#include <LiquidCrystal_I2C.h>
#include <Servo.h>
Servo myServo;
LiquidCrystal_I2C lcd(0x27, 20, 4);
#define pot A0
void setup() {
  myServo.attach(12);
  lcd.init();
  lcd.backlight();
  pinMode(pot, INPUT);// put your setup code here, to run once:
  myServo.write(0);
  lcd.setCursor(0, 0);
  lcd.print("servo angle");
}

void loop() {
  int potval = analogRead(pot) / 255;
  myServo.write(map(potval, 0, 4, 0, 179));

  // put your main code here, to run repeatedly:
  switch (potval) {
    case 0 :
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("servo angle");

      lcd.setCursor(0, 1);
      lcd.print("0");

      break;
    case 1:
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("servo angle");

      lcd.setCursor(0, 1);
      lcd.print("72");
      break;
    case 2:
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("servo angle");

      lcd.setCursor(0, 1);
      lcd.print("108");
      break;
    case 3:
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("servo angle");

      lcd.setCursor(0, 1);
      lcd.print("144");
      break;
    case 4:
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("servo angle");

      lcd.setCursor(0, 1);
      lcd.print("180");
      break;
    default:
      lcd.clear();
      lcd.setCursor(0, 1);
      lcd.print("error");
  }
  delay(1000);
}