Adafruit Micro SD SPI or SDIO Card Breakout Board - 3V ONLY!

Micro SD cards are a perfect match for microcontrollers, offering an affordable, durable, and easy-to-find storage solution for a wide variety of applications like images, fonts, GIFs, audio files, or sensor logs. With an SD card, you can quickly store and retrieve data using a common SD card reader on any computer.

For beginner projects, setting up an SD card with an SPI-to-SD breakout board is simple—just wire it to an SPI port and a chip select pin, and you're ready to start reading and writing files. However, as your project grows and requires faster data transfer speeds, you may find SPI limitations slow down your workflow, as it only uses one data pin.

This breakout board offers a solution by supporting SDIO (Secure Digital Input Output), a multi-pin data protocol that allows for faster data transfer by using up to four data pins simultaneously. SDIO is typically faster than SPI, making it ideal for projects that require high-speed file access. For instance, when we used SDIO with the SAMD51 Grand Central on CircuitPython, we saw a speed increase of approximately double compared to SPI.

Before using SDIO, ensure that your microcontroller has SDIO support and that you have the necessary firmware or library. SDIO is usually available on higher-end microcontrollers and may require a specific pin set. This board can also be used in SPI mode, but it doesn't include level shifters, so it's designed for use with 3V power and logic microcontrollers only. It cannot be used with 5V microcontrollers due to the lack of level shifting or power regulation.

The breakout comes with a header for easy breadboard use, but please note that the micro SD card itself is not included.

Technical Details:

• Product Dimensions: 25.4mm x 22.8mm x 3.5mm (1.0" x 0.9" x 0.1")
• Product Weight: 2.5g (0.1oz)
• Revision History: Updated as of April 12, 2024, with Adafruit Pinguin for clearer silkscreen design.