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microSD on EMX


#1

Hi,

I’m a bit unsure about how to connect a microSD to an EMX module.
I have read several related questions on the forum, but did not find an answer to mine.

The connector I want to use (Multicomp 460DE08C3) has the following pin layout:

1 DAT2
2 CD/DAT3
3 CMD
4 VDD
5 CLK
6 VSS
7 DAT0
8 DAT1

So, is this the correct way to connect it to EMX?

1 > IO40/SD_DAT2
2 > IO39/SD_DAT3
3 > IO44/SD_CMD
4 > SD_POWER
5 > IO42/SD_CLK
6 > GND
7 > IO43/SD_DAT0
8 > IO41/SD_DAT1

I’m a bit worried about pin2, which has to do with the CD part of that pin. Should there not be a seperate CD pin on the connector?

I’m a bit confused because the pins are diffrent compared to “standard” SD card, like beeing used on FEZ cobra for example.

Anybody who could help me understand?

Thanks!


#2

DAT3 can optionally be used for detect but we do not support that. If you need detect, then you need a card with detect pin.


#3

Wow, your fast!

Oh I see. No, I do not need card detect, because the card will always be in the holder. I will use it as storage for application settings and html files for the embedded webserver.

So this pin layout is correct then?

1 > IO40/SD_DAT2
2 > IO39/SD_DAT3
3 > IO44/SD_CMD
4 > SD_POWER
5 > IO42/SD_CLK
6 > GND
7 > IO43/SD_DAT0
8 > IO41/SD_DAT1


#4

No one able to confirm the pin layout?

I have to order the boards by the end of the week and it would be nice if I would know for sure…


#5

They look correct but obviously we do not give you a wrong answer. Please double check with one of the numerous open designs we provide.


#6

Gus,

Thanks for your answer. I will check your designs and see if I can find one with microSD on it.


#7

@ NickS: maybe this information can help you out: http://elasticsheep.com/2010/01/reading-an-sd-card-with-an-atmega168/


#8

Your pin layout looks fine. But I would search a microSD slot with mechanical card detect switch, so you can detect insert/removal of the card. F.e. the DM3D-SF http://www.hirose.co.jp/cataloge_hp/e60900232.pdf


#9

Wouter,

Thanks a lot! The link you send me in your first reply is very helpfull. I was a bit confused because the pin layout is diffrent compared to a “regular” SD card.

I I do not actually need CD for this project, but it’s likely that my next project requires it. I might as well do it right the first time…

I get started on drawing the Hirose connector in Eagle.

Prettige avond!