Sd card initialization fail

I have an arduino pro mini 3,3V for a temperature data logger with sd card breakout board. My issue is that suddenly sd card won’t initialize.In my Arduino Uno works perfectly but in my Arduino Pro Mini not. Any idea for that?
Any solution would be appreciate.


Without posting your code and how you´re wiring your circuit, all that people here can do is guessing.

My guess is that you don´t have enough power to the SD Card, since it needs 5V (works fine in Uno) but you´re trying to power it from a 3.3V Pro mini.

Depends on the SD card breakout you are using.

A 3.3V Arduino ProMini is best used with one of the SD card breakouts that have no electronics added.

Taking a look in your link, the description of your module says that:

"Power supply: 4.5V – 5.5V, 3.3V voltage regulator circuit board"

I´m still unsure that you can power it from 3.3V...

Anyway, you declare an object called "Myfile", but when you open the file you call it "dataFile".

Try changing the line:


myFile ="Data.txt", FILE_WRITE);

That module needs to be powered from 5V.

Powered from 3.3V, VCC on the Pro Mini, VCC on the SD card will be around 2.2V ...........................

Although I suspect that when it is powered by 5V, the logic output level on MISO is at 5V level.

Use a module actually designed for a 3.3V Arduino.

If something is working fine and suddenly stops, then its likley something has been broken.

You have not made clear how you have this all connected and we have no indication of what voltage supply it has or where its connected.

Ah, you tried a replacement SD board, you did not say.

I have not tried the combination you are using, with 3.3V ATmega328s I just use SD card adapter without the regulator etc, they work fine.

Why would the code work fine for a while and then fail completly and permanently ?

Have you changed your code?

I´m asking this because in post #4 your code started Serial at 115200. The figure in #14 shows Serial Monitor at 9600 displaying information correctly. If you´ve done other changes in your code, it would be better to post the version you´re currently using.

Anyway, the error you´re getting suggests that the SD card is not initializing. As you changed the board (SD?) we´re presuming the new board is not damaged. So, I still believe that your SD is not getting enough power to work. Another possibility (less likely) is that your D10 port of Pro Mini is damaged.

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