Mirco SD breakout board voltage question

[tom__pollard]

Hello!

I'm currently a final year student at the University of Le eds in England studying mechanical engineering.

I've just purchased the breakoutboard to include into my project, which is a GSM based pH sensing unit, with the aim of using micro SD as a local storage platform in-case of mobile network failure.

My question is, all the wiring diagrams I can find show the 5V pin being used with the Arduino, but from what I can read on the datasheet it should be compatible with 3.3V

It would be really great if I could use the 3.3V Arduino Pin, if so do I still wire from the 5V indicator on the breakout board, or should I add a wire from the 3V indicator.

Cheers

Tom

[adafruit_support_mike]

The SD breakout has a built-in voltage regulator that will drop the 5v supply to the 3.3v the SD card likes.

It's a good idea to use the 5v supply for reasons that aren't immediately obvious: SD cards are power-hungry little oinkers, and the Arduino's 3.3v regulator can't provide enough current to keep the card happy. The 3.3v pin is limited to 50mA, and SD cards use up to 150-200mA when they're writing data.