SeeedStudios SD shield and Mega

Forum 2005-2010 (read only) Hardware Interfacing
1

I am having a problem writing to an SD card via the seeedStudios SD Shield V2.1. There have been many topics which have danced around this problem, but none that helped my particular problem.

My setup:

SPI pin mapping (I am just wiring the pins into the mega)
Sdt arduino pins Mega Pins
11 50
12 51
13 52
10 53

I am supplying 5 V to the unit thru te 5v V+ and ground pins

Using micoSD (with an adapter) card formatted (using windows 7 utility) FAT32

I have an existing file on the SD card with a single ASCII line in it.

Code snippets:

File mySD;
..........
SD.begin();
.....
pinMode(50, OUTPUT);
pinMode(51, OUTPUT);
pinMode(52, OUTPUT);
pinMode(53, OUTPUT);
......
mySD = SD.open("MWEL.CSV",FILE_WRITE);

The sketch hangs (suspends) on the SD.open statement.

Any ideas anybody? I have seen some conflicting information about pin mapping, as well as a discussion about supply voltages.

Rick

2

Using micoSD (with an adapter) card formatted (using windows 7 utility) FAT32

What library are you using? Typically, the SD cards need to be formatted FAT16.

3

Using the bult in library in V22 - states FAT32 works.

4

Wouldn't take that much effort to format it as FAT16 and see whether it makes a difference, would it? Then, we'd all know. That is, if you reported back.

5

I guess so, but here is a direct quote from the Arduino.cc reference documentation:

" It is built on sdfatlib by William Greiman. The library supports FAT16 and FAT32 file systems on standard SD cards and SDHC cards."

The card was (I think) originaly formated FAT16 before I reformated it. Did not work then either.

Rick