Arduino Tutorial 10: Save Data with EEPROM!

Did you know your Arduino has the ability to save data locally and permanently such that you can access it after you power cycle the unit? It does, and this is called the EEPROM. Although your Arduino can't store as much as a SD card, the 1kB of an Uno or 4kB of a MEGA2560 gives you more flexibility in your projects without having to get add-ons.

The supporting content and code used in this tutorial can be found at my website at:

[t.c.nevzatozdogru]

Dear Baran-Harper,
E2eprom information you provide was very helpful for me.
Many many thanks.

[EgyptFishingVideos]

Lovely! Thanks.
Will try it with the Nano as well and see what happens!

[EVERY.CIRCUIT]

Nice, you taught us the way to store bits, but how about saving the words and decimal numbers?

[codingspace]

you are awesome...I watch a lot of videos about eeprom and not get the idea but your video is great...many thanks and God bless you bro

[AhmedAli-snty]

you always make me understand your topics clearly
thanks man make more like this

[agentrfr]

Cool video

Just a question though, since your loop currently doesn't check EEPROM state before writing, wont it write every loop while the button is pressed? Even if it takes 5ms per loop, holding the button for 1 second would do 200 writes to the EEPROM, or rather that EEPROM is useless after a total of 500 1 second button presses :(

[JimmiJohnJunnior]

I'd suggest to anyone trying this to put the read from EEP read in the setup and make two more if statements that compare the lastPress before writing to EEP so that you wont waste any cycles from your arduino.

[timothymanz]

why perform READ before WRITE as EEPROM preservation? would you call a function like UPDATE in order to only write when data is actually different?

[mohammadjawadbarati]

hi Alexander
thank you for this video, i have question, when we write for number one, for example " uint8_t addressOfEEPROMnumberOne = 100; " and then save a float number one for example "22.34", for next number ( number two) for example "25.96", What number should I put in the new address?
"uint8_t addressOfEEPROMnumberTwo= ? ;"

[GeoffPritchett]

cool now how do you write to eeprom when using timer interrupts....nothing works just crashes on button press when a timer is enabled to an ISR alarm

[sobhanmovassagh]

hi your tutorial is very usefull, tank you. but in your site the video for this tutorial (tutorial 10) is wrong. you linked video of tutorial 5 to tutorial 10.

[kouameherve]

good tutorial, now can you make it with one EEPROM external 24C08 for exemple

[paulg.]

very nice and clear tutorial, thanks!

[trungnguyenthanh]

Can you show me how to study and save latitude and longtitude by button to eeprom? Thanks

[Kyles_Granado]

can you pls explain further what is uint8_t EEPROM = 0; in line 12

[springwoodcottage]

Super useful to me, thank you for sharing!

[dilshankasthuriarachchi]

Hellooo could you please tell me how does the any data save to EEPROM in arduino? i mean, servo motor positioning, Gsm module

[bikrammukherjee]

thanks for this video....but how to save bluetooth past data in arduino? when the power down and after power on the arduino fetch the past data of bluetooth
please help in this matter...

[diyhub]

How to delete or clear save data in eeprom? what will happen if i uploaded a new code? does the data stays in the arduino even if i change or upload a new sketch/code?

[DwiNoviantoUntidar]

How to save 4 variables
I need to save second, minutes & days.
thanks.