3variable.ino

#include <Arduino.h>
#include <EEPROM.h>

const int EEPROM_SIZE = 512; // EEPROM size in bytes
const int MAX_STRING_LENGTH = 50; // Maximum string length

void setup() {
  Serial.begin(115200);
  EEPROM.begin(EEPROM_SIZE); // Initialize EEPROM
}

void loop() {
  int int1 = 123;
  int int2 = -456;
  String myString = "Hello, EEPROM!";

  // Write data to EEPROM
  writeDataToEEPROM(int1, int2, myString);

  // Read back and print data from EEPROM
  int readInt1, readInt2;
  String readString;
  readDataFromEEPROM(readInt1, readInt2, readString);
  Serial.print("Integers read from EEPROM: ");
  Serial.print(readInt1);
  Serial.print(", ");
  Serial.println(readInt2);
  Serial.print("String read from EEPROM: ");
  Serial.println(readString);

  delay(1000);
}

void writeDataToEEPROM(int int1, int int2, const String &myString) {
  int address = 0;
  
  // Write integers to EEPROM
  EEPROM.put(address, int1);
  address += sizeof(int1); // Move to the next address
  EEPROM.put(address, int2);
  address += sizeof(int2); // Move to the next address
  
  // Write string to EEPROM
  for (int i = 0; i < myString.length(); ++i) {
    EEPROM.write(address + i, myString[i]);
  }
  EEPROM.write(address + myString.length(), '\0'); // Null-terminate the string
  
  // Commit changes to EEPROM
  EEPROM.commit();
}

void readDataFromEEPROM(int &int1, int &int2, String &myString) {
  int address = 0;
  
  // Read integers from EEPROM
  EEPROM.get(address, int1);
  address += sizeof(int1); // Move to the next address
  EEPROM.get(address, int2);
  address += sizeof(int2); // Move to the next address
  
  // Read string from EEPROM
  char buffer[MAX_STRING_LENGTH];
  int bytesRead = 0;
  while (true) {
    char character = EEPROM.read(address + bytesRead);
    if (character == '\0' || bytesRead >= MAX_STRING_LENGTH - 1) {
      break;
    }
    buffer[bytesRead++] = character;
  }
  buffer[bytesRead] = '\0'; // Null-terminate the string
  myString = String(buffer);
}

esp32-save-read-2-int.ino

#include <Arduino.h>
#include <EEPROM.h>

const int EEPROM_SIZE = 512; // EEPROM size in bytes

void setup() {
  Serial.begin(115200);
  EEPROM.begin(EEPROM_SIZE); // Initialize EEPROM
}

void loop() {
  int int1 = 123;
  int int2 = -456;

  // Write integers to EEPROM
  writeIntsToEEPROM(int1, int2);

  // Read back and print integers from EEPROM
  int readInt1;
  int readInt2;
  readIntsFromEEPROM(readInt1, readInt2);
  Serial.print("Integers read from EEPROM: ");
  Serial.print(readInt1);
  Serial.print(", ");
  Serial.println(readInt2);

  delay(1000);
}

void writeIntsToEEPROM(int int1, int int2) {
  // Check if EEPROM has enough space
  if (sizeof(int1) * 2 <= EEPROM_SIZE) { // Check if there's enough space for both integers
    // Write integers to EEPROM
    int address = 0;
    EEPROM.put(address, int1);
    address += sizeof(int1); // Move to the next address
    EEPROM.put(address, int2);

    // Commit changes to EEPROM
    EEPROM.commit();
  } else {
    Serial.println("EEPROM does not have enough space to save the integers.");
  }
}

void readIntsFromEEPROM(int &int1, int &int2) {
  // Read back integers from EEPROM
  int address = 0;
  EEPROM.get(address, int1);
  address += sizeof(int1); // Move to the next address
  EEPROM.get(address, int2);
}