#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C LCD(0x00, 0, 0); // temporary

String TextLine1 = "";
String TextLine2 = "";
String TextLine3 = "";
String TextLine4 = "";
int t[] = {};
int i = 0;

bool tryConnect(uint8_t address) {
  byte error;
  Wire.beginTransmission(address);
  error = Wire.endTransmission();
  if (error == 0) {
    return true;
  }
  return false;
}

byte getI2cAddress() {
  byte error, address;
  for(address = 1; address < 127; address++) {
    Wire.beginTransmission(address);
    error = Wire.endTransmission();
    if (error == 0) {
      Serial.print("127/");
      Serial.print(address);
      Serial.println(" is working!!!");
      return address;
    } else {
      Serial.print("127/");
      Serial.print(address);
      Serial.println(" is not working");
    }
  }
  return 0;
}

byte lcdAddress;

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(9600);
  Serial.println("\n"); // new empty line
  Wire.begin();
  lcdAddress = getI2cAddress();

  if (lcdAddress != 0) {
    LCD = LiquidCrystal_I2C(lcdAddress, 20, 4);
    LCD.begin(20, 4);
    LCD.backlight();
    LCD.clear();
    Serial.println("LCD is started and ready!");
    digitalWrite(LED_BUILTIN, LOW);
  } else {
    Serial.println("LCD isn't started");
    digitalWrite(LED_BUILTIN, HIGH);
  }

  Serial.println("write here");

}

void loop() {
  LCD.setCursor(0, 0);
  LCD.print(TextLine1);
  LCD.setCursor(0, 1);
  LCD.print(TextLine2);
  LCD.setCursor(0, 2);
  LCD.print(TextLine3);
  LCD.setCursor(0, 3);
  LCD.print(TextLine4);

  if (Serial.available()) {
    t = [];
    i = 0;
    while (Serial.available()) {
      char data = Serial.read();
      t[i] = data;
      i++;
    }
    char data = Serial.read();
    if (data != "") {
      TextLine1 = TextLine2;
      TextLine2 = TextLine3;
      TextLine3 = TextLine4;
      TextLine4 = String(t);
    }
  }
}