SD Memory Card Reader Writer Module with SPI Interface for Arduino

SD Memory Card Reader Writer Module with SPI Interface for Arduino

This SD Card SPI Read/Write Module lets you add removable file storage to your Arduino or other microcontroller projects using standard full-sized SD cards. It includes onboard level shifting and features separate 3.3V and 5V power input pins, making it compatible with a wide range of microcontrollers. The module works with the built-in Arduino SD library with no extra libraries needed.

Important: This module has separate 3.3V and 5V power input pins. Connect only one, either 3.3V or 5V, depending on your microcontroller. Connecting both simultaneously may damage the module.

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. When using the 5V pin, the onboard regulator steps the voltage down to the 3.3V required by the SD card. When using the 3.3V pin, power is supplied directly.
3. The onboard level-shifting circuitry translates logic signals between your microcontroller's voltage and the 3.3V levels required by the SD card.
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: 3.3V or 5V DC (separate input pins, use only one)
• Logic Level: 3.3V and 5V compatible (onboard level shifters)
• Communication Interface: SPI (Serial Peripheral Interface)
• Supported Card Types: SD (up to 2GB), SDHC (up to 32GB), full-sized cards
• Supported File Systems: FAT16, FAT32
• Card Slot Type: Spring-loaded push-push
• Header Pins: 9-pin (8 active + 1 NC), 2.54mm pitch
• Board Dimensions: Approx. 46 x 30 mm (1.81 x 1.18 inches) L x W
• Indicators: Power LED, Activity LED

Pin Description

• GND: Ground. Must share common ground with your microcontroller.
• 3.3V: 3.3V power input. Use if your microcontroller operates at 3.3V.
• 5V: 5V power input. Use if your microcontroller operates at 5V.
• CS: SPI Chip Select. Active LOW to select this device on the SPI bus.
• MOSI: SPI Master Out, Slave In. Data from microcontroller to SD card.
• SCK: SPI Clock. Clock signal from microcontroller.
• MISO: SPI Master In, Slave Out. Data from SD card to microcontroller.

Wiring to Arduino Uno (5V)

• 5V 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. When using a 3.3V microcontroller like the ESP32, connect the 3.3V pin instead of 5V.

What's in the Box

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

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

Compatible With

• Arduino Uno, Nano, Mega, Leonardo, and other Arduino-compatible boards (5V)
• ESP32 and ESP8266 development boards (3.3V)
• STM32 microcontrollers (3.3V)
• Raspberry Pi Pico (3.3V)
• AVR, ARM, and PIC microcontrollers with SPI support

Important Notes

• Connect only one power pin, either 3.3V or 5V. Connecting both may damage the module.
• 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.
• Full-sized SD cards have a physical write-protect switch on the side. Ensure it is unlocked before writing.
• For best reliability, use name-brand SD cards (SanDisk, Samsung, Kingston) in the 4GB to 16GB range.