// For: https://forum.arduino.cc/t/millis-code-still-freezing-the-lcd-display/1069629/

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()
{
  Wire.begin();

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);      // column, row
  lcd.print( "Hello");
  delay(1000);
  lcd.clear();
  lcd.print( "LiquidCrystalI2C");
  delay(1000);
}

void loop()
{
  lcd.backlight();
  delay(1000);
  lcd.noBacklight();
  delay(1000);
  lcd.setCursor(0, 1);    // column, row
  lcd.print( millis() / 1000UL);
}