micro sd shield with arduino mega 2560

Using Arduino Storage
1

Hi,
I was wondering if anyone might be able to give me some guidance. I have an arduino mega 2560, and a sparkfun micro SD shield. I have a PNY micro SDHC card in the shield. The card is formatted with fat32. I hope to eventually build a data logger, but i have been having trouble getting the arduino to recognize the card.

These are the following connections on the board.

shield->arduino

pin8->pin53
pin11->pin51
pin12->50
pin13->52

these connections should be correct. using the CardInfo in arduino 1.0.1
/*
SD card test

This example shows how use the utility libraries on which the'
SD library is based in order to get info about your SD card.
Very useful for testing a card when you're not sure whether its working or not.

The circuit:

  • SD card attached to SPI bus as follows:
    ** MOSI - pin 11 on Arduino Uno/Duemilanove/Diecimila
    ** MISO - pin 12 on Arduino Uno/Duemilanove/Diecimila
    ** CLK - pin 13 on Arduino Uno/Duemilanove/Diecimila
    ** CS - depends on your SD card shield or module.
    Pin 4 used here for consistency with other Arduino examples

created 28 Mar 2011
by Limor Fried
modified 9 Apr 2012
by Tom Igoe
*/
// include the SD library:
#include <SD.h>

// set up variables using the SD utility library functions:
Sd2Card card;
SdVolume volume;
SdFile root;

// change this to match your SD shield or module;
// Arduino Ethernet shield: pin 4
// Adafruit SD shields and modules: pin 10
// Sparkfun SD shield: pin 8
const int chipSelect = 8;

void setup()
{
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}

Serial.print("\nInitializing SD card...");
// On the Ethernet Shield, CS is pin 4. It's set as an output by default.
// Note that even if it's not used as the CS pin, the hardware SS pin
// (10 on most Arduino boards, 53 on the Mega) must be left as an output
// or the SD library functions will not work.
pinMode(53, OUTPUT); // change this to 53 on a mega

// we'll use the initialization code from the utility libraries
// since we're just testing if the card is working!
if (!card.init(SPI_HALF_SPEED, chipSelect)) {
Serial.println("initialization failed. Things to check:");
Serial.println("* is a card is inserted?");
Serial.println("* Is your wiring correct?");
Serial.println("* did you change the chipSelect pin to match your shield or module?");
return;
} else {
Serial.println("Wiring is correct and a card is present.");
}

// print the type of card
Serial.print("\nCard type: ");
switch(card.type()) {
case SD_CARD_TYPE_SD1:
Serial.println("SD1");
break;
case SD_CARD_TYPE_SD2:
Serial.println("SD2");
break;
case SD_CARD_TYPE_SDHC:
Serial.println("SDHC");
break;
default:
Serial.println("Unknown");
}

// Now we will try to open the 'volume'/'partition' - it should be FAT16 or FAT32
if (!volume.init(card)) {
Serial.println("Could not find FAT16/FAT32 partition.\nMake sure you've formatted the card");
return;
}

// print the type and size of the first FAT-type volume
uint32_t volumesize;
Serial.print("\nVolume type is FAT");
Serial.println(volume.fatType(), DEC);
Serial.println();

volumesize = volume.blocksPerCluster(); // clusters are collections of blocks
volumesize *= volume.clusterCount(); // we'll have a lot of clusters
volumesize *= 512; // SD card blocks are always 512 bytes
Serial.print("Volume size (bytes): ");
Serial.println(volumesize);
Serial.print("Volume size (Kbytes): ");
volumesize /= 1024;
Serial.println(volumesize);
Serial.print("Volume size (Mbytes): ");
volumesize /= 1024;
Serial.println(volumesize);

Serial.println("\nFiles found on the card (name, date and size in bytes): ");
root.openRoot(volume);

// list all files in the card with date and size
root.ls(LS_R | LS_DATE | LS_SIZE);
}

void loop(void) {

}

I cannot get the arduino to recognize the card. I've also tried other wiring. Does anyone have any idea as to why this card is not recognized?

2

Do not connect pin 8 to 53. Leave it alone. The others should be jumpered. Try this code

#include <SD.h>

void setup() {
  Serial.begin(9600);
  Serial.print("Starting SD..");
  if(!SD.begin(8)) Serial.println("failed");
  else Serial.println("ok");
}

void loop() {
}
3

Ok, so with this code, and this hookup

pin11->pin51
pin12->pin50
pin13->pin52

common ground, and the 3.3 and 5v hookups plugged in. There are no other connections on either board. I still get that the sd startup failed.
Any Ideas on how to troubleshoot this? (the card is formatted with fat32)

Thanks for all of your help!

4

also, I know the micro sd card works in the sense that I have been able to write data to it...just not through arduino

5

There are no other connections on either board.

If this means the shield is plugged into the Mega with those pins jumpered, that should do.

If this means ONLY those pins are connected, and you have not connected digital pin 8 to digital pin 8, then it won't work. Don't connect pin 8 to pin 53. Both will be outputs and they will fight. There will not really be a winner, but eventually one will lose.

6

Thanks SurferTim!

everything works great!