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.
198 questions
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Arduino simple PowerUp Counter
I am from Argentina.
I am making a kind of project for my car, and one of the many functions I am planning, is to check how many times the Arudino has been powered up.
I was thinking of a simple ...
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External EEPROM Read and Write Issues: Junk Values in I2C Communication
I have an ESP32 controller and am using AT24C1024 for communication. In my code, I am trying to access an external EEPROM at positions writing data from 0 to 10000 position data is = '1'. However, ...
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String or unsigned char to uint8_t
I'm attempting to save a string to EEPROM of an ESP8266 radio and then read it back before I encrypt the data (evenutally I would like to save the encrypted data but I'm simplifing things at the ...
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Problem saving "char" variable to EEPROM on ESP32
I am making a project, in which I need to store the WiFi credentials to the EEPROM. For now, I am able to store a bool array in the EEPROM, but I am not able to store the char variables as the ESP32 ...
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Is the EEPROM the best alternative for store non-volatile values with Arduino?
SD-cards are capable of store values even if it is turned off.
I don't know what is the time that a EEPROM can keep a value in it's memory, but of course are better than the volatile memory.
There are ...
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changing a single bit in an arduino EEPROM byte
In my code I have a number of boolean flags that tell me if data has been written to specific places in the EEPROM. I need to save these flags to the EEPROM and recover them on a restart.
Is the ...
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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 ...
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manage some output based on some parameter and rtc
i'm trying to create a program that given a configuration (i've used multiple struct nested) i need in loop() to check for each output if they need to be on or off and set the output accordingly
let ...
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Attiny84 with external eeprom-write and read beyond 255
Just starting with external EEPROM and ATTiny's. I am successfully writing and reading to the 24LC64 chip using the following code with TinyWireM (thanks to other help on the forums). However, I ...
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Bitwise Operator in Arduino Code Question
What is the below Arduino code doing?
I am not familiar with the '+' with regard to bitwise operations. Just getting familiar with this stuff.
return ((four << 0) & 0xFF) + ((three << ...
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Can I run Arduino code on a 6502?
I've been doing projects with the arduino boards for a long time and accordingly also with the libs from adafruit etc. But that was too boring for me and I wanted to get more into the matter, so I ...
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How does erasing the EEPROM work?
The datasheet for the ATmega328P contains this table, which describes bits 4 and 5 of EECR:
EEPM1
EEPM0
Programming Time
Operation
0
0
3.4ms
Erase and write in one operation (atomic operation)
0
1
1....
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Arduino IDE EEPROM put() then read() returns different data on ESP32
I'm trying to understand how to read/write a UID struct from miguelbalboa to EEPROM to persist a card ID across system restarts on my ESP32-S3 through the Arduino IDE. I expected Put/Get/Read to be ...
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What is wrong with the way I write and or read the EEPROM adresses?
Consider:
#include <EEPROM.h>
byte guifactor1 = 1;
byte guifactor2 = 2;
byte guifactor3 = 3;
byte guifactor4 = 4;
byte guifactorgas = 5;
byte guifactorwater = 6;
volatile unsigned long ...
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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 ...
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