Scrittura su LCD 20x4 QC2004A

Basta modificare lcd.begin(16, 2) in lcd.begin (20, 4)

       #include <LiquidCrystal.h>
      
      LiquidCrystal lcd(8, 9, 10, 11, 12, 13);
      //  pin LCD       RS E  D4   D5 D6  D7
     
      void setup() 
      
          { lcd.begin(20, 4); }
      
      void loop() {
       
             lcd.setCursor(0, 0);
             lcd.print("Prima riga");
             lcd.setCursor(0, 1);
             lcd.print("Seconda riga");
             lcd.setCursor(0, 2);
             lcd.print("Terza riga");
             lcd.setCursor(0, 3);
             lcd.print("Quarta riga ");
         }