Reading and Writing Serial EEPROMs

Contributors: Nate, Nick Poole
Favorited Favorite 4


EEPROM, or Electrically Erasable Programmable Read-Only Memory, is a type of device that allows you to store small chunks of data and retrieve it later even if the device has been power cycled. A lot of modern microcontrollers – such as the ATmega328 – contain some built-in EEPROM, but that doesn’t mean that you can’t add more! Serial EEPROM devices like the Microchip 24-series EEPROM allow you to add more memory to any device that can speak I²C. Today we’re going to learn how to read and write serial EEPROM devices using Arduino.

Image of an EEPROM IC with a US quarter for size comparison

Image of an EEPROM IC with a US quarter for size comparison.

Suggested Reading

Before continuing with this guide, we recommend you be somewhat familiar with the concepts in the following tutorials:

How to Use a Breadboard

Welcome to the wonderful world of breadboards. Here we will learn what a breadboard is and how to use one to build your very first circuit.

What is an Arduino?

What is this 'Arduino' thing anyway?

Integrated Circuits

An introduction to integrated circuits (ICs). Electronics' ubiquitous black chips. Includes a focus on the variety of IC packages.


An introduction to I2C, one of the main embedded communications protocols in use today.