DEV-12761 Datasheet PDF - SparkFun Electronics

Description:
   Running out of memory space in your Arduino project? The SparkFun microSD Shield equips your Arduino with mass-storage capability, so you can use it for data-logging or other related projects.
   Communication with microSD cards is achieved over an SPI interface. The SCK, DI, and DO pins of the microSD socket are broken out to the ATmega168/328’s standard SPI pins (digital 11-13), while the CS pin is broken out to Arduino’s D8 pin. If you decide to use one of the many open source FAT libraries (like FAT16 or SDFat) make sure to change the code to reflect the location of the CS pin.