ESP8266 EEPROM seems not working, saved data are different when I try to read them

Question

I'm working on project which require to save some data into the EEPROM. As I read online the ESP8266 has no real EEPROM, it use a section of FLASH just after the SPIFFS. Due to this read/write is quite different from standard Arduino, you need to call EEPROM.commit(). You also have to call EEPROM.begin(size) (I used size = 512) before start to use it.

I follow different tutorials online and I made some tests but it seems not working at all. When I try to save a value and then read it, values are different. I tried with

EEPROM.write(..)
...
EEPROM.read(..)

and with

EEPROM.put(..)
...
EEPROM.get(..)

but nothing change.

Is there any configuration on the board I need to set into Arduino IDE/Board Configuration?

EDIT: here's the code

void setup() 
{
 Serial.begin(9600);
 Serial.println();
 EEPROM.begin(512);
 EEPROM.write(0, 62);
 EEPROM.write(10, 103);
 //EEPROM.commit();
 EEPROM.end();
 Serial.print("Read at 0:"); Serial.println(EEPROM.read(0), DEC);
 Serial.print("Read at 10:"); Serial.println(EEPROM.read(10), DEC);
}

I always read 0 in the output.

• dandavis: why not just use SPIFFS? it's way simpler, far larger, and better organized.
• Noisemaker: @dandavis I only need to store a few bytes, use a file system seems too much 'expensive' to achieve this simple task.
• dandavis: It's not that expensive, and in fact, it has wear-leveling, which is (potentially) a huge long-term reliability benefit, especially when most of your blocks will be empty. It's not really a full file system, there's not even paths (just names), so it's more a fast key/value store of it's own right. I would try it and see if it bogs down your project; I can't image it would be much worse than EEPROM unless your doing something that will wear out either...
• Juraj: you can read only between begin and end. it works with memory image. begin allocates the in-memory image. commit writes it to flash. end commits and deletes the memory image
• Noisemaker: @Juraj thanks a lot! For me it's the best answer. It works and now I understande the reason. Btw it is not very well documented this procedure.

Answer 1

You can read the emulated EEPROM only between begin and end. It works with memory image.

• begin allocates the in-memory image.
• commit writes it to flash.
• end commits and deletes the memory image.

Answer 2

Here is some ESP8266 example code to store and read strings from EEPROM data:

#include <EEPROM.h>
void writeString(char add,String data);
String read_String(char add);
void setup() {
 // put your setup code here, to run once:
 Serial.begin(9600);
 EEPROM.begin(512); // Note::
 String data = "Hello World";
 Serial.print("Writing Data:");
 Serial.println(data);
 writeString(10, data); //Address 10 and String type data
 delay(10);
}
void loop() {
 // put your main code here, to run repeatedly:
 String recivedData;
 recivedData = read_String(10);
 Serial.print("Read Data:");
 Serial.println(recivedData);
 delay(1000);
}
void writeString(char add,String data)
{
 int _size = data.length();
 int i;
 for(i=0;i<_size;i++)
 {
 EEPROM.write(add+i,data[i]);
 }
 EEPROM.write(add+_size,'0円'); //Add termination null character for String Data
}
String read_String(char add)
{
 int i;
 char data[100]; //Max 100 Bytes
 int len=0;
 unsigned char k;
 k=EEPROM.read(add);
 while(k != '0円' && len<500) //Read until null character
 { 
 k=EEPROM.read(add+len);
 data[len]=k;
 len++;
 }
 data[len]='0円';
 return String(data);
}