This is a wonderful little SD card interface module. It is easily interfaced as a peripheral to your module. Through programming, you can read and write to the SD card.All SD Card works on 3V interface so if your microcontroller is working on 3V you can use this board readily. The interface board provided is for microcontrollers running at 3V. R1, R2 & R3 are pull up 10K resistors as required by SD Card to operate correctly.