Communication interface is a standard SPI interface
Power supply is 4.5V ~ 5.5V, 3.3V voltage regulator circuit board
Micro SD card into the direction of signals into 3.3V, microSD card toward the direction of the control interface MISO signal is also converted to 3.3V, general AVR microcontroller system can read the signal
A total of six pins (GND, VCC, MISO, MOSI, SCK, CS), GND to ground, VCC is the power supply, MISO, MOSI, SCK is SPI bus, CS is the chip select signal pin