#include <LiquidCrystal.h>
LiquidCrystal lcd(A0, A1, 4, 5, 6, 7);

int j;
int i;

byte block1[8]
{
  B00000,
  B00000,
  B00000,
  B01100,
  B00011,
  B01101,
  B01100,
  B00000,
  };

byte block2[8]
{
  B00000,
  B00000,
  B00100,
  B11110,
  B11000,
  B10110,
  B00110,
  B00000,
};

void setup()
{
  lcd.begin(16,2);
  lcd.createChar(1, block1);
  lcd.createChar(2, block2);
}

void animate()
{
  lcd.setCursor(i,j);
  lcd.write(1);
  lcd.write(2);
  delay(1000);
  lcd.clear();
  }

void loop()
{
  for(i=-1; i<=15; i++)
  {
      animate();

      if(i == 15 && j == 0)
      {
        i = -1;
        j = 1;
      }
      else if(i == 15 && j == 1)
      {
        i = -1;
        j = 0;
      }
    }
    animate();
}