We can find Micro SD card because only eight pins is less than a Vss SD card. Of course, you can also buy a condom card on the Micro SD card, so that the size of the SD card as big as it is and this time put the 9-pin card and SD card on the same, you can fully operate as SD card .
spi connecting the circuit is extremely simple, connect the power supply line Vdd and the ground line Vss, followed spi on the CS, SCLK, DI (MOSI), and DO (MISO) can be, other pins can be vented. Note that the SD card and the operating voltage of the power supply are 2.7-3.6V, 5V microcontroller to level conversion or series limiting resistor. Also remember CS SD card, SCLKh and DI use pull-up resistor of 10 ~ 100K. I set the socket of the circuit card, Micro SD card because the pins too close, poor welding, SD card relatively good solder pins. Because there is no deck, but there is no special soldered directly to the PCB I'll put on the card, eh expense of a card sets. Here is my own painting circuit diagram:
