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Micro SD Memory Card Reader Writer Module with SPI Interface for Arduino

This Micro SD TF (TransFlash) card reader and writer module adds removable file storage to your Arduino or other microcontroller projects. It includes an onboard 3.3V voltage regulator and level shifters, making it safe to connect directly to both 5V and 3.3V microcontrollers. The module communicates over the standard SPI bus and works with the built-in Arduino SD library -- no extra libraries needed.

⚠️ Important: SD cards must be formatted as FAT16 or FAT32 before use. exFAT and NTFS are not supported. SDXC cards (64 GB and larger) are not compatible. For best results, use name-brand cards 32 GB or smaller.

🔧 How It Works

Your microcontroller sends commands and data to the SD card over the SPI bus using four signal lines: MOSI (data out), MISO (data in), SCK (clock), and CS (chip select).
The onboard AMS1117-3.3V (or equivalent) voltage regulator converts the 5V input down to the 3.3V required by the SD card.
The onboard 74LVC125A (or equivalent) level-shifting IC translates 5V logic signals to 3.3V-safe levels for the SD card's data lines.
The Arduino SD library handles the FAT16/FAT32 file system, allowing you to create, read, write, and delete files and directories.

⚡ Key Features

Wide Card Support -- Works with Micro SD (up to 2 GB) and Micro SDHC (up to 32 GB) cards
Onboard 3.3V Regulator -- No external voltage regulator needed; just connect 5V and go
Built-in Level Shifters -- Safely interfaces with both 5V and 3.3V logic microcontrollers
Standard SPI Interface -- Uses MOSI, MISO, SCK, and CS for fast, reliable communication
Arduino SD Library Compatible -- Works with the built-in Arduino SD library right out of the box
Breadboard Friendly -- 6-pin male right-angle header on 2.54mm centers plugs directly into a breadboard
Mounting Holes -- 4 × M2 holes (2.2mm diameter) for secure project installation
LED Power Indicator -- Confirms the module is receiving power

📐 Specifications

Operating Voltage (VCC)	4.5V – 5.5V DC
Logic Level	3.3V and 5V compatible (onboard level shifters)
Communication Interface	SPI (Serial Peripheral Interface)
Supported Card Types	Micro SD (up to 2 GB), Micro SDHC (up to 32 GB)
Supported File Systems	FAT16, FAT32
Onboard Regulator	AMS1117-3.3V or equivalent LDO
Level Shifter	74LVC125A or equivalent
Header Pins	6-pin male right-angle, 2.54mm pitch
Mounting Holes	4 × M2 (2.2mm diameter)
Board Dimensions	Approx. 42 × 24 mm (1.65 × 0.94 inches) L × W
Operating Current	~80 mA (read/write), ~100 µA (idle)

📌 Pin Description

The module has a 6-pin male right-angle header on 2.54mm centers. It can be inserted directly into a breadboard, or female Dupont-style jumper wires can be used for connections.

Pin	Label	Description
1	GND	Ground -- must share common ground with your microcontroller
2	VCC	Power input: 4.5V – 5.5V DC
3	MISO	SPI Master In, Slave Out -- data from SD card to microcontroller
4	MOSI	SPI Master Out, Slave In -- data from microcontroller to SD card
5	SCK	SPI Clock -- clock signal from microcontroller
6	CS	SPI Chip Select -- active LOW to select this device

Note: Some versions of this module have a silkscreen error where MISO is labeled as "MOSO." The pin still functions as MISO.

🔌 Wiring to Arduino Uno

Module Pin	Arduino Uno Pin
VCC	5V
GND	GND
MISO	Pin 12 (MISO)
MOSI	Pin 11 (MOSI)
SCK	Pin 13 (SCK)
CS	Pin 10 (SS)

💡 Tip: The CS pin can be connected to any available digital pin -- just update the pin number in your Arduino code. Pin 10 is the default used by the Arduino SD library. The MOSI, MISO, and SCK pins are fixed hardware SPI pins on the Uno/Nano and cannot be changed.

📦 What's in the Box

1x Micro SD Memory Card Reader/Writer Module with SPI Interface

Micro SD card, jumper wires, and Arduino board are not included.

🛒 What You'll Need

Arduino Uno, Nano, or compatible board -- or any microcontroller with SPI support
Micro SD or Micro SDHC card -- 32 GB or smaller, formatted as FAT32
Jumper wires -- female-to-male Dupont wires or a breadboard
USB cable -- to connect your Arduino to your computer for programming

🔌 Compatible With

Arduino Uno, Nano, Mega, Leonardo, and other Arduino-compatible boards
ESP32 and ESP8266 development boards
STM32 microcontrollers
Raspberry Pi Pico
Any microcontroller with SPI support and 3.3V or 5V logic

🎯 Typical Applications

Sensor data logging (temperature, humidity, pressure, GPS coordinates)
Storing configuration files for microcontroller projects
Audio WAV file playback
Image storage for TFT display projects
GPS track logging
Flight data recorders for drones and RC aircraft
Portable measurement and test instruments
Storing web pages for Arduino-based web servers

⚠️ Important Notes

Format your SD card as FAT16 or FAT32 before use. exFAT and NTFS are not supported by the Arduino SD library.
SDXC cards (64 GB and larger) are not supported.
The Arduino SD library supports filenames in 8.3 format only (e.g., DATALOG.CSV). Filenames must be 8 characters or fewer with a 3-character extension.
Always close files after writing to prevent data loss.
Do not remove the SD card while the Arduino is actively reading or writing -- this can corrupt the file system.
The module draws approximately 80 mA during active read/write operations. Ensure your power supply can handle the total current draw if powering multiple modules.
For best reliability, use name-brand SD cards (SanDisk, Samsung, Kingston) in the 4 GB – 16 GB range.

🏪 About Envistia Mall

Envistia Mall is a US-based electronics retailer specializing in development boards, sensors, modules, and components for makers, engineers, and educators. We ship from the United States with fast handling times. Product documentation and technical support are available at our dedicated support site.

📦 Fast Free US Shipping | 🔄 Hassle-Free Returns | 📧 Responsive Customer Support

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