The SparkFun Level Shifting microSD Breakout is quite similar to the SparkFun microSD Transflash Breakout, but with the included level shifting hardware, this board allows you to utilize a microSD card at Arduino’s SD library’s top speed on a 5V system. With this small breakout board, that is not much bigger than your fingernail, adding mass storage to your project will never be easier.
This breakout is also a bit unique in that it level translates all of its outputs back to the level of the hardware it’s connected to.
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