Arduino SD card emulator?

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disconnector
 
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Arduino SD card emulator?

Post by disconnector »

Hi all!

I'm working on a project and I'm curious if I'm reinventing the wheel.

I have a device that reads impulse responses (guitar cabinet simulation generally but also reverbs) off of a SD card for real time convolution. The files themselves are very small - ~20MB. The device its self is pretty simple - you insert the card, turn a scroll wheel which displays the first couple of digits of the file names on the card on a 3 digit seven segment LED display, then press a button to load the requested file.

If I only had a couple of dozen files then this would be easy but I have literally thousands of files that I want to access. Three letter/digits is ridiculously too little to manage this number of files.

What i'm thinking about doing is using an Arduino with some storage and a nice display to organize the impulse responses. I can do this fairly easily. But the tough part is emulating the SD card for the device.

Is there a device or a library that I can use to directly connect an Arduino to a SD slot and make it appear that there is an SD card inserted? I know I need 3.3 - 5 volt level shifting but so far I haven't come up with a solution for the Arduino to emulate a SD card so the device can have a filesystem to read from.

Thanks for any tips or tricks!

Disconnector

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adafruit_support_bill
 
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Re: Arduino SD card emulator?

Post by adafruit_support_bill »

Not sure I understand what you are looking for. If the Arduino is pretending to be an SD card, where will the Arduino be getting its data from?

Perhaps a diagram of what you have in mind would be helpful.

disconnector
 
Posts: 6
Joined: Mon Jul 27, 2009 9:02 pm

Re: Arduino SD card emulator?

Post by disconnector »

Hi! I was hoping to have the Arduino use a second SD card to read the files from. The fundamental problem is that the UI on the device that I'm looking to hack sucks pretty badly. Organizing literally thousands of files via the first three digits (see the pic below) is almost hopeless. The device itself is amazing - I just want to hack a modern UI onto it.

Image

Basically I want to use the Arduino to interpose itself between the SD card and the card reader on the device. I want the Arduino to give me a nice UI and file structure (I've already done this before) and then fake the card reader on the device to make it think that it's still connected with an actual SD card. Is there a library or some sort of Adafruit device that will let me do this?

Thanks all!

Disconnector

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adafruit_support_bill
 
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Re: Arduino SD card emulator?

Post by adafruit_support_bill »

Interesting problem. Technically, I'd say it is possible. But definitely not easy - and probably slow. I checked around to see if anyone had done it, and came across this discussion over at electronics stackexchange.:

http://electronics.stackexchange.com/qu ... -emulation

disconnector
 
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Re: Arduino SD card emulator?

Post by disconnector »

I was looking at that same post.

SD cards are an SPI target for an Arduino right? So it's theoretically possible - but I'm not sure if I can get into bitbanging this out.

I wonder if this would be easier with a Raspberry Pi and Python. Hmmmmmm . . .

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