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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.

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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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5 votes
2 answers
119 views

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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0 votes
1 answer
104 views

Why is EEPROM commit not registering int values?

if(jsonDoc["delayOn"].as<int>() <= 255 && jsonDoc["delayOff"].as<int>() <= 255 && jsonDoc["delayUnitOn"].as<int>() <= 2 &&...
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2 votes
3 answers
144 views

why is my char array empty

following sketch will run totally fine and as expected : #include <Wire.h> #include "SparkFun_External_EEPROM.h" ExternalEEPROM ExtEEPROM; char username[33] = ""; char ...
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1 answer
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Erratic behaviour using a DUE with the Microchip 24FC64 EEPROM chip?

I am attempting to read and write from/to an EEPROM chip, and have got access to this 64 kbit device. It appears I can write to the device and read from it, but there appears to be some strangeness ...
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  • 293
0 votes
1 answer
84 views

How to set the eeprom initial value when flashing an ESP32

As I use the EEPROM to persist data such as for provisioning the WiFi (SSID and password), I'd like to make sure that the very first time the ESP32 runs, it finds the initial '\0' for the SSID so that ...
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2 votes
2 answers
56 views

Read & Write to EEPROM

I need to implement EEPROM Read & Write functionality to my project. I've been learning how to use the EEPROM on the last few days, however I'm struggling to Read & Write Strings to EEPROM. ...
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1 vote
1 answer
66 views

How to change variable/sketch through a GUI

Over the past few months, I've been working on a wearable computer mouse using an Arduino and a 9-dof sensor. Most of the sketch is complete, and works as expected. Recently, I started investigating ...
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2 votes
2 answers
104 views

UNO's Internal EEPROM "read" returns incorrect values when it precedes "write"

I am an Arduino instructor and I was preparing some material on the utilization of the Arduino UNO's internal EEPROM when I encountered a problem. The problem is, I am trying to show the original ...
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1 vote
0 answers
262 views

Arduino Mega as a EEPROM Programmer for Winbond W29EE011 memories

I'm trying to use my Arduino Mega as an EEPROM memory writer. For this project, besides my Arduino Mega, I use an SD Card module, an LCD display and two push buttons to handle the events. Inside the ...
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1 vote
1 answer
299 views

nRF52 non-volatile storage/recall of a variable - is there a simple solution?

I have an Arduino program written for the nRF52 with which runs for a pre-set time-value (i.e. 2 minutes) before shuts off automatically. The variable time-value can be changed via BLE-write by the ...
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1 vote
0 answers
71 views

Why does this piece of code overflow at 255?

Im having a problem where i got unsinged long variable and i need to increment it in eeprom everytime setup starts and it overflows at 255 back to 0. unsigned long NumberOfBoots = 0UL; #define ...
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1 vote
0 answers
30 views

Reading a flash ROM chip (M45PE20) through SPI with an ATMEGA 2560 -- output only FF's

I'm trying to communicate through SPI to a Flash ROM chip (M45PE20) with an ATMEGA 2560. I'm looking to read the data off the chip, but the output I'm getting is nothing but FF's. I've checked my ...
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2 votes
1 answer
70 views

Serial.println won't format DEC

This is weirding me out. So I wrote to the EEPROM and I would like to read from the address and format it in Base 10, err... Decimal. The normal number thingy that's not ASCII. But it keeps returning ...
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0 votes
1 answer
109 views

does EEPROM reset itself when a new code is uploaded?

I have a Nodemcu with which i'm doing a project. So whenever there is a power loss i want values of some of the variables to not be reset, because of that im trying to store the values in EEPROM of ...
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1 vote
1 answer
101 views

Neo 6m outputting something i as a noob can't understand

So i connected my ublox neo 6m gps breakout board GY-GPS6MV2 to the arduino software serial and got this result, i used resistors and only supplied 3.3v to the board, gps encode library couldn't give ...
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1 vote
0 answers
81 views

How can I store a value of 1000 over to EEPROM of Arduino Nano?

I need some of your feedback and guidance. In my prototype project powered by Arduino Nano(Space Constraint), it will operate continuously until it reach a maximum of 100 hours. Once it reached 100 ...
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2 votes
3 answers
747 views

How can I read the data stored in EEPROM although is powered OFF based on the simple code I wrote?

I need help regarding on EEPROM library. Based on the code below, for every 2 sec, I want to store the int for increase where it will keep increasing by 1. Then, I upload to my Arduino Nano and open ...
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1 vote
1 answer
63 views

Compiling Assembly Script in External EEPROM to Arduino Code

I'm working on a simple game console, and I'm planning to use a cartridge system using an EEPROM. I know that you can read and write data from an EEPROM, but can you compile the data into executable ...
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5 answers
207 views

Reading from EEPROM and writing to addressable LED with limited connections

UPDATE Clock speed code has been tweaked as per the suggestion from @timemage due to inability for Wire library to reduce to below 30304Hz. Unfortunately problems still persist: Nothing printed out to ...
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0 votes
2 answers
263 views

Programming AT24C16 EEPROM with Arduino Nano

I have been trying to program an AT24C16 EEPROM and have set up a circuit as per the attached image. I have been using the following Arduino code: #include <Wire.h> #define disk1 0x50 /...
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1 vote
1 answer
128 views

EEPROM programmer works with serial monitor but not with pySerial

I'm trying to modify Ben Eater's eeprom programmer to flash a 32K eeprom, since the arduino has 32K of program data total the data wouldn't fit in the program. So I wrote a python program using ...
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2 votes
2 answers
265 views

Where to store critical data in power outage situation on ESP8266

I want to store a counter that is always changing, but I want it to remain and being able to retrieve it on after a power loss. It's only one long number data, but as it is always changing, I don't ...
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  • 21
1 vote
1 answer
469 views

Why isn't this EEPROM.get() working?

I am trying to save a string/char to EEPROM with EEPROM.put() and then get the value, but it doesn't work and I get a blank value when I do a EEPROM.get(). I remember this is how it worked on arduino ...
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  • 242
1 vote
1 answer
612 views

ESP32: best way to embed certificates

I'm using the Arduino framework on an ESP32 based board. The board has an SD card slot, but I'm not going to use it. Anyway, I need to store somewhere the certificates. To the the firmware I've just ...
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  • 265
1 vote
1 answer
349 views

Is it possible to upload and run code from EEPROM during boot time?

I am having problems while writing custom bootloader, so that it uploads code from EEPROM (for now internal, as I have no external memory in my hands) and writes into flash. After ~2 weeks of ...
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1 vote
0 answers
151 views

EEPROM Arduino library for ESP8266 is not working

I am trying to use EEPROM library from Arduino framework for my ESP8266 project (NodeMCU). I am using Atom with Platformio. Initialization of EEPROM is attempted at void setup() in main.cpp: EEPROM....
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1 vote
1 answer
315 views

How to convert my Arduino setup to a PIC setup?

I have an arduino setup with LCD, RTC, EEPROM, Reed Switch, AC/DC Buck Converter, 4X4 Keypad. What PIC IC will let me connect with all these(40 Pins), and yet accept Arduino Code. I don't want to ...
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0 votes
1 answer
142 views

Store & retrieve parameters after sketch update

I have a Generic code for some IOT devices which vary in some parameters ( lets say it is only its MQTT name and subscriptions). Since I use OTA to update sketch, I'm looking for a way to A) write ...
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1 vote
1 answer
154 views

Junk values in EEPROM. while writing large values

Facing an issue while writing a large value (like 2000-5000) to EEPROM using EEPROM.put(). For example, While writing 2000 values to address 5 of EEPROM. Some junk values are written automatically to ...
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0 votes
1 answer
164 views

Error while inputting EEPROM.read() and EEPROM.write()

I am trying to store data in ATmega328 (Arduino Uno) using the following code using tinkercad: #include <EEPROM.h> void setup() { int addr, data=1; Serial.begin(9600); for (addr=0; addr&...
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  • 113
1 vote
1 answer
999 views

Need help with EEPROM not storing array values on ESP8266 after restart

I am struggling through a program. I am trying to store my uploaded string into an array then write that array to EEPROM. I run the program, upload the new array and store it in the EEPROM. all values ...
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-1 votes
1 answer
188 views

EEPROM not consistent over reboot

I'am using a Wemos D1 mini V3.0.0 (esp 8266 core). I tried to save a structure in EEPROM memory but all data are lost when i reboot the board. I am using these basics functions : int cle_verif = ...
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0 votes
2 answers
99 views

the use of the Arduino's EEPROM

I want to know the purpose of using the EEPROM because I can't get it, I mean I know that it can store values for a long time, but I just can't get the goal here #include<EEPROM.h> void setup() ...
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0 votes
2 answers
213 views

Arduino Uno SD card storage

I am interested in storing accelerometer data to an SD card. Since power consumption is the main consideration of my project, it is important to do as few writes to the SD as possible, because the SD ...
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  • 143
2 votes
3 answers
160 views

Arduino Mega keep states after reprogramming

Based on: https://forum.arduino.cc/index.php?topic=440978.0 And some previous experience with Arduinos. What I would like to accomplish here is that I have a 8 channel relay board with the relays in ...
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  • 21
0 votes
2 answers
179 views

store multiple of float type on EEPROM

I have 7 float variables. float temperature, differential, calibration,hta,lta,hha,lha; I want to store them all on the EEPROM memory, how do I calculate the addresses given that there type is ...
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1 vote
0 answers
95 views

ESP8266 EEPROM Reading extra character

I am very very new to ESP Programming. I am trying to store Strings into EEPROM of ESP8266. I am storing the string into eeprom successfully but while reading it from EEPROM extra character 'd' is ...
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0 votes
1 answer
742 views

Managing configurations via EEPROM by writing it with the hex file

I've been looking into I2C bootloaders for an ATTINY coprocessor on a board I'm developing, and I ran into a bit of a snag. I have the need to detect what board the main processor's code is running on,...
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4 votes
3 answers
5k views

Spiffs vs Eeprom on esp8266

In my project, i have some data to save permanently. After some research i got many examples and informations to do that with eeprom. I used it effectively. After all i decide to deep dive to esp8266 ...
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0 votes
1 answer
654 views

make EEPROM.h use custom eeprom partition

I created the below partition table for an esp32 and replaced the 'default_8MB.csv' with it. # Name, Type, SubType, Offset, Size, Flags nvs, data, nvs, 0x9000, 0x5000, otadata, data, ...
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0 votes
2 answers
155 views

How can I save my float 'ave' on the EEPROM continuously?

How can I save my output continuously to EEPROM? Or is this even possible? Please help me out. void setup() { Serial.begin(9600); } void loop() { static unsigned long count = 0; static float ...
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0 votes
2 answers
108 views

EEPROM page rotates while writing to it

The following code intends to read from serial port and write the data byte by byte to a 24LC01B EEPROM. // 24LC01B PINS // Pin 1, A0: float // Pin 2, A1: float // Pin 3, A2: float // Pin 4, VSS: GND ...
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  • 153
0 votes
1 answer
94 views

Initalizing library object in own library

EDIT: @Juraj fixed the Issue, changes at the end of the post I am developing an application to program OneWire ID Chips. I am using the OneWire library (https://github.com/PaulStoffregen/OneWire) and ...
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1 vote
0 answers
266 views

Stuck in a loop when reading from EEPROM, works if I clear it first

EDIT: The problem was caused by storing a pointer in the EEPROM. Thanks to @KIIV for helping out Sorry for the enormous of wall of text, I'm trying to pare it down a bit. I have two Arduino Megas ...
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0 votes
1 answer
225 views

Esp32: upload eeprom file

I'd like to flash the eeprom sector with content so that the eeprom already holds data when it boots the first time. How do I upload such an eeprom file like I would do with avrdude on an atmega? Is ...
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  • 1,789
2 votes
2 answers
702 views

EEPROM.get returns bad data

I am using the attached code. What I am trying to do is: Test if there is a personalized "board serial number" written in the EEPROM (by previous code run) If data found was not 7 characters (e.g SN-...
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  • 242
0 votes
1 answer
208 views

Can you use an Arduino UNO as an EEPROM programmer

Hi I have an Arduino UNO and a AT28c64B and a single shift register, is it possible to make an EEPROM programmer with it? I’m not too good with the Arduino to do a lot of trial and error... I would ...
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2 votes
1 answer
149 views

EEPROM: managing address mapping between firmware versions

Is there a common way to handle changes in the mapping between eeprom addresses and variables between firmware versions? It's not about the eeprom memory to survive the update, but to be(come) ...
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  • 1,789
0 votes
2 answers
1k views

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 ...
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  • 790