The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →You can simulate an SD card with an Arduino in Wokwi without a physical card or reader. Add the microSD component, wire its SPI pins to the Uno, and use an SD library to read files. To use your own files, provide them through the browser editor’s SD Card tab or—when working in VS Code or the CLI—an SD-card folder or image.
What Wokwi simulates
Wokwi’s microSD component uses SPI and creates a FAT16 filesystem when simulation starts. Its reference describes an 8 MB default capacity and says project files are copied onto the simulated card by default. The component exposes CD, DO, GND, SCK, VCC, DI, and CS pins; CD is always disconnected in the simulator because a card is treated as present.
These are simulator details, not a guarantee that every physical card, reader, filesystem, capacity, or electrical setup will work the same way. For real hardware, check the module’s voltage and wiring requirements for your board.
Add the microSD component and wire it to an Uno
In the Wokwi editor, add the microSD card component to the project, then connect its SPI signals to the Uno as follows. The Uno reference identifies the corresponding SPI pins.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstall#1 Best Overall
- Compatible with Arduino UNO, R3, MEGA 2560 Due: The HiLetgo 5pcs Micro SD TF Card Adapter Reader Module works with these Arduino boards for easy data transfer.
- 6-pin SPI interface: The module features a 6-pin SPI interface for connecting to micro SD cards and reading data.
- Chip level conversion: The module converts chip level data into a standard format for easy access and analysis.
- Lightweight and compact: Weighing just 0.11 pounds, the module is lightweight and compact for easy handling.
| microSD pin | Arduino Uno pin | Signal |
|---|---|---|
| SCK | 13 | SPI clock |
| DO | 12 | MISO (data from card) |
| DI | 11 | MOSI (data to card) |
| CS | 10 | Chip select |
| VCC | 5V | Power |
| GND | GND | Ground |
Wokwi documents the SPI pin mapping and component behavior in its microSD card reference and Arduino Uno reference. The wiring above is for the simulated Uno setup; don’t assume a physical SD module can be wired identically without checking its requirements.
Initialize and inspect the simulated card
Wokwi’s microSD reference includes an SdFat example that sets chip select to pin 10 and SPI speed to 4 MHz, calls sd.begin, reports initialization or partition errors, and lists files with sd.ls(LS_R | LS_SIZE). Use that example when you want to confirm that the card initialized and see its directory contents. The reference also links examples for the built-in SD library and for displaying a bitmap stored on the card.
Rank #2
- Micro SD Card Module: The module includes 74HC125 and AMS1117 chips, enabling voltage level conversion between 3.3V and 5V systems, ensuring stable communication between the Micro SD card and host devices with different voltage levels.
- Interface level: 3.3V or 5V
- Supported Interface: SPI
- Supported Card Type: Micro SD Card (TF Card)
- Socket: Pop-up
SPI.h is available as a built-in Arduino library in Wokwi. Third-party libraries such as SdFat can be added through the editor’s Library Manager; a project can also request a particular version in libraries.txt by adding @version to the library entry. See Wokwi’s Arduino libraries guide.
Provide files to the simulated card
Browser editor
The microSD reference says the simulator copies project files to the card by default. It also documents uploading binary files through an SD Card tab for paying users. Browser-editor plan features can change, so check Wokwi’s current offering if that upload option matters to you.
Rank #3
- Micro SD Card Adapter Mini Board: Connects to various sensors and periodically stores collected data on an SD card
- Input Voltage: 3.3V
- Supported Interface: SPI
- Supported Card Type: Micro SD Card (TF Card)
- Socket: Pop-up
VS Code extension
For the documented VS Code setup, use Wokwi extension version 4.0.0 or newer. Create a folder named sdcard next to wokwi.toml; its contents are copied to the simulated card each time simulation starts. The documented alternative is a [[sdcard]] configuration that points to a folder or raw image and can specify a size and writeback = true. The configuration guide documents a maximum size of 256 MB.
Writeback is off by default. When enabled, card changes—including deletions—are mirrored back when the simulation stops or restarts. Files are read at simulation start, so restart after editing the source files. Full options are in Wokwi’s project configuration guide.
Rank #4
![Adafruit MicroSD Card Breakout Board+ [ADA254]](https://m.media-amazon.com/images/I/419rDaz-C7L._SL160_.jpg)
- Activity LED lights up when the SD card is being read or written
- Push-push socket with card slightly over the edge of the PCB so its easy to insert and remove
- Works great with Arduino, with tons of example code and wiring diagrams
- Skill Level: Component or Part
Wokwi CLI
The CLI documents SD-card configuration for version 0.28.0 or newer. Its flags include --sdcard, --sdcard-size, --sdcard-writeback, --sdcard-out, and --no-sdcard. The CLI documentation specifies a limit of up to 64 MB on the CI server; that is distinct from the 256 MB maximum stated in the VS Code configuration guide. Consult the CLI usage guide for flag behavior and configuration details.
Choose the workflow that fits your project
| Workflow | How files are supplied | Configuration and capacity | Persistence |
|---|---|---|---|
| Browser editor | Project files are copied by default; paying users can upload binary files through the SD Card tab. | Wokwi documents an 8 MB default simulated filesystem. | Not stated in the microSD reference. |
| VS Code extension | Put files in an sdcard folder next to wokwi.toml, or configure a folder or raw image. |
Version 4.0.0 or newer; configuration guide maximum is 256 MB. | Optional writeback mirrors changes and deletions when simulation stops or restarts. |
| CLI | Configure the card with the documented SD options or disable it with --no-sdcard. |
Version 0.28.0 or newer; up to 64 MB on the CI server. | Writeback and output are configurable with --sdcard-writeback and --sdcard-out. |
These figures describe different Wokwi contexts, not a single universal card-size limit. Wokwi says it is free for personal use; current plan details are available on its pricing page.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteBest Value
- ✹✹The module (Micro SD Card Adapter) is a Micro SD card reader module, through the file system and the SPI interface driver, SCM system to complete the file to read and write MicroSD card. for Arduino users can directly use the for Arduino IDE comes with an SD Card to complete the library card initialization and read-write.
- ✹✹The module built-in level regulator circuit, level conversion circuit board that can interface level is 5V or 3.3V.
- ✹✹Voltage: 4.5V~5.5V DC; Communication Interface: Standard SPI; Interface Voltage Level: 3.3V or 5V;
- ✹✹Applicable card type: Micro SD Card, Micro SDHC Card.
- ✹✹Micro SD card to signal the direction of converts 3.3V, Micro SD card interface to control the direction of the MISO signal is also converted to 3.3V, general AVR microcontroller systems can read the signal.；
Moving from simulation to a physical Arduino
You do not need to buy or connect a physical microSD card to run the Wokwi simulation. For a hardware follow-up, you will need an appropriate microSD card and a compatible SPI card module or breakout. Verify voltage compatibility, wiring, and library configuration for your specific board and module rather than treating Wokwi’s simplified component behavior as a hardware test.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
