Overview of the SD/MicroSD breakout board: Allows the use of SD cards with microcontrollers. Supports SDIO protocol for higher transmission speed than traditional SPI. SDIO enables multi-pin data protocol (up to 4 data pins simultaneously) and higher clock speeds. Compatible only with microcontrollers that use 3V power and logic. Can also be used in SPI mode, but does not include level converters for use with 5V microcontrollers. Verification of SDIO support and corresponding firmware/libraries of the microcontroller is necessary. Micro SD card is not included.