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Write any data type or object to the EEPROM.


EEPROM.put(address, data)


address: the location to write to, starting from 0 (int)

data: the data to write, can be a primitive type (eg. float) or a custom struct


A reference to the data passed in


This function uses EEPROM.update() to perform the write, so does not rewrites the value if it didn't change.


    eeprom_put example.

    This shows how to use the EEPROM.put() method.
    Also, this sketch will pre-set the EEPROM data for the
    example sketch eeprom_get.

    Note, unlike the single byte version EEPROM.write(),
    the put method will use update semantics. As in a byte
    will only be written to the EEPROM if the data is actually

    Written by Christopher Andrews 2015
    Released under MIT licence.

#include <EEPROM.h>

struct MyObject {
  float field1;
  byte field2;
  char name[10];

void setup() {

  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only

  float f = 123.456f;  //Variable to store in EEPROM.
  int eeAddress = 0;   //Location we want the data to be put.

  //One simple call, with the address first and the object second.
  EEPROM.put(eeAddress, f);

  Serial.println("Written float data type!");

  /** Put is designed for use with custom structures also. **/

  //Data to store.
  MyObject customVar = {

  eeAddress += sizeof(float); //Move address to the next byte after float 'f'.

  EEPROM.put(eeAddress, customVar);
  Serial.print("Written custom data type! \n\nView the example sketch eeprom_get to see how you can retrieve the values!");

void loop() {
  /* Empty loop */

See also

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The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.