nucleon_fw.ino

//#define MIDI_CHANNEL 1


int buttons[8][16] = {
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
};

const uint16_t keymap[8][16] = {
    {KEY_ESC, KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9, KEY_F10, KEY_F11, ' ', ' ', ' ', ' '},
    {KEY_ESC, '@', '#', '$', '%', '^', '&', '*', '(', ')', '-', '+', ' ', ' ', ' ', ' '},
    {KEY_ESC, KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9, KEY_F10, KEY_F11, ' ', ' ', ' ', ' '},
    {'`', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', KEY_BACKSPACE, KEY_PAGE_UP, KEY_INSERT},
    {KEY_TAB, 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\\', KEY_PAGE_DOWN, KEY_DELETE},
    {KEY_CAPS_LOCK, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', KEY_ENTER, ' ', KEY_UP, ' '}, 
    {KEY_LEFT_SHIFT, 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/', '/', KEY_RIGHT_SHIFT, ' ', KEY_UP, ' ',},
    {KEY_LEFT_CTRL, KEY_LEFT_GUI, KEY_LEFT_ALT, KEY_BACKSPACE, ' ', KEY_RETURN, KEY_HOME, ' ', KEY_END, KEY_RIGHT_ALT, KEY_RIGHT_GUI, KEY_RIGHT_CTRL, ' ', KEY_LEFT, KEY_DOWN, KEY_RIGHT}  
};

const int cols = 16;
const int col_pins[16] = {
  17, 16, 15, 14, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
};      

const int rows = 8;
const int row_pins[8] = {
  18, 19, 20, 21, 22, 23, 37, 38
};

void select_col_pin(int selected_pin) {
  for (int pin = 0; pin < cols; ++pin) {
    digitalWrite(col_pins[pin], LOW);
  }
  digitalWrite(col_pins[selected_pin], HIGH);
}

const int KEEB_LAYER = 0;
//const int MIDI_LAYER = 1;

//int layer = MIDI_LAYER;

void keyscan() {
  int current_button = 0;
  int prev_button = 0;
  
  for (int col = 0; col < cols; ++col) {
    select_col_pin(col);
    delay(3);
    for (int row = 0; row < rows; ++row) {
      if ( digitalRead(row_pins[row]) == HIGH) {
        current_button = 1;
      }
      else {
        current_button = 0;
      }
      prev_button = buttons[row][col];
      if (prev_button != current_button) {
          buttons[row][col] = current_button;
          if (layer == KEEB_LAYER) { 
            do_key(row, col, current_button);
          }
          //else if (layer == MIDI_LAYER) {
            //do_midi(row, col, current_button);
          //}
      }
      
    }
  }
  layer = buttons[7][12];
  //while (usbMIDI.read()) {
  //}
}

void do_key(int row, int col, int current_button) {
  /*if (row == 1 || row == 0) {
    if (current_button == 1) {
      Keyboard.press(KEY_LEFT_GUI);
      if (row == 0) {
        Keyboard.press(KEY_LEFT_SHIFT);
      }
      Keyboard.press(49 + col);
    }
    else {
      Keyboard.release(49 + col);
      if (row == 0) {
        Keyboard.release(KEY_LEFT_SHIFT);
      }
      Keyboard.release(KEY_LEFT_GUI);
    }
    return;
  }*/
  if (current_button == 1) {
    Keyboard.press(keymap[row][col]);
  }
  else {
    Keyboard.release(keymap[row][col]);
  }
}
/*
void do_midi(int row, int col, int current_button) {
  int note = 21 + (row * 16) + col;
  if (current_button == 1) { 
    usbMIDI.sendNoteOn(note, 99, MIDI_CHANNEL);
  }
  else {
    usbMIDI.sendNoteOff(note, 0, MIDI_CHANNEL);
  }
}
*/
const int led = LED_BUILTIN;

void setup() {
  // Columns are output
  for (int i = 0; i < cols; ++i) {
    pinMode(col_pins[i], OUTPUT);
  }
  // Rows are input
  for (int j = 0; j < rows; ++j) {
    pinMode(row_pins[j], INPUT_PULLDOWN);
  }
  pinMode(led, OUTPUT);
  Serial.begin(9600);
  delay(1000);
}


int switch_layer = 0;

void loop() {
  keyscan();
  digitalWrite(led, HIGH); 
  delay(20);
  digitalWrite(led, LOW);
  delay(10);
}