SD cards add cheap persistent memory to your project, but the holder takes a lot of board space. A smaller option is the microSD flash format. MicroSD cards are compatible with regular SD cards, and most come with a free adapter. We looked at four holders for our mini web server. Which should you choose? Read about our experience below.
Here’s a breakdown of the microSD card holders illustrated above:
Alps SCHA1B0100 $1.27 – Can you see pins through the holes in the first holder? They ‘re hard to see, and almost inaccessible. We didn’t find this holder very useful for prototyping.
JAE ST6S008V4AR1500 $1.46 – This is another model with pins located at the front, but these are further forward for easier access. It’s still going to be a pain to solder, avoid if possible.
SparkFun PRT-00127 $3.95 – Finally, a holder with pins at the back. This is a fairly easy-to-solder part, but it’s not ideal. The soldering tabs are very small and slightly recessed under the shield. It’s also the most expensive microSD holder we’ve seen. SparkFun has a Cadsoft Eagle footprint for this part in their library. We think Molex 538-502702-0891 ($3.58) is probably very similar. We used this holder with the mini web server.
Alps SCHA2B0300 – $1.27 – The long pins along both sides of this holder are easy to solder. The holder is reversed, meaning the card inserts upside-down. Reversed holders seem weird on an all surface mount board, but they fit nicely in through-hole designs. There’s no Eagle footprint yet, but we’ll send an SCHA2B0300 to the first person who makes one; here’s the datasheet (pdf).
Check out our previous parts posts: 0.1uF decoupling capacitors, the LM317 adjustable regulator, and tactile switches.
Does it have to be Cadsoft Eagle? I’ve used this part before and have the footprint for ExpressPCB.
coincidently, i already had this part created. i was looking into options when making the webserver pcb.
http://beastmasterelectronics.com/eagle/lib/alps-microsd.lbr
@beastmaster – thanks. I sent you an e-mail.
primer for those interested in writing to SD cards:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1206874649/8
@brad and all
All those arduino projects, and so hard to get the arduino, they have a ‘local’ reseller here but the shipping is like 40 bucks, which is substantially more than the product and seems insane frankly.
Reason I tell you this: Count your blessings :)
This is a stretch, but if you buddy up to your local GPS or cell phone retailer, you might be able to get a hold of some dummy models of old GPS or phones.
These dummy models often contain actual usb connectors, switches, and yes, even sd card connectors, all of which can be de-soldered and used in your projects.
I work at a radio shack and have scavenged some interesting stuff out of dummy models, sometimes even entire failed circuit boards loaded with SMD parts!
wwhat: you realize that you can just buy an atmega168 (or similar), 232 to TTL adapter, crystal, and that’s basically an “arduino”?
I’d throw in a breadboard as well.
Thanks for the info… This is a great series, keep ’em coming!
Intermediate between large SD cards and annoying-to-deal-with micro-SD is “mini-SD.” I picked up some cheap mini-SD cards from an eBay dealer, and found them pretty easy to deal with (see the web site.) MicroSD is a convenient card format, as you can get adapters up to either mini-sd or full-sized-SD cards. (as a card format, miniSD suffers from not being popular enough…)
jproach, i fully agree , an arduino is just a nice name for ATmega on board with a
jproach, i fully agree , an arduino is just a nice name for “ATmega-on-a-board-with-a-crystal-and-other-stuff-you-do-not-need”
I really do not like microSD. They are expensive and come in lower capacity. I recently replaced the RS-MMC in n770 with SD card (after hacking the cover).
I forgot my password, so i tried to format it, but it was still asking for the password
Beastmaster’s site is down
does anyone have a link to the alps-microsd.lbr file mentioned above?
Thanks
http://netload.in/datei7GPBPr7M8w/SCHA2B300.lbr.htm
End of Life: Scheduled for obsolescence and will be discontinued by the supplier.
The Yamaichi PJS008-2003-0 could work for prototyping.
It looks like the replacement is the SCHA5B0200. I’ve drawn the part in eagle and ordered a board with it. Will post link when I know it works.
Did you ever get around to test your eagle part? If so could you share it?
Since it’s an upside down SD card holder, it’s a little more intuitive if you mount it on the bottom of your board.
Yes, works great
https://bitbucket.org/ryan_neve/eagle-cad-libraries.git
It’s in SCHA5B0200.lib
I dig this “Parts:” thing… Could be very handy. Maybe a wiki?
Looking through Digikey’s great and all, but it takes quite a bit of time to determine things like you’re pointing out: pins are *under* the housing, no fun to prototype with.
The Sparkfun PRT-00127 is similar to the Molex 47352-1001. The chassis pads are slightly off (they still fit over them though with a slight offset, but the pins line up and it’s a pretty good replacement.