Arduino/libraries/NewliquidCrystal/examples/HelloWorld_byVac/HelloWorld_byVac.ino

//#include <LiquidCrystal.h>
//LiquidCrystal lcd(4, 7, 8, 9, 10, 11, 12);

#include <Wire.h> 
//#include <LiquidCrystal_I2C_ByVac.h>
//LiquidCrystal_I2C_ByVac lcd(0x21); 

//#include <LiquidCrystal_I2C.h>
//LiquidCrystal_I2C lcd_1(0x27,2,1,0,4,5,6,7,backlight_pin,POSITIVE); // DF Robots

//#include <LiquidCrystal_SR.h>
//LiquidCrystal_SR lcd(14,15,4);

#include <LiquidCrystal.h>
//LiquidCrystal lcd(4, 7, 8, 9, 10, 11, 12);
LiquidCrystal lcd(8, 9, 4, 5, 6, 7); // LCD Shield

uint8_t bell[8]  = {0x4,0xe,0xe,0xe,0x1f,0x0,0x4};
uint8_t note[8]  = {0x2,0x3,0x2,0xe,0x1e,0xc,0x0};
uint8_t clock[8] = {0x0,0xe,0x15,0x17,0x11,0xe,0x0};
uint8_t heart[8] = {0x0,0xa,0x1f,0x1f,0xe,0x4,0x0};
uint8_t duck[8]  = {0x0,0xc,0x1d,0xf,0xf,0x6,0x0};
uint8_t check[8] = {0x0,0x1,0x3,0x16,0x1c,0x8,0x0};
uint8_t cross[8] = {0x0,0x1b,0xe,0x4,0xe,0x1b,0x0};
uint8_t retarrow[8] = {	0x1,0x1,0x5,0x9,0x1f,0x8,0x4};


const byte backLightpin = 5; 
//const byte backLightpin = 10; 
const byte contrast_pin = 6;

void setup () {
   //lcd.begin(16,2);   
   lcd.begin(20,4);
   lcd.clear();
  // lcd.backlight();
  //   lcd.setBacklightPin(3);
   //  lcd.setBacklight(1);
   pinMode(backLightpin, OUTPUT);
   analogWrite(backLightpin, 210);
   pinMode(contrast_pin, OUTPUT);
   analogWrite(contrast_pin, 40);
   lcd.createChar(0, bell);
   lcd.createChar(1, note);
   lcd.createChar(2, clock);
   lcd.createChar(3, heart);
   lcd.createChar(4, duck);
   lcd.createChar(5, check);
   lcd.createChar(6, cross);
   lcd.createChar(7, retarrow);
  }

// display all keycodes
void displayKeyCodes(void) {
  uint8_t i = 0;
  while (1) {
    lcd.clear();
    lcd.print("Codes 0x"); lcd.print(i, HEX);
    lcd.print("-0x"); lcd.print(i+16, HEX);
    lcd.setCursor(0, 1);
    for (int j=0; j<16; j++) {
      lcd.write(i+j);
    }
    i+=16;
    
    delay(10000);
  }}    
    

void loop () {
  displayKeyCodes();
}