Micro SD TF Memory Card Reader Writer Module with SPI Interface For Arduino

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 with no extra libraries needed.

How It Works

1. 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).
2. The onboard voltage regulator converts the 5V input down to the 3.3V required by the SD card, protecting it from overvoltage.
3. The onboard level-shifting IC translates 5V logic signals to 3.3V-safe levels for the SD card data lines.
4. The Arduino SD library handles the FAT16 or FAT32 file system, allowing you to create, read, write, and delete files and directories.

Specifications

• Operating Voltage (VCC): 4.5V to 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 2GB), Micro SDHC (up to 32GB)
• 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 x M2 (2.2mm diameter)
• Board Dimensions: Approx. 42 x 24 mm (1.65 x 0.94 inches) L x W
• Operating Current: Approximately 80 mA (read/write), approximately 100 uA (idle)

Pin Description

• GND: Ground. Must share common ground with your microcontroller.
• VCC: Power input, 4.5V to 5.5V DC.
• MISO: SPI Master In, Slave Out. Data from SD card to microcontroller.
• MOSI: SPI Master Out, Slave In. Data from microcontroller to SD card.
• SCK: SPI Clock. Clock signal from microcontroller.
• CS: SPI Chip Select. Active LOW to select this device on the SPI bus.

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

• VCC to Arduino 5V
• GND to Arduino GND
• MISO to Arduino Pin 12
• MOSI to Arduino Pin 11
• SCK to Arduino Pin 13
• CS to Arduino Pin 10

The CS pin can be connected to any available digital pin. Update the pin number in your Arduino code to match. Pin 10 is the default used by the Arduino SD library.

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.

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

Important Notes

• Format your SD card as FAT16 or FAT32 before use. exFAT and NTFS are not supported.
• SDXC cards (64GB and larger) are not supported.
• The Arduino SD library supports filenames in 8.3 format only (for example, DATALOG.CSV).
• Always close files after writing to prevent data loss.
• Do not remove the SD card while the Arduino is actively reading or writing.
• For best reliability, use name-brand SD cards (SanDisk, Samsung, Kingston) in the 4GB to 16GB range.