Code for connecting 2 LCD display to Arduino board with just 7 digital I/O pins. Project explanation - https://youtu.be/DFX627wrCvE

Connecting_multiple_16*2_LCD_Display_to_Arduino.in_

// Connecting multiple 16*2 LCD Display to Arduino
// by Varad Kulkarni <http://www.microcontrollershub.com>
// Created on 18 June 2018

#include <LiquidCrystal.h>
LiquidCrystal lcd1(12, 11, 5, 4, 3, 2);
LiquidCrystal lcd2(12, 10, 5, 4, 3, 2);

// Change following variables as per your need
char * LargeText = "    Connecting 2 - 16*2 LCD with Arduino by microcontrollershub.       ";

int iLineNumber = 1;                                                                   // Line number to show your string (Either 0 or 1)

int iCursor = 0;

void setup() 
{
  lcd1.begin(16, 2);                                                                   // Initialise both LCD.
  lcd2.begin(16, 2);
  lcd1.clear();
  lcd2.clear();
}

void loop() 
{
  UpdateLCDDisplay();                                                                  // Update text on LCD Display.
  delay(160);                                                                          // Change this value to change speed of scrolling text.
  lcd1.clear();
  lcd2.clear();
  delay(60);
}

void UpdateLCDDisplay()
{
  int iLenOfLargeText = strlen(LargeText);                                            // Calculate length of string.
  if (iCursor == (iLenOfLargeText - 1) )                                              // Reset variable for rollover effect.
  {
    iCursor = 0;
  }
  lcd1.setCursor(0,iLineNumber);
  lcd2.setCursor(0,iLineNumber);
  if(iCursor < iLenOfLargeText - 32)                                                  // This loop executed for normal 16 characters.
  {
    for (int iChar = iCursor; iChar < iCursor + 16 ; iChar++)
    {
      lcd1.print(LargeText[iChar]);
    }
    for (int iChar = iCursor + 16 ; iChar < iCursor + 32 ; iChar++)
    {
      lcd2.print(LargeText[iChar]);
    }
  }
  else
  {
      for (int iChar = iCursor; iChar < (iLenOfLargeText - 1) ; iChar++)                //  This code takes care of printing characters of current string.
      {
        if(16 > (iChar - iCursor))
        {
          lcd1.print(LargeText[iChar]);
        }
        else
        {
          lcd2.print(LargeText[iChar]);
        }
      }
      for (int iChar = 0; iChar <= 32 - (iLenOfLargeText - iCursor); iChar++)           //  Remaining characters will be printed by this loop.
      {
        
        if(16 > (32 - (iLenOfLargeText - iCursor)))
        {
          lcd2.print(LargeText[iChar]);
        }
        else
        {
          if( ((32 - (iLenOfLargeText - iCursor)) - 16) >=  iChar)
          {
            lcd1.print(LargeText[iChar]);
          }
          else
          {
            lcd2.print(LargeText[iChar]);
          }
          
        }  
      }
  }
  iCursor++;
}