// LCD1602 to Arduino Uno connection example
#include <LiquidCrystal.h>

int potpin = 0;
int val;

LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

void setup() {
  lcd.begin(16, 2);
  // you can now interact with the LCD, e.g.:
  lcd.print("Voltmeter");
}

void loop() {
  // ...
  lcd.setCursor(0, 1);
  val = analogRead(potpin); // 0 to 1023
  float voltage = map(val, 0, 1023, 0, 500)/100.00;
  String display = String(voltage) + " (V)";
  lcd.print(display);
}