# Storage **URL:** https://forum.arduino.cc/c/other-hardware/storage/58.md [Latest](https://forum.arduino.cc/latest.md) · [Categories](https://forum.arduino.cc/categories.md) --- ## [About the Storage category](https://forum.arduino.cc/t/about-the-storage-category/847498)
**Author:** [@system](https://forum.arduino.cc/u/system)\ **Replies:** 0\ **Last updated:** [April 12, 2021, 12:19pm UTC](https://forum.arduino.cc/t/about-the-storage-category/847498 "2021-04-12T12:19:29Z")
Using Arduino to interface SD cards, floppy drives, hard drives, EEPROMs, etc --- ## [How to get the best out of this forum](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/681320)
**Author:** [@PerryBebbington](https://forum.arduino.cc/u/PerryBebbington)\ **Replies:** 0\ **Last updated:** [November 4, 2020, 9:07am UTC](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/681320 "2020-11-04T09:07:17Z")
Welcome to the Arduino forum! A guide explaining how to get the best out of this forum is available at the link below. Please read it: --- ## [Don't Format SD cards with OS utilities!](https://forum.arduino.cc/t/dont-format-sd-cards-with-os-utilities/222016)
**Author:** [@fat16lib](https://forum.arduino.cc/u/fat16lib)\ **Replies:** 46\ **Last updated:** [April 15, 2021, 2:17pm UTC](https://forum.arduino.cc/t/dont-format-sd-cards-with-os-utilities/222016 "2021-04-15T14:17:15Z")
Always format SD cards using SD Formatter SD Memory Card Formatter for Windows/Mac | SD Association. NEVER format SD card with OS utilities! Here are some examples that show what can happen. First is an extreme case fo… --- ## [Waveshare ESP32-S3-ETH-8DI-8RO MCU - good way to get 5V for sensor power?](https://forum.arduino.cc/t/waveshare-esp32-s3-eth-8di-8ro-mcu-good-way-to-get-5v-for-sensor-power/1463527)
**Author:** [@woodmanexp](https://forum.arduino.cc/u/woodmanexp)\ **Replies:** 10\ **Last updated:** [October 14, 2026, 7:43pm UTC](https://forum.arduino.cc/t/waveshare-esp32-s3-eth-8di-8ro-mcu-good-way-to-get-5v-for-sensor-power/1463527 "2026-10-14T19:43:39Z")
Hi, Have been experimenting with Waveshare’s ESP32-S3-ETH-8DI-8RO module as a more physically robust alternative to their ESP32S3-POE-ETH module. (Programming of the two modules via Arduino IDE is similar) On the ESP32… --- ## [SD card not initializing on arduino Mega 2560(clone)](https://forum.arduino.cc/t/sd-card-not-initializing-on-arduino-mega-2560-clone/1455194)
**Author:** [@riothemaster](https://forum.arduino.cc/u/riothemaster)\ **Replies:** 25\ **Last updated:** [October 12, 2026, 12:10pm UTC](https://forum.arduino.cc/t/sd-card-not-initializing-on-arduino-mega-2560-clone/1455194 "2026-10-12T12:10:24Z")
Hello everyone, I am working on a automatic plant watering system using the Az-Mega 2560(the official one was out of stock :/ sooo....), a waterpump, a 9V battery, a buzzer, a relay and a Azdelivery SPI communication mi… --- ## [Using USB Flash Drive as storage on Arduino Uno Q via USB Hub](https://forum.arduino.cc/t/using-usb-flash-drive-as-storage-on-arduino-uno-q-via-usb-hub/1461197)
**Author:** [@the37signals1](https://forum.arduino.cc/u/the37signals1)\ **Replies:** 3\ **Last updated:** [October 2, 2026, 9:16am UTC](https://forum.arduino.cc/t/using-usb-flash-drive-as-storage-on-arduino-uno-q-via-usb-hub/1461197 "2026-10-02T09:16:50Z")
I've been trying to have this Arduino Uno Q recognize this flash drive on a USB hub so I can use it to store data created from other programs on the Arduino. I'm basically an amateur on this, but I'm super excited to lea… --- ## [Writing data to USB Stick with Shield and UNO](https://forum.arduino.cc/t/writing-data-to-usb-stick-with-shield-and-uno/1459185)
**Author:** [@alodium](https://forum.arduino.cc/u/alodium)\ **Replies:** 34\ **Last updated:** [September 30, 2026, 8:17am UTC](https://forum.arduino.cc/t/writing-data-to-usb-stick-with-shield-and-uno/1459185 "2026-09-30T08:17:40Z")
I have installed the USB Host Shield Library 2.0 (Version 1.7.0 - See attchments) I have a Shield mounted on my UNO R3 board and can run a small program, which displays the message "USB Host Shield Initialized". No… --- ## [Floppy Disk Emulation with an SD Card](https://forum.arduino.cc/t/floppy-disk-emulation-with-an-sd-card/1460232)
**Author:** [@grahamprie](https://forum.arduino.cc/u/grahamprie)\ **Replies:** 3\ **Last updated:** [September 21, 2026, 1:02pm UTC](https://forum.arduino.cc/t/floppy-disk-emulation-with-an-sd-card/1460232 "2026-09-21T13:02:17Z")
I want to use a MEGA 2560 with an SD Card to emulate a floppy disc drive on my Organ for storage of MIDI Files. The Organ uses 3.5" floppies formatted to the usual computer standard and the floppy drive is now unreliabl… --- ## [SD card(s) not initialising](https://forum.arduino.cc/t/sd-card-s-not-initialising/1455999)
**Author:** [@anon57936601](https://forum.arduino.cc/u/anon57936601)\ **Replies:** 67\ **Last updated:** [August 25, 2026, 8:31pm UTC](https://forum.arduino.cc/t/sd-card-s-not-initialising/1455999 "2026-08-25T20:31:58Z")
I'm trying to use SD cards both via a generic SD card breakout board and an Adafruit touchscreen with built in SD card slot. So far, CardInfo.ino, SdFormatter.ino and SdInfo are all failing to recognise the cards. I've… --- ## [Termination of SD\_Card with resistor](https://forum.arduino.cc/t/termination-of-sd-card-with-resistor/1455784)
**Author:** [@zeeshanhaider](https://forum.arduino.cc/u/zeeshanhaider)\ **Replies:** 7\ **Last updated:** [August 14, 2026, 4:04pm UTC](https://forum.arduino.cc/t/termination-of-sd-card-with-resistor/1455784 "2026-08-14T16:04:31Z")
I am facing the issue of termination on my custom PCB deisgn for the SD\_Card when I remove the SD\_Card the other slave DW1000 starts giving results weirdly but when the SDCard is present it gives me correct results. I am… --- ## [Best way to optimize Arduino sensor data logging without losing readings?](https://forum.arduino.cc/t/best-way-to-optimize-arduino-sensor-data-logging-without-losing-readings/1452859)
**Author:** [@techy247](https://forum.arduino.cc/u/techy247)\ **Replies:** 19\ **Last updated:** [August 12, 2026, 10:15am UTC](https://forum.arduino.cc/t/best-way-to-optimize-arduino-sensor-data-logging-without-losing-readings/1452859 "2026-08-12T10:15:09Z")
I'm working on an Arduino project that reads data from multiple sensors and stores the values on an SD card for later analysis. As the number of sensors increases, I've noticed occasional missed readings and delays in lo… --- ## [SD File problem](https://forum.arduino.cc/t/sd-file-problem/1449425)
**Author:** [@rog\_d](https://forum.arduino.cc/u/rog_d)\ **Replies:** 21\ **Last updated:** [June 24, 2026, 2:50pm UTC](https://forum.arduino.cc/t/sd-file-problem/1449425 "2026-06-24T14:50:39Z")
Hi All, Help with a little problem please as I'm quite new to Arduino. I have connected to my Arduino R4 an SD card read/writer. On the micro SD card I have two text files:- MUSIC1.TXT and MUSIC2.TXT. One has 13 entrie… --- ## [Waveshare ESP32-P4-ETH and SD card interface](https://forum.arduino.cc/t/waveshare-esp32-p4-eth-and-sd-card-interface/1448913)
**Author:** [@chrissaich](https://forum.arduino.cc/u/chrissaich)\ **Replies:** 3\ **Last updated:** [June 24, 2026, 12:15pm UTC](https://forum.arduino.cc/t/waveshare-esp32-p4-eth-and-sd-card-interface/1448913 "2026-06-24T12:15:43Z")
I am developing a project using the Waveshare ESP32-P4-ETH board and need to use the SD Card. I have tried the standard SD and SDMMC libraries with all suggested combinations of IO pins for the interface, but all I get i… --- ## [ESP32 Data Logger Occasionally Misses SD Card Writes After Several Hours of Operation](https://forum.arduino.cc/t/esp32-data-logger-occasionally-misses-sd-card-writes-after-several-hours-of-operation/1448729)
**Author:** [@maria1719](https://forum.arduino.cc/u/maria1719)\ **Replies:** 25\ **Last updated:** [June 21, 2026, 3:03pm UTC](https://forum.arduino.cc/t/esp32-data-logger-occasionally-misses-sd-card-writes-after-several-hours-of-operation/1448729 "2026-06-21T15:03:43Z")
Hi everyone, I'm working on an ESP32-based environmental monitoring system that collects temperature, humidity, and air quality data and stores the readings on a microSD card every few minutes. The system works well in… --- ## [ESP32-S3 + blue microSD module: MISO stuck LOW when idle, SD.begin() fails](https://forum.arduino.cc/t/esp32-s3-blue-microsd-module-miso-stuck-low-when-idle-sd-begin-fails/1441287)
**Author:** [@sedatbaturaydin](https://forum.arduino.cc/u/sedatbaturaydin)\ **Replies:** 2\ **Last updated:** [April 23, 2026, 9:45pm UTC](https://forum.arduino.cc/t/esp32-s3-blue-microsd-module-miso-stuck-low-when-idle-sd-begin-fails/1441287 "2026-04-23T21:45:35Z")
Hi all, stuck on mounting a microSD card and looking for a sanity check before I replace the module. Hardware ESP32-S3-DevKitC-1 (powered over USB-C, 5V pin used for module VCC) Generic blue microSD breakout (AMS1117 … --- ## [Want to create a diagram of data from a sensor and save/update it permantly on a SD Card](https://forum.arduino.cc/t/want-to-create-a-diagram-of-data-from-a-sensor-and-save-update-it-permantly-on-a-sd-card/1431746)
**Author:** [@silentik](https://forum.arduino.cc/u/silentik)\ **Replies:** 11\ **Last updated:** [April 14, 2026, 6:04am UTC](https://forum.arduino.cc/t/want-to-create-a-diagram-of-data-from-a-sensor-and-save-update-it-permantly-on-a-sd-card/1431746 "2026-04-14T06:04:08Z")
In this project, I plan to use an Arduino to read data from a sensor and store it on an SD card. The system should work completely autonomously, without being connected to a computer. The Arduino will continuously collec… --- ## [How can I safe data from various sources using an Arduino Mega to a NAS, (Using MQTT)?](https://forum.arduino.cc/t/how-can-i-safe-data-from-various-sources-using-an-arduino-mega-to-a-nas-using-mqtt/1438713)
**Author:** [@FTMZ](https://forum.arduino.cc/u/FTMZ)\ **Replies:** 31\ **Last updated:** [April 12, 2026, 7:45pm UTC](https://forum.arduino.cc/t/how-can-i-safe-data-from-various-sources-using-an-arduino-mega-to-a-nas-using-mqtt/1438713 "2026-04-12T19:45:27Z")
Hi People, I recently managed to get my W5500 working on my Arduino Mega, with the purpose of storing various data, like (mainly) temperatures along with time stamps. I’m having a hard time getting the data saved onto … --- ## [FRAM Memory Question (MB85RC256V)](https://forum.arduino.cc/t/fram-memory-question-mb85rc256v/1434405)
**Author:** [@JohnRob](https://forum.arduino.cc/u/JohnRob)\ **Replies:** 18\ **Last updated:** [March 16, 2026, 12:45am UTC](https://forum.arduino.cc/t/fram-memory-question-mb85rc256v/1434405 "2026-03-16T00:45:38Z")
I understand the MB85 is structured to be a linear 32k bytes. And with the FRAM\_I2C I can write multibyte values. So if I write a int8\_t then an uint16\_t then 4 more int8\_t values. Then its up to my program to “r… --- ## [Sdcard issue when using the Arduino examples](https://forum.arduino.cc/t/sdcard-issue-when-using-the-arduino-examples/1431984)
**Author:** [@Cor2](https://forum.arduino.cc/u/Cor2)\ **Replies:** 11\ **Last updated:** [February 22, 2026, 9:05am UTC](https://forum.arduino.cc/t/sdcard-issue-when-using-the-arduino-examples/1431984 "2026-02-22T09:05:07Z")
Hello, With Windows10 I have formatted an 32 Gb SDcard as FAT32 and checked by asking the properties after the format was complete. It was OK. After executing example CardInfo with a SDcard module and an Arduino Nano … --- ## [Sdfat : A different approach to SD card ejection handling with sdfat](https://forum.arduino.cc/t/sdfat-a-different-approach-to-sd-card-ejection-handling-with-sdfat/1432109)
**Author:** [@Baxsie](https://forum.arduino.cc/u/Baxsie)\ **Replies:** 3\ **Last updated:** [February 22, 2026, 8:56am UTC](https://forum.arduino.cc/t/sdfat-a-different-approach-to-sd-card-ejection-handling-with-sdfat/1432109 "2026-02-22T08:56:28Z")
I am doing a project using an Adafruit AdaLogger rp2040 Feather. I am using the normal sdfat stuff that was included in the package for the board: I was struggling with handling the normal expected (no files open) e… --- ## ["Read Write" Example writes twice](https://forum.arduino.cc/t/read-write-example-writes-twice/1429609)
**Author:** [@kooner](https://forum.arduino.cc/u/kooner)\ **Replies:** 10\ **Last updated:** [February 12, 2026, 4:18am UTC](https://forum.arduino.cc/t/read-write-example-writes-twice/1429609 "2026-02-12T04:18:03Z")
Hello, I purchased a P254 MicroSD card from Adafruit and got it working with my UNO R3. I ran the Card Info example and it worked. However, when I tried the Read Write example the “testing 1,2,3.” text was written twi… --- ## [When ESP32S3 is writing data to SD card, how to remove the card safely?](https://forum.arduino.cc/t/when-esp32s3-is-writing-data-to-sd-card-how-to-remove-the-card-safely/1428679)
**Author:** [@bbqq](https://forum.arduino.cc/u/bbqq)\ **Replies:** 11\ **Last updated:** [February 3, 2026, 10:02am UTC](https://forum.arduino.cc/t/when-esp32s3-is-writing-data-to-sd-card-how-to-remove-the-card-safely/1428679 "2026-02-03T10:02:33Z")
Hello, I am writing a program to find out how fast data is being written to a SD card. If I remove all unnecessary statements (such as a if-statment to check if certain number of lines has reached), how do I savely close… --- ## [Lecture micro sd 5v](https://forum.arduino.cc/t/lecture-micro-sd-5v/1425418)
**Author:** [@novice\_g](https://forum.arduino.cc/u/novice_g)\ **Replies:** 10\ **Last updated:** [January 19, 2026, 3:12pm UTC](https://forum.arduino.cc/t/lecture-micro-sd-5v/1425418 "2026-01-19T15:12:08Z")
Hello fellow electronics experts, I'm having a problem with my 5V micro SD card reader, which I'm connecting to my ESP32 Devkit board. I'm using 21cm jumper wires and the following pins: GPIO4—CS GPIO18—SCK GPIO19—MIS… --- ## [How to 'trim an SD file](https://forum.arduino.cc/t/how-to-trim-an-sd-file/1423357)
**Author:** [@Deva\_Rishi](https://forum.arduino.cc/u/Deva_Rishi)\ **Replies:** 7\ **Last updated:** [January 6, 2026, 1:39pm UTC](https://forum.arduino.cc/t/how-to-trim-an-sd-file/1423357 "2026-01-06T13:39:45Z")
Hi, I am encountering situations where a fairly large file on an SD card which contains many (RGB pixel) frames, and for a reason that i think i have identified and corrected, sometimes the last frame is not written com… --- ## [Optimised setup for saving to SD, using large buffer, low current, low risk of corruption etc](https://forum.arduino.cc/t/optimised-setup-for-saving-to-sd-using-large-buffer-low-current-low-risk-of-corruption-etc/1414905)
**Author:** [@pete73](https://forum.arduino.cc/u/pete73)\ **Replies:** 28\ **Last updated:** [November 19, 2025, 4:23pm UTC](https://forum.arduino.cc/t/optimised-setup-for-saving-to-sd-using-large-buffer-low-current-low-risk-of-corruption-etc/1414905 "2025-11-19T16:23:13Z")
A bit difficult to write the description there. I want to log at extremely low battery power about 250 bytes per second but using an nRF52840 which has 256k ram, so I am assuming I should have at least 128k available to… --- ## [CH376S - Mega2560 Connectivity Issues](https://forum.arduino.cc/t/ch376s-mega2560-connectivity-issues/1412793)
**Author:** [@chronoxay](https://forum.arduino.cc/u/chronoxay)\ **Replies:** 8\ **Last updated:** [November 13, 2025, 5:47am UTC](https://forum.arduino.cc/t/ch376s-mega2560-connectivity-issues/1412793 "2025-11-13T05:47:18Z")
I am trying to get a CH376S module communicating with my Elegoo Mega2560 using 4-wire SPI, and am having a lot of trouble here. Here’s my current wiring: \[Any pins not mentioned have been left disconnected.\] (M) Mega2… --- ## [SD card initialization fails on custom PCB](https://forum.arduino.cc/t/sd-card-initialization-fails-on-custom-pcb/1410867)
**Author:** [@roby\_02](https://forum.arduino.cc/u/roby_02)\ **Replies:** 60\ **Last updated:** [November 7, 2025, 8:17pm UTC](https://forum.arduino.cc/t/sd-card-initialization-fails-on-custom-pcb/1410867 "2025-11-07T20:17:34Z")
I designed my own PCB with a built-in SD card reader, but I'm having trouble reading the SD card. I can’t figure out what’s causing the issue. Could someone help me identify the problem? I bought this module on AliExpr… --- ## [Can't get \>64MB SD card working on ESP32 Sd.h](https://forum.arduino.cc/t/cant-get-64mb-sd-card-working-on-esp32-sd-h/1411056)
**Author:** [@embed44](https://forum.arduino.cc/u/embed44)\ **Replies:** 0\ **Last updated:** [October 29, 2025, 11:16am UTC](https://forum.arduino.cc/t/cant-get-64mb-sd-card-working-on-esp32-sd-h/1411056 "2025-10-29T11:16:29Z")
I am using a very simple set up with ESP-32S3 dev kit and an SD card. Using Sd.h. I couldn't get any 16GB or 32GB SD card to mount, but by chance I had a old 64MB (yes really) card and it worked. Tried formatting the S… --- ## [How to Upload Large .h Image Files to External SPI Flash (W25Q64) on ESP32?](https://forum.arduino.cc/t/how-to-upload-large-h-image-files-to-external-spi-flash-w25q64-on-esp32/1410067)
**Author:** [@Mars-Sojourner](https://forum.arduino.cc/u/Mars-Sojourner)\ **Replies:** 6\ **Last updated:** [October 22, 2025, 1:26am UTC](https://forum.arduino.cc/t/how-to-upload-large-h-image-files-to-external-spi-flash-w25q64-on-esp32/1410067 "2025-10-22T01:26:03Z")
Hi all, I have a Freenove ESP32 Board: dual-core 32-bit microprocessor, up to 240 MHz, 4 MB Flash, 520 KB SRAM. I ran this display related sketch on it and it ran fine: #include \ #include \ #include "… --- ## [SD Card Reader with buffer](https://forum.arduino.cc/t/sd-card-reader-with-buffer/1409425)
**Author:** [@kooner](https://forum.arduino.cc/u/kooner)\ **Replies:** 12\ **Last updated:** [October 19, 2025, 2:11pm UTC](https://forum.arduino.cc/t/sd-card-reader-with-buffer/1409425 "2025-10-19T14:11:05Z")
Hello, I have an Arduino Uno R3 and was wondering if someone could recommend a simple SD card reader? I’ve read a few posts about some SD card readers that do not release the MISO line which will cause issues with other… [Next page](https://forum.arduino.cc/c/other-hardware/storage/58.md?page=1)