In this Instructable, you will learn how to make an SD card socket that plugs right into a breadboard for less than two dollars in parts (depending on how you get them of course). I show you how to use a simple straight pin header and modify it so you can plug in an SD card and attach it directly to a breadboard for data logging and prototyping. This is quick and easy so you don't have to wait for a socket in the mail, or build/buy the SMD breakout board for it either.
Basic soldering skills and common tools are required.
I will cover how to make vertical and right angle sockets. Either 7 or 8 pin should work. 9 pin may require some modifications, I only used 7.
Step 1: Gather tools and materials
Soldering Iron, I use 45 watt but this is more than enough
a vise is very useful to keep from burning yourself
and at least 21 pins of straight male breakaway header pins
I got the header pins from my local electronics parts shop. Radioshack doesn't carry them as far as I know, but they can be ordered from various places around the internet for very cheap. It was 2 dollars for 40 pins at my local shop.
Here is the digikey part, it's a bit more that 2 dollars. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=A26513-40-ND
Same thing from Sparkfun
These are straight male breakaway header pins.
You could theoretically use right angle as well, but I used straight pins.
Step 2: Cut the pins you will need
Cut the header to the number of pins you will be using. You will need 3 sets of that length, for me, 3x7 pins.
Optional: one of the rows is just as a backing for the card. It would be possible to use just a couple of pins on the edges instead of a full row, but I didn't follow this route. The process would begin to be different around step 4, when you attach the second row of header to the first.
If you are doing a right angle connector, right angle header pins may lead to a cleaner result. I used straight pins on mine however and it worked well enough.
Step 3: Bend contact pins
Take one of the 3 header rows and place it in a vise, or a pair of pliers or vise grips. I held the short end of the pins to keep them from pulling out of the plastic.
Using the needle nose pliers, bend the pins just a bit at the base, so that the tip of the pin is about vertical with the edge of the plastic. See pictures for detail. Not all the pins need to be perfectly aligned. Bend them all against a table or flat surface to line them up better.
Now they need to be bent back on the tip so it is easy to insert the card. Again with the needle nose pliers, grip just a small amount and bend it back the other direction. Do this for all the pins. See picture for detail.
Step 4: Attach second row temporarily
Be sure the pins are facing the right direction, the bend should be on the inside of the socket.
So the solder joint is stronger and cleaner, we need to bend the bottom pins a little. This way we aren't filling so much space with solder beads. Grab both pins and squeeze just a little, so the pins are closer together. This may vary a little bit and isn't incredibly crucial that it be exact.
Step 5: Prep for soldering
Step 6: Attach final header row
Hold the last row exactly where you want it. Using the soldering iron, touch the tinned leads and the small amount of solder already there should hold the 2 pieces together. Finish all the other joints using more solder, and then add some solder to the first joint. Add a little more solder than necessary to ensure a strong bond, but not so much as to make a ball. These are partially structural, but you probably shouldn't be using this for anything that endures much force either.
You can remove the hot glue or whatever you used. The solder is holding the parts together just fine. It was only temporary anyways.
Step 7: Prototype your circuit
I made mine because I was building a data logger with my Arduino and a Memsic accelerometer, but the possibilities are endless.
Just be sure you don't short out pins 7 and 8, the socket can slide over to it, so be careful.
Step 8: Extras
Plus there aren't any pins on the backplane that could short against something! Thats never a good thing.
Thanks to frollard for the idea!
I've also included a pinout of an SD card by request. Here's the deal with the pins. An SD card has two modes, SD and SPI. Specifics on these can easily be found on wikipedia's SD card page. For the Arduino, however, only the SPI mode can be used. The SPI mode only uses pins 1-7, leaving off the small one and the recessed one (8 and 9). SD mode rearranges some pins and uses all of them.
Here is the pinout for SPI mode:
1 - Chip Select*
2 - Data Input*
3 - Ground
4 - 3V3
5 - Clock*
6 - Ground
7 - Data Output*
8 - NC
9 - NC
*these are 3.3V logic lines. All but 7 are inputs to the card, and so must be brought down to 3.3V from 5V when using the Arduino Duemillenove. 7 is an output, and the Arduino can recognize 3.3V as high, so no voltage converter is necessary here.
Wikipedia has some great info on SD cards,
and pinouts.ru has a good writeup on the pinout,