SD.Begin(int, int. int. int) can only be called once.

[davidstellini]

Demo code:

include <SD.h>

void setup()
{
Serial.begin(115200);
Serial.println("Starting...");
if (!SD.begin(53,2,4,3)) { // chipSel, mosi, miso, sck
Serial.println(F("initialization failed!"));
} else {
Serial.println(F("initialization done."));
}

if (!SD.begin(53,2,4,3)) { // chipSel, mosi, miso, sck
Serial.println(F("initialization failed!"));
} else {
Serial.println(F("initialization done."));
}
}

void loop(void) {

}

Output:

Starting...
initialization done.
initialization failed!

Expected output:
Starting...
initialization done.
initialization done.

[Jeroi]

This is not bug. You only need to initialise Sd library once. You can then make checks with File myfile = SD.open("file") that shall return file or 0 if not working. You can check if (myfile) then do work.

[dariosalvi78]

Hi,

this is definitely a bug, in fact, if you have more than one SPI device you must call begin() each time you need to switch from another device to the SD card.
I have had the problem myself.

Solution:
in the file named SD.cpp, in function begin() (line 337) add this instruction before the return statement:
if(root.isOpen()) root.close();

this has solved the problem for me.

[ladyada]

this library fork is being archived - please use the SdFat Library instead (its much better) for any advanced SD card needs!