#include <EEPROM.h>

#define EEPROM_SIZE 512 // Adjust the size as per your requirement

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    delay(10);
  }

  String textToSave;

  // Prompt user to enter a string
  Serial.println("Enter a string to save in EEPROM:");

  // Wait for user input
  while (!Serial.available()) {
    delay(10);
  }

  // Read the string from Serial Monitor
  while (Serial.available()) {
    char c = Serial.read();
    if (c == '\n' || c == '\r') { // Check for newline or carriage return
      break;
    }
    textToSave += c;
  }

  // Read the existing string from EEPROM
  String storedText = readStringFromEEPROM(0);

  // Check if the new string differs from the existing one
  if (textToSave != storedText) {
    // Save the string to the EEPROM only if it's different
    saveStringToEEPROM(0, textToSave);
    Serial.println("String saved in EEPROM.");
  } else {
    Serial.println("String is the same as the previous one in EEPROM.");
  }

  // Read and display the stored string from the EEPROM
  storedText = readStringFromEEPROM(0);
  Serial.print("Stored Text in EEPROM: ");
  Serial.println(storedText);
}

void loop() {
  // Your main code here
}

void saveStringToEEPROM(int address, String data) {
  EEPROM.begin(EEPROM_SIZE); // Begin EEPROM

  for (unsigned int i = 0; i < data.length(); i++) {
    if (EEPROM.read(address + i) != data[i]) {
      EEPROM.write(address + i, data[i]);
    }
  }

  if (EEPROM.read(address + data.length()) != '\0') {
    EEPROM.write(address + data.length(), '\0'); // Null-terminate the string
  }

  EEPROM.commit(); // Commit changes
  EEPROM.end(); // End EEPROM
}

String readStringFromEEPROM(int address) {
  EEPROM.begin(EEPROM_SIZE); // Begin EEPROM

  char charRead = EEPROM.read(address);
  String readString = "";

  while (charRead != '\0' && address < EEPROM_SIZE) {
    readString += charRead;
    address++;
    charRead = EEPROM.read(address);
  }

  EEPROM.end(); // End EEPROM
  return readString;
}