SD Card Break Out Board

[5c4r7]

I just picked up a SD-MMC break out board.

Model BOB-00204: http://www.lipoly.de/images/sparkfun_00204.jpg

I am hoping to mount it to a 5 1/4" faceplate for my Emulator II (along with the LCD and buttons of course). I am fairly novice when it comes to electronics but I am trying to learn whatever I can. I have managed to wire the LCD and buttons properly. However, this I am a little lost on. Can anyone please advice me as to which pins I need to connect on the HXC2001 board to the specific pins on the SD card breakout board itself?

Any assistance is greatly appreciated.

If this works. I will definitely post pictures. This might allow the unit to technically fit into a some 3 1/2" floppy bays without the need of case modification.

[Jeff]

I just picked up a SD-MMC break out board.

Model BOB-00204: http://www.lipoly.de/images/sparkfun_00204.jpg

I am hoping to mount it to a 5 1/4" faceplate for my Emulator II (along with the LCD and buttons of course). I am fairly novice when it comes to electronics but I am trying to learn whatever I can. I have managed to wire the LCD and buttons properly. However, this I am a little lost on. Can anyone please advice me as to which pins I need to connect on the HXC2001 board to the specific pins on the SD card breakout board itself?

Any assistance is greatly appreciated.

If this works. I will definitely post pictures. This might allow the unit to technically fit into a some 3 1/2" floppy bays without the need of case modification.

Using wires for the sdcard will probably make the device unreliable (signal integrity problems). And no mention about the potential EMC problem.

Anyway If you want really do this, have a look to the schematic.

[5c4r7]

Hmmm, bummer. I really like your products (I own 2 SD internal units, 2 SD external units and 1 USB unit). They would be far more beneficial to me if I could fit the SD model into a standard 3 1/2" bay. I know a lot of people have been looking for this and I am certain that if the build could be done by some affordable and simple means, you could be doing much much more business. Anyhow, your warning is duly noted and appreciated. For now, I have just dremelled a blank plastic bezel and fit the LCD and buttons on it for my Emulator II. I think I can do something similar to Arto's Ensoniq Mirage mod for my Prophet 2002 Rack unit: http://amazingdiy.wordpress.com/2010/11 ... iq-mirage/

And then I will use the 2 external units on the sampler models that I have smaller 3.5 floppy bays.

I will keep searching for ways to make these fit into a standard 3 1/2" floppy Bay. If I have any success, I will gladly share them.

Thanks for your help Jeff!

[► Evil E. ◄]

Using wires for the sdcard will probably make the device unreliable (signal integrity problems). And no mention about the potential EMC problem.

Hi Jeff,


I think that "5c4r7" made a very good point. As you have already realised yourself : being able to detach the LCD screen is extremely handy. This concept of modularity should be taken further to include all interface components :
- LCD
- LED's
- buttons
- SD Card slot

Let's take the Atari ST, for example :
Revision F doesn't work in there because of the way how the ST case is constructed around the original FDD.
Revision C leaves this ugly open gap and makes it extremely difficult (if not impossible) to properly operate the buttons and see the LED's. And I'm not even talking about the LCD here.

If you could create a newer version of the HxC SD Card Floppy Emulator that will allow users to place ALL the interface components where they want, you'll have a truely customisable product that will allow itself to be installed in a lot more devices than what you have right now. I'm quite sure that there are a lot of potential users out there that wish they could have this ability with the emulator (I am one of them, for instance).

And what about the EMI (Electro Magnetic Interference) when using a loose SD card slot attached to the main PCB through a cable ? Can you provide definitive proof that the emulator will in fact be unreliable, or is this just an unconfirmed thought ?
I'm quite sure that there are a lot of properly shielded cables that will allow the emulator to function properly without any interference at all.


I vote in favour of a FULLY customisable product that can to be used in a maximum of applications, and that means allowing the LCD, LED's, buttons and the SD Card slot to be detached from the main PCB so that users can place them where they want (or where there is room to place them).

I think that the LED's and buttons have solder points at the bottom of the PCB, so that already allows some modularisation/customisation there (although a pin header would be very nice to have there). But that still leaves the SD Card slot. If you can manage to include a pin header connector to attach the SD Card slot via a cable then you'd have one hell of a fantastic product on your hands, believe me !!!

[Jeff]

No.
I repeat once again : I cannot connect the SDCard with wires !!!

And what about the EMI (Electro Magnetic Interference) when using a loose SD card slot attached to the main PCB through a cable ? Can you provide definitive proof that the emulator will in fact be unreliable, or is this just an unconfirmed thought ?
I'm quite sure that there are a lot of properly shielded cables that will allow the emulator to function properly without any interference at all.

This will make the device unreliable AND there are a big EMC/EMI concern.

For your interest :
http://en.wikipedia.org/wiki/Electromag ... patibility

The SD card communication is working at 10Mhz. Attach a single wire on one of these signals and you will get a powerful emitter working with a large variety of frequencies (harmonic...). About EMC/EMI there are some law. We cannot do every thing we want...

About the reliability : add a single wire on one single sdcard signal, and you will increase the capacitance, the signal ringing and deacrease the signal quality.

[► Evil E. ◄]

Thanks for the link Jeff, that is some interesting reading.

Have you actually tried to connect an SD Card slot (all contact pins, not just 1) via a shielded cable to the emulator main PCB to see how much interference this creates and how unreliable the data signals become ?
Or are you just speaking in theoretical terms here ?
Would a shielded cable with a ferrite ring help ?

Sometimes theory and practice can be quite far apart.

I was wondering... We connect many different types of devices via cables to a computer. Why aren't these causing any reliability problems ? And copper trace lines on PCB's are also wires, why aren't these unreliable when they're even unshielded ?


I'm fairly ignorant when it comes to electronics, so please don't get mad at me because I ask a lot of questions. I just want to learn.

[Jeff]

I was wondering... We connect many different types of devices via cables to a computer. Why aren't these causing any reliability problems ? And copper trace lines on PCB's are also wires, why aren't these unreliable when they're even unshielded ?


I'm fairly ignorant when it comes to electronics, so please don't get mad at me because I ask a lot of questions. I just want to learn.

ok Some example :
USB 1, USB 2/3, HDMI, DVI, SATA, FireWire, PCIe, Ethernet ... : they use differentials pairs (http://en.wikipedia.org/wiki/Differential_signaling ).
Older interface :
IDE : 5V level, internal use only.
Serial port : +/-12V level, very low speed
Parallel port : 5V level, low speed (<250khz), shielded cable.

And copper trace lines on PCB's are also wires, why aren't these unreliable when they're even unshielded ?

Cause a magic thing : the ground plane ( http://en.wikipedia.org/wiki/Ground_plane )
And generally the traces length are shorter on a pcb than an external wire connection.

[markw]

Hey 5c4r7, I did exactly what you're asking on my SY99 and it works fine for me. As Jeff indicated, this could cause EMI or other reliability problems, but it seems to work OK so far. I didn't do anything special as far as shielding. The SD breakout boards obviously exist to do just what we are trying to do, and there are lots of other examples of long cables carrying digital signals inside most keyboards/samplers, so I'm not too surprised that this all works. If you want to see pictures of my install, check out my posting on the "Miscellaneous Keyboards/Samplers" page.

Here's a diagram I made showing the HxC pads connections to the SD breakout board. Note there are 12 pins called out on the HxC board but only 11 pins on the SD breakout board. That's because there are three ground (GND) pins on the HxC board - I labeled them all but you only need to connect any two.

Good luck!

SD Card Pinout.jpg (170.25 KiB) Viewed 5440 times