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Questions tagged [eeprom]

Electronically Erasable ROM is a type of memory available on most boards. It is used for storing persistent data. Use the tag for questions about the EEPROM library or the hardware.

197 questions
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5 answers

What is the real lifetime of EEPROM?

ATMEL says the cell lifetime of an EEPROM cell is about 100,000 write cycle/ cell. Is this actually how the EEPROM performs in the wild? If I do not change the value of a cell, does this stress the lifetime? For example, if I write the value 0xFF to…
Marlon Abeykoon
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EEPROM endurance and page size

I would like to estimate the effective (minimum) endurance of the EEPROM of the Arduino in terms of single-byte writes. The datasheet of the ATmega used on many Arduino boards says (page 20): The ATmega48A/PA/88A/PA/168A/PA/328/P contains…
fuenfundachtzig
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6
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Arduino digitalWrite 1 or 0 instead of HIGH or LOW

Is it ok to use digitalWrite(pin, 1) instead of digitalWrite(pin, HIGH) or digitalWrite(pin, 0) instead of digitalWrite(pin, LOW) I want it that way to make the coding lesser because I save values on EEPROM with 1's and 0's. So if I want to use…
Sam San
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2 answers

Can I improve EEPROM lifetime by not changing bits?

In my current project I need to store the current elapsed time in hours to retrieve it in case of power loss. Since I am using a Arduino Nano I would ideally like to use the built in EEPROM without additional hardware. The written values and their…
maxmilgram
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4
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3 answers

Possible to store variables directly in EEPROM?

Is it possible to store a variable directly in EEPROM and retrieve it without needing to use a library? I'm building a project that can change the colour of an RGB LED and I want to store the colour in a non-volatile memory space, but I was…
Raceimaztion
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4
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2 answers

Is EEPROM persisted across program flashes?

If I use EEPROM.write(someAddr, someValue) to write a value to an address, how long will that value "stick" to that address before being lost? If I were to power down the Arduino, flash a whole new program to it, and power it on, could I still…
smeeb
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How to save a float variable to the EEPROM?

This is my first post here and I'm hoping there are some Arduino hobbyists here to help me. Does anyone here know how to save a float variable directly to the EEPROM? If so, could you have a look at the program I wrote and hopefully explain how it…
Jessey Montgomery
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4 answers

How do you write to a free location on an external EEPROM?

I want to log GPS positions to an external EEPROM over I2C. For example: Latitude: 51.0000 Longitude: 4.0000 If I remove the decimal place then each of these addresses would consume up to two bytes each. My question is: How can I log each new set of…
blarg
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Write faster on AT24C32

I'm using AT24C32 EEPROM chip from ATmel. I found code that will write and read bytes from chip. Code writes and reads bytes correctly and without any problem. But I have to write few 8-byte values often(every 10-15 seconds). I did "cut" those…
Pararera
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1 answer

EEPROM library throwing errors

I've included in my sketch and am trying to run a simple sketch that just does EEPROM.write(0,4); followed by a println of EEPROM.read(0); However, it won't compile. It keeps telling me there is an error, and that I'm making a "request for member…
Michael Stachowsky
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Splitting a string read from Serial into parts

Is there any method with which I can split a string given by Serial.read() into an array of 3 items: [command, address, message], to write it to EEPROM? Thanks.
Iem-Prog
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EEPROM write time

I will implements an emergency backup feature before power off, on Arduino Mega 2650. Arduino is powered by capacitor, for the time (I hope) of the EEPROM write. On AVR2650 Datasheet is reported that the typical EEPROM writing time is 3.3ms. But…
EffegiWeb
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Most efficient way to store number in EEPROM?

I would like to store temperature readings in eeprom, the value from -55.00 to 125.99. What is the most space efficient way to store these numbers with two significant digits along with epoch timestamp? Thanks
Du D.
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0
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2 answers

How EEMEM maps the variables? (avr/eeprom.h)

I can store and restore my data with avr/eeprom.h if I don't change the sketch. I have a sketch that stores the data. After power cycle of the device the data are fine. If I change the sketch with Serial.print statements (I want to re-read the data…
krg
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0
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2 answers

ESP8266 using EEPROM to store a value of 100,000

I'm using Wemos mini in my project. I wish to store a Boolean value in cell #0, which changes every boot. Since writing to EEPROM is limited to roughly 100,000 cycles - I want to store in cell #1 the amount of writing cycles done so far, so when…
guyd
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