Hi,
I've never used an SD card with an Arduino before and unfortunately don't have a datasheet for this breakout board, but I did a little research and here's what I found:
The Arduino can communicate with the SD card module via SPI (Serial Peripheral Interface Bus).
The SPI bus specifies four logic signals:
- SCLK : Serial Clock (output from master).
- MOSI : Master Output, Slave Input (output from master).
- MISO : Master Input, Slave Output (output from slave).
- SS : Slave Select (active low, output from master).
The SPI bus on the SD card breakout board operates at 3.3V and the Arduino UNO is a 5V device, so you need a level shifter in order to not damage the SD card.
You can use a resistor voltage divider as you mentioned, but if you do so make sure to use lower values such as 1K and 2K. The issue with using a resistor voltage divider is that the waveform will be attenuated a little, which could cause problems depending on the SD card used. Higher resistor values exacerbate the problem. With that said, the Arduino SPI bus operates at 4MHz by default, so in all likelihood a resistor voltage divider would work fine.
If you don't want to roll the dice with a resistor voltage divider, then you can use a level shifting IC. This breakout board would be an easy solution for you, or you could by an IC and make your own circuit on a breadboard.
Whichever solution you choose, the code on the Arduino will not be any different.
Let me know if you run into any problems and I'll do my best to help!