#include <LCD_I2C.h>
LCD_I2C lcd(0x27,20,4);

// siehe: https://forum.arduino.cc/t/wie-bekommt-man-solch-grosse-zahlen-hin/986148/3


byte largeLetterPart0[8] = {
  B00000,
  B00000,
  B00000,
  B00000,
  B00001,
  B00111,
  B01111,
  B11111,
};

byte largeLetterPart1[8] = {
  B00000,
  B00000,
  B00000,
  B00000,
  B11111,
  B11111,
  B11111,
  B11111,
};

byte largeLetterPart2[8] = {
  B00000,
  B00000,
  B00000,
  B00000,
  B10000,
  B11100,
  B11110,
  B11111,
};

byte largeLetterPart3[8] = {
  B11111,
  B01111,
  B00111,
  B00001,
  B00000,
  B00000,
  B00000,
  B00000,
};


byte largeLetterPart4[8] = {
  B11111,
  B11111,
  B11111,
  B11111,
  B00000,
  B00000,
  B00000,
  B00000,
};

byte largeLetterPart5[8] = {
  B11111,
  B11110,
  B11100,
  B10000,
  B00000,
  B00000,
  B00000,
  B00000,
};

byte largeLetterPart6[8] = {
  B11111,
  B11111,
  B11111,
  B11111,
  B11111,
  B01111,
  B00111,
  B00001,
};

byte largeLetterPart7[8] = {
  B11111,
  B11111,
  B11111,
  B11111,
  B11111,
  B11110,
  B11100,
  B10000,
};


byte digitData[4][30] = {
  // 0           1               2            3          4              5             6             7              8              9
  {0,   1,   2, ' ',   0,   1,   0,   1,   2, 0, 1,   2,   0, ' ',   1, 1,   1,   1,   0,   1,   2,   1,   1,   1,   0,   1,   2,   0,   1,   2},
  {255, 0, 255, ' ',   5, 255,   4,   0,   7, 4, 0,   7, 255, ' ', 255, 6,   1,   2, 255,   1,   2, ' ',   0,   7,   6,   1,   7,   6,   1, 255},
  {255, 5, 255, ' ', ' ', 255, 255,   5, ' ', 1, 3, 255,   4,   4, 255, 1, ' ', 255, 255, ' ', 255, 255,   5, ' ', 255, ' ', 255, ' ', ' ', 255},
  {3,   4,   5, ' ', ' ',   4,    4,   4,  4, 3, 4,   5, ' ', ' ',   4, 3,   4,   5,   3,   4,   5,   4, ' ', ' ',   3,   4,   5,   3,   4,   5},
};

void writeLargeDigit(byte column, byte digit) {
  byte index = (digit % 10) * 3;
  for (byte row = 0; row < 4; row++) {
    lcd.setCursor(column, row);
    for (byte i = 0; i < 3; i++) {
      lcd.write(digitData[row][index + i]);
    }
  }
};


void setup() {
  lcd.begin();                      // initialize the lcd 
  lcd.backlight();
  lcd.createChar(0, largeLetterPart0);
  lcd.createChar(1, largeLetterPart1);
  lcd.createChar(2, largeLetterPart2);
  lcd.createChar(3, largeLetterPart3);
  lcd.createChar(4, largeLetterPart4);
  lcd.createChar(5, largeLetterPart5);
  lcd.createChar(6, largeLetterPart6);
  lcd.createChar(7, largeLetterPart7);

  lcd.print("Hallo");
  
}

void loop() {
  
  delay(2000);
  lcd.clear();
  writeLargeDigit(0, 0);
  writeLargeDigit(4, 1);
  writeLargeDigit(8, 2);
  writeLargeDigit(12, 3);
  writeLargeDigit(16, 4);

  delay(2000);
  lcd.clear();
  writeLargeDigit(0, 5); 
  writeLargeDigit(4, 6);
  writeLargeDigit(8, 7);
  writeLargeDigit(12, 8);
  writeLargeDigit(16, 9);
}