Using EEPROM with Arduino

So, what’s the deal with EEPROM ? It’s this cool type of non-volatile memory that you’ll find in microcontrollers like the Mega, ST, and TI, and the best part is it keeps your data safe even when the power goes off.
Depending on the microcontroller, the size of the EEPROM can be different – for instance, the Arduino Uno and ATmega328P come with 1 KB , while the ATmega68 has 512 bytes , and the Arduino Mega boasts a whopping 4 KB .
If you’re getting into managing EEPROM, the EEPROM library in Arduino makes it super simple.
Just remember to include this library in your project to get started.
It’s pretty handy to use the serial interface to peek into and adjust your EEPROM, especially with those example scripts they provide..

Let’s dive into EEPROM with our Arduino! First up, the EEPROM clear function is your go-to for resetting the EEPROM – we’ll show you how it works with an LED and some serial communication.
Now, the Arduino Uno’s EEPROM holds 1024 bytes of storage, and thanks to the library, you don’t have to worry about hardcoding anything.
Just remember, when working with EEPROM, you need to stick to that memory range of 0 to 1023 ; it’s super important! If you want a fresh start, you can easily initialize the EEPROM to zero for that full range.
Plus, there are two handy ways to write and read from EEPROM: you can go byte by byte or choose to work with a specific data type .
Oh, and don’t forget – we’re kicking things off with two integer variables: A is hanging out at three, while B is sitting at zero..

When you’re working with EEPROM, the first step is the write process.
You place a value, let’s say A , into EEPROM and then pull it back out into B to make sure everything’s accurate.
For those using an Arduino Uno, keep in mind that the specific memory address is 1023 , but for the sake of demo, we usually stick to address zero .
You might use an example byte value like 255 to see how it works.
The data retrieval happens through an EEPROM array , which is pretty handy.
Just make sure you’re following the upload instructions, which include a line like “zero CDR print Ln P”.
And before you kick things off, it’s super important to clear any previous data and press that reset button on your Arduino board carefully!.

So, let’s kick things off with a quick overview of using EEPROM with Arduino.
When you store the value 3 at address zero , you’re basically setting the scene for later retrieval.
Once you read it back, you’ll pop that value into a variable called B to see if everything went smoothly.
Now, here’s a handy tip: instead of using the regular write command, you might want to opt for the update command.
This little gem only writes if the new value is different, which saves you time and helps prolong the lifespan of your EEPROM.
Just a heads-up, writing to EEPROM takes around 3.3 ms and can handle about 100,000 cycles before it starts wearing out.
Oh, and don’t worry, when you switch to the update command, the result stays the same—yep, still 3 ! Plus, whether you’re writing and reading data in byte units or even converting it to float , methods like put and get make managing different data types a breeze..

So, let’s chat about managing data types in EEPROM using Arduino! First off, when you’re dealing with a float data type, it takes up four bytes, which means you’ve got to handle those four bytes just right.
For instance, if you want to store the value 3.14, you can easily save it in that 4-byte format.
The nifty update command helps you write in byte units, and if you’ve got arrays, they make block writing super simple.
You’ll often use EEPROM get and put to manage your data neatly according to specific structures.
And speaking of structures, they let you work with more complex data types like floats in an organized way.
So, to insert and retrieve these structured values, just remember to use the put and get functions effectively.
If you want to dive deeper, don’t forget that you can also manage your data on a byte-by-byte level with those same commands!.

So, let’s talk about EEPROM tampering detection! First up, there’s CRC or Cyclic Redundancy Check, which is a handy way to confirm if anyone’s messed with your EEPROM data.
We even provided a file example that walks you through the entire EEPROM and CRC process.
When you try out the CRC32 example, you’ll see it spits out a hex byte value of 0x26091AA1 .
The EEPROM size we’re looking at here is 10241 KB , which is pretty substantial.
By keeping track of the initial CRC hex value, you can check back later to make sure everything’s still intact; any shift in that hex value suggests some tampering might have happened.
And stick around, because we’ll wrap things up with a sneak peek at upcoming content, particularly on how to handle EEPROM with Arduino!.