WTFO Do you have a schematic for that rats nest??????? geeze what a lot of wires --- On Fri, 12/10/10, John Yost <dtjay@xxxxxxxxx> wrote: From: John Yost <dtjay@xxxxxxxxx> Subject: //MARS R/ Fw: SD Card Pix To: rgn3_tech@xxxxxxxxxxxxx Date: Friday, December 10, 2010, 12:03 PM Didn't turn out to well but hopefully you get the idea. This wasn't my idea, but I'll take the credit-HI Google "arduino sd card" and you'll find much more detail and pinouts. Was able to write and read back 100 line text file. Since the sd card needs 3.3 volts I put this on the mega and used a voltage divider for the 3 input lines to the sd card In my set up I have the contacts toward the odd number pins and alligned with the socket index, the one used to make sure you put it on the floppy correctly. Then soceket pins 7,9,11,13,15,17,19,21,23 are connected to the sd card. Pin out becomes sd pin cable pin 1 9 - SS - chip select - this is actually the second pin on the card the first is pin 9 2 11 - Data In 3 13 - Ground 4 15 - Vcc 3.3v 5 17 - Clock 6 19 - Ground1 - both need to be grounded 7 21- Data Out - does not need voltage protection/help as the 3.3v is enuf to trip the threshold on 5v logic Other pins not used for SPI interface. http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1206874649/8 this web site shows the voltage dividers for the input pins. SRI for the long text but I needed to document this stuff somewhere JY