#include <Joystick.h>

#define ENABLE_PULLUPS
#define NUMROTARIES 4
#define NUMBUTTONS 24
#define NUMROWS 5
#define NUMCOLS 5


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},
};

struct rotariesdef {
  byte pin1;
  byte pin2;
  int ccwchar;
  int cwchar;
  volatile unsigned char state;
};

rotariesdef rotaries[NUMROTARIES] {
  {0,1,24,25,0},
  {2,3,26,27,0},
  {4,5,28,29,0},
  {6,7,30,31,0},
};

#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

byte rowPins[NUMROWS] = {21,20,19,18,15}; 
byte colPins[NUMCOLS] = {14,16,10,9,8}; 

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();

}

void CheckAllButtons(void) {
      if (buttbx.getKeys())
    {
       for (int i=0; i<LIST_MAX; i++)   
        {
           if ( buttbx.key[i].stateChanged )   
            {
            switch (buttbx.key[i].kstate) {  
                    case PRESSED:
                    case HOLD:
                              Joystick.setButton(buttbx.key[i].kchar, 1);
                              break;
                    case RELEASED:
                    case IDLE:
                              Joystick.setButton(buttbx.key[i].kchar, 0);
                              break;
            }
           }   
         }
     }
}


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);
}

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);
    };
  }
}

Thanks in advance for any help and hopefully I posted this all per forum guidelines.

Did you try what that video did?

I don't see any pins available to add other rows (or columns) of buttons.

It can be done, yes, but by changing the hardware and, obviously, the code.

The video was for 32 buttons total. I have not tried anything as of yet as the board won't be here until tomorrow. Thanks for asking!

This is what I was afraid of but no biggie I did order two pro micro's when I ordered just for that reason lol... Thanks for the reply. I'll just have them programmed the same for a total of 40 momentary switches and 8 rotaries...

Thanks for replying!!!

Is this the video? It uses a promicro

Yes I ordered two of them. I was trying to see if you could add 8 more momentary buttons to this. My thoughts have been confirmed hence the reason I bought two Arduino pro micro's. I believe I'm now going to use one for buttons and one for rotaries. I may just program them to do 32 total buttons each. I built a sim racing cockpit with a dash and I'm going to put the buttons in the dash instead of a box.

If you would have bought an Arduino Micro, I'm quite sure you would have been able to do what you want without additional hardware.

Pro Micros are nice if you need a small board or a 3.3V board and if you can live with the pin limitation.

To extend the capabilities of the Pro Micro, you can use (I2C or SPI) port expanders or shift registers. They all only use two or three pins regardless of the number of devices that you connect.

Thanks! I wish I had thought about getting a Micro instead of the ProMicro. Hindsight is 20/20 lol. Oh well I'm sure I'll plenty more little projects to arise.

A post was split to a new topic: Add extra buttons to button box project