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Topic: SD/MMC From the ground up (Read 63176 times) previous topic - next topic


Jan 24, 2010, 09:08 pm Last Edit: Jan 24, 2010, 09:09 pm by TBAr Reason: 1
Figured out the problem dont use this library at all lol.. that is if you are using a mega

used a different library working fine now.

Care to share a link to the library that works fine with the Mega?


just want to say thank you for sirmorris - you've done amazing job!!!  ;)


May 30, 2010, 07:58 pm Last Edit: May 30, 2010, 08:01 pm by itsthemedication Reason: 1
I have a arduino duemilanova (5 volt standard stuff), and I bought the seeeduino SD shield (http://www.seeedstudio.com/depot/sd-card-shield-for-arduino-v21-p-492.html?cPath=35).  Was thinking I had been taken for a ride till I found that the last SD card of a whole stack of SD cards, worked (a cheap 2 gig generic SD from microcenter).  The SD micros didn't work, and of course it says that SDHC is not happening.  It is particular.

Anyway. in the demo code, change pin 8 to pin 9, and it will work with either switch setting (3.3v or pin 9), that is if you:
  • make sure you have formatted the card to fat16
  • place file on the card called "data.log" (it's what the author uses)
  • make sure you open that empty file and add a single digit or character
  • and find the right SD card...

Then just type 'W' or 'T' and it actually works!  Although at a glacial pace.  Does anyone have any clues on speeding this up?  And, I too am interested in the Arduino Mega experiences (your post, TABr is not terribly helpful).

By the way, this shield covers up the VCC and all gnds.  You can still get to a +5 and a gnd using the ICSP pinout.  Pin 2 is +5v and pin 6 is ground (1 is marked).

1*  *2
 *  *
 *  *6




Hi all... I'm running into exactly the same problem that BLP had in Reply #16... I can't get the library to work with the Sparkfun SCP1000 pressure sensor via SPI.  Again, as with BLP, the SCP1000 code works fine if I comment out the FAT stuff, and the FAT stuff works weather or not I comment out the SCP1000 code (but the sensor returns all zeros).   I wrote my own implementation so unless he and I made the exact same mistake I'm thinking this is something in the FAT library.  

I'm wondering if indeed the SD code is responding even when the SD CS_ is HIGH.  Can anyone suggest any troubleshooting ideas?  (I *don't* have a logic analyzer).  SoftSPI is not an option ... Thanks in advance!


Hate to reply to my own post but adding intrigue... found some relevant info over on the sparkfun forums... seems others have had problems interfacing SCP1000 with other slaves on an SPI bus.  


Can anyone suggest any mitigation strategies that don't involved software SPI?  I'm going to comb through the SD library and look for dummy reads/writes and try changing their values - I know there is one in SDCard:Init... any other suggestions?  Thanks in advance!


Thanks sirmorris!!!
Finally, I made my arduino SD board successfully. It's so great and I can use it to record the data from motion sensor~~ 8-)

Thanks to all of you~~~


Sorry it took so long to get back the library that fixed all of my troubles was....


:-) Good luck

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