mini (Pi)QWERTY USB keyboard

Keyboard have 4 layouts switchable with FN button.

• lowercase letters
• uppercase letters
• CTRL + lowercase letter
• CAPS LOCK

of course tweaking is unlimited, you can make own layouts

#include <Keypad.h>
#include "Keyboard.h"
const byte ROWS = 7; //four rows
const byte COLS = 8; //four columns
byte rowPins[ROWS] = {15, 18, 16, 19, 28, 31, 30}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {3, 4, 5, 6, 7, 8, 9, 14}; //connect to the column pinouts of the keypad
//define the cymbols on the buttons of the keypads
char directKeys[ROWS][COLS] = {
  {'`', '1', '2', '3', '4', '5', '6', 1},
  {KEY_ESC, 'q', 'w', 'e', 'r', 't', 'y', ';'},
  {'[', 'a', 's', 'd', 'f', 'g', 'h', 39}, //39 is '
  {']', 'z', 'x', 'c', 'v', 'b', 'n', '-'},
  {'7', '8', '9', '0', KEY_DOWN_ARROW, KEY_RIGHT_ARROW, KEY_LEFT_ARROW, KEY_UP_ARROW},
  {'u', 'i', 'o', 'p', '.', '/', ' ', '='},
  {'j', 'k', 'l', KEY_BACKSPACE, 'm', 92, KEY_RETURN, ','}
};
char shiftKeys[ROWS][COLS] = {
  {'~', '!', '@', '#', '$', '%', '^', 1},
  {KEY_TAB, 'Q', 'W', 'E', 'R', 'T', 'Y', ';'},
  {'{', 'A', 'S', 'D', 'F', 'G', 'H', 34}, //34 is "
  {'}', 'Z', 'X', 'C', 'V', 'B', 'N', '_'},
  {'&', '*', '(', ')', KEY_PAGE_DOWN, KEY_END, KEY_HOME, KEY_PAGE_UP},
  {'U', 'I', 'O', 'P', '>', '?', ' ', '+'},
  {'J', 'K', 'L', KEY_DELETE, 'M', 92, KEY_RETURN, ','}
};
char fnKeys[ROWS][COLS] = {
  {'`', KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, 1},
  {KEY_ESC, 'q', 'w', 'e', 'r', 't', 'y', ';'},
  {'[', 'a', 's', 'd', 'f', 'g', 'h', 39}, //39 is '
  {']', 'z', 'x', 'c', 'v', 'b', 'n', '-'},
  {KEY_F7, KEY_F8, KEY_F9, KEY_F10, KEY_DOWN_ARROW, KEY_RIGHT_ARROW, KEY_LEFT_ARROW, KEY_UP_ARROW},
  {'u', 'i', 'o', 'p', '.', '/', ' ', '='},
  {'j', 'k', 'l', KEY_BACKSPACE, 'm', 92, KEY_RETURN, ','}
};
char capsKeys[ROWS][COLS] = {
  {'`', '1', '2', '3', '4', '5', '6', 1},
  {KEY_ESC, 'Q', 'W', 'E', 'R', 'T', 'Y', ';'},
  {'[', 'A', 'S', 'D', 'F', 'G', 'H', 39}, //39 is '
  {']', 'Z', 'X', 'C', 'V', 'B', 'N', '-'},
  {'7', '8', '9', '0', KEY_DOWN_ARROW, KEY_RIGHT_ARROW, KEY_LEFT_ARROW, KEY_UP_ARROW},
  {'U', 'I', 'O', 'P', '.', '/', ' ', '='},
  {'J', 'K', 'L', KEY_BACKSPACE, 'M', 92, KEY_INSERT, ','}
};

// Create 3 new key layouts
Keypad directLayout( makeKeymap(directKeys), rowPins, colPins, sizeof(rowPins), sizeof(colPins) );
Keypad shiftLayout( makeKeymap(shiftKeys), rowPins, colPins, sizeof(rowPins), sizeof(colPins) );
Keypad fnLayout( makeKeymap(fnKeys), rowPins, colPins, sizeof(rowPins), sizeof(colPins) );
Keypad capsLayout( makeKeymap(capsKeys), rowPins, colPins, sizeof(rowPins), sizeof(colPins) );
byte Layout = 0;
char Key = 0;
#define ledaA 27
#define ledFn 17
void setup() {
  Keyboard.begin();
  pinMode(ledaA, OUTPUT);
  pinMode(ledFn, OUTPUT);
  digitalWrite(ledaA, LOW);
  digitalWrite(ledFn, LOW);
  directLayout.begin( makeKeymap(directKeys) );
  shiftLayout.begin( makeKeymap(shiftKeys) );
  fnLayout.begin( makeKeymap(fnKeys) );
  capsLayout.begin( makeKeymap(capsKeys) );
}

void loop() {
  switch (Layout) {
    case 0:
      digitalWrite(ledaA, LOW);
      digitalWrite(ledFn, LOW);
      Key = directLayout.getKey();
      break;

    case 1:
      digitalWrite(ledaA, HIGH);
      digitalWrite(ledFn, LOW);
      Key = shiftLayout.getKey();
      if (Key >= 2) {
        Layout = 0;
      }
      break;

    case 2:
      digitalWrite(ledaA, LOW);
      digitalWrite(ledFn, HIGH);
      Key = fnLayout.getKey();
      if (Key >= 2) {
        Layout = 0; //
      }
      if (Key == KEY_RETURN)
      {
        Keyboard.press(KEY_LEFT_SHIFT);
      }
      if ((Key >= 'a') && (Key <= 'z'))
      {
        Keyboard.press(KEY_LEFT_CTRL);
      }
      break;

    case 3:
      digitalWrite(ledaA, HIGH);
      digitalWrite(ledFn, HIGH);
      Key = capsLayout.getKey();
      break;
    default:
      Layout = 0;
      break;
  }
  if (Key == 1)
  {
    Layout++;
    Key = 0;
    delay(300); // 

  if (Key) {
    //  Keyboard.press(ctrlKey);
    Keyboard.press(Key);
    delay(100);
    Keyboard.releaseAll();
  }
}

Half of firmware working, I need write Shift / FN support. , is incredibly simple.

I regret that I used such a powerful processor.

Sketch uses 11808 bytes (4%) of program storage space. Maximum is 253952 bytes.

#include <Keypad.h>
#include "Keyboard.h"
const byte ROWS = 7; //four rows
const byte COLS = 8; //four columns
char Keys[ROWS][COLS] = {
  {'`','1','2','3','4','5','6','X'},
  {KEY_ESC,'q','w','e','r','t','y',';'},
  {'[','a','s','d','f','g','h','*'},
  {']','z','x','c','v','b','n','-'},
  {'7','8','9','0',KEY_DOWN_ARROW,KEY_RIGHT_ARROW,KEY_LEFT_ARROW,KEY_UP_ARROW},
  {'u','i','o','p','.','/',' ','='},
  {'j','k','l',KEY_BACKSPACE,'m',92,KEY_RETURN,','}
};
byte rowPins[ROWS] = {15, 18, 16, 19,28,31,30}; 
byte colPins[COLS] = {3, 4, 5, 6,7,8,9,14}; 
Keypad customKeypad = Keypad( makeKeymap(Keys), rowPins, colPins, ROWS, COLS); 
void setup(){
  Keyboard.begin();
}
void loop(){
  char customKey = customKeypad.getKey();
  if (customKey){
  Keyboard.press(customKey);
  delay(100);
  Keyboard.releaseAll();
  }
}

You can adjust button height with spacers between boards. Of course you can use any button sizes an colors,
this button height is hard explainable (etc. my distributor have only this height with 1N switch force) but on real device is very interesting, of course in any height nobody can say that keyboard is comfortable. but 1N force version is very soft and easy to press.

One bad is, every color have different switching force.

Please understand this is only technology preview no new fashion line and all keyboard is only for short writing.

I am just ordered boards ... blue soldermask, in future all colors :D

better layout more buttons and always in good dimensions :)

7.4874 sq in (3.9150in x 1.9125in) / 4830.57 sq/mm (99.44mm x 48.58mm)

I started new project based on this keyboard

https://hackaday.io/project/158479-pocket-computer-terminal

- 2 layers bottom with buttons and top layer with nice silk (exactly like old Russians guys)
(effective use 10x10cm cm PCB order 1. half layer buttons an logic + 2. half layer front panel)

- buttons only and silkscreen .... more hardcore look

Russian engineers it solve years ago when make clone of ZX spectrum