#include <LiquidCrystal.h>
const int rs = 4;
const int en = 2;
const int d4 = 21;
const int d5 = 19;
const int d6 = 18;
const int d7 = 5;
const int lcdColumns = 16;
const int lcdRows = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() 
{
  lcd.begin(lcdColumns, lcdRows);
  lcd.clear();
  Serial.begin(9600);
  Serial.println("Enter your custom message:");
  Serial.write("*");
}

void loop() {
  lcd.setCursor(0, 0);
  lcd.print("Type msg@SerialMonitor");
  if (Serial.available()) 
  {
    String customMessage = Serial.readStringUntil('\n');
    lcd.setCursor(0, 1);
    lcd.print(customMessage);
   
  }
   lcd.clear();
}