MicroSD card breakout board+ (id 254) with external power su

For other supported Arduino products from Adafruit: Shields, accessories, etc.

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
ddewaele
 
Posts: 3
Joined: Sat Nov 16, 2013 6:48 am

MicroSD card breakout board+ (id 254) with external power su

Post by ddewaele »

I'm using the MicroSD card breakout board+ (id 254) (http://www.adafruit.com/products/254) with my Arduino Mega using the standard SDCard library (#include <SD.h>) and it's working fine when powered through USB.
I can read / write to my 2GB SD Card that I pulled out of an old Android phone.

However, as soon as I hook up an external 12V power supply the SD library fails to initialize. With my lab power supply I noticed that as soon as I hook up > 6.5V I'm having trouble initializing the SDCard.

Everything is hooked up correctly as described on the product page and tutorial. The weird thing is that it is working fine as long as I'm using USB. The Arduino Mega + SD breakout board is hooked up to a card battery through an OBD shield.

If I "boot" the arduino using my laptop (USB), it initializes the SD properly. If I then continue to hook up the OBD cable (to power the arduino + obd shield from the 12V car battery) it also works.
But if I "boot" the setup by hooking it up to my OBD connection I'm never able to initialize the SD Card.

Any ideas what might be causing this ?

User avatar
adafruit_support_mike
 
Posts: 67454
Joined: Thu Feb 11, 2010 2:51 pm

Re: MicroSD card breakout board+ (id 254) with external powe

Post by adafruit_support_mike »

Are you taking power for the SD breakout directly from the OBD shield, or through the Arduino's regulator on the 5v pin?

Locked
Please be positive and constructive with your questions and comments.

Return to “Other Arduino products from Adafruit”