#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

byte custchar[8][8] = { // eight custom characters
  {B11111, B11111, B11111, B00000, B00000, B00000, B00000, B00000}, // 0th
  {B00000, B00000, B00000, B00000, B00000, B11111, B11111, B11111}, // 1st
  {B11111, B11111, B11111, B00000, B00000, B11111, B11111, B11111}, // 2nd
  {B00000, B00000, B00000, B00000, B00000, B01110, B01110, B01110}, // 3rd
  {B00000, B00000, B00000, B01110, B01110, B01110, B00000, B00000}, // 4th
  {B00000, B00000, B00000, B00000, B00000, B00000, B00000, B00000}, // 5th
  {B00000, B00000, B00000, B00000, B00000, B00000, B00000, B00000}, // 6th
  {B00000, B00000, B00000, B00000, B00000, B00000, B00000, B00000}  // 7th
};

byte bignums[10][2][3] = {
  {{255,   0, 255}, {255,   1, 255}}, // 0 // two rows per character
  {{  0, 255, 254}, {  1, 255,   1}}, // 1
  {{  2,   2, 255}, {255,   1,   1}}, // 2
  {{  0,   2, 255}, {  1,   1, 255}}, // 3
  {{255,   1, 255}, {254, 254, 255}}, // 4
  {{255,   2,   2}, {  1,   1, 255}}, // 5
  {{255,   2,   2}, {255,   1, 255}}, // 6
  {{  0,   0, 255}, {254, 255, 254}}, // 7
  {{255,   2, 255}, {255,   1, 255}}, // 8
  {{255,   2, 255}, {254, 254, 255}}  // 9
};

void loadchars() {
  for (int i = 0; i < 8; i++)
    lcd.createChar(i, custchar[i]);
  lcd.home();
}

void printbigchar(byte digit, byte col, byte row, byte symbol = 0) {
  if (digit > 9) return;
  for (int i = 0; i < 2; i++) {
    lcd.setCursor(col, row + i);
    for (int j = 0; j < 3; j++) {
      lcd.write(bignums[digit][i][j]);
    }
    lcd.write(254);
  }
  if (symbol == 1) {
    lcd.setCursor(col + 3, row + 1);
    lcd.write(3);
  } else if (symbol == 2) {
    lcd.setCursor(col + 3, row);
    lcd.write(4);
    lcd.setCursor(col + 3, row + 1);
    lcd.write(4);
  }

  lcd.setCursor(col + 4, row);
}

void setup() {
  lcd.init();
  lcd.backlight();
  loadchars();

  printbigchar(0, 0, 0);
  printbigchar(1, 4, 0);
  printbigchar(2, 8, 0);
  printbigchar(3, 12, 0);
  printbigchar(4, 16, 0, 1);
  printbigchar(5, 0, 2);
  printbigchar(6, 4, 2);
  printbigchar(7, 8, 2);
  printbigchar(8, 12, 2);
  printbigchar(9, 16, 2, 2);
}

void loop() {}