Micro SD Card Reader Module also called Micro SD Adaptor which is designed for dual I/O voltages. The Module is a simple solution for transferring data to and from a standard SD card. The pinout is directly compatible with Not only with Arduino as shown in the diagram in below, but can also be used with other microcontrollers. Micro SD Card Reader Module has an SPI interface which is compatible with any sd card and it uses 5V or 3.3V power supply which is compatible with Arduino UNO/Mega.SD module has various applications such as data logger, audio, video, graphics.

There are total of six pins (GND, VCC, MISO, MOSI, SCK, CS), GND to ground, VCC is the power supply, MISO, MOSI, SCK is the SPI bus, CS is the chip select signal pin; 3.3V regulator circuit: LDO regulator output 3.3V as level converter chip, Micro SD card supply.