USB card readers are a dime a dozen. In fact, the one I have was only $10 bucks. However, I thought it would be fun to build my own. One man's SD Card reader is another man's Solid State Drive!
But what would that entail? I thought at first that it would be as simple as making an FTDI adapter connected directly to an SD card.
I then found the pinouts for an SD card. Looks like it uses MISO, SCK, and MOSI connections. So FTDI is out of the question.
So it looks like it's just a matter of mapping the pinouts to an Arduino. I then found this:
So it looks like it's pretty easy to get an Arduino to read/write from an SD card. However, I was under the impression that the SD card libraries for Arduino are limited to an 8.3 file format. That's no good for everyday file transfers to/from a PC or a Mac.
What needs to sit between the computer and the SD card to do the "talking"?
It may... be possible to use an arduino as card reader, but I would use a normal USB-card reader though.
You can do a lot with Arduino and SD's, but It take ages..... to read/write a few 100MB using an arduino, maximum transfer rate may be lower as 50KB/s.
There's huge amount of stuff you can do with an Arduino, but keep in mind that it's an 8-bit micro-controller with little memory running at a relative low speed. It's hard to make an exact comparison with PCs, but it has about the computing power of an 20 year old PC.
It's nice to use an SD to store data from sensors, read configurations and stuff, but for real speed a normal card reader is much faster and cheaper.
So how is it a no-name company in China can make a $5 USB stick no larger than the USB connector itself? How are they pulling it off? Why is it you can't make a DIY thumb drive? There has to be a way, not because it's better than a SanDisk or a Cruiser, etc...but because we can!!
Sure, you can go out and spend $5-$10 bucks on a USB card reader...but wouldn't it be cool to make your own mini "solid state drive"?
Maybe I could do somethign like this: Business Card. This guy created his own USB Mass Storage device as a business card. Granted it only holds a Meg of data. Maybe I could modify it to store data to an SD card instead of the 1M RAM chip?
ryemac3:
So how is it a no-name company in China can make a $5 USB stick no larger than the USB connector itself? How are they pulling it off? Why is it you can't make a DIY thumb drive? There has to be a way, not because it's better than a SanDisk or a Cruiser, etc...but because we can!!
Sure, you can go out and spend $5-$10 bucks on a USB card reader...but wouldn't it be cool to make your own mini "solid state drive"?
You forgot that the no-name company has a million dollars invested in manufacturing equipment and space and some dozens of qualified workers and circuit RD professionals and contracts to purchase bulk parts at cost you can't believe etc. If you can make such drive yourself for $5, that company would be able to do it at $0.50 and still make money. Your intellect alone is not able to beat capitals they own.
Using Arduino is not meant to be an alternative to or saving money on consumer electronics, it is to create things or even products NOT sold as consumer electronics, which is how and why arduino became popular.
I'm not looking to make a $5 USB card reader. I have plenty card readers and thumb drives already. I just want to make one of my own. If it costs me $50 bucks, then so be it.
I was just sitting around thinking of cool stuff to make and I though it would be pretty neat to make my own USB Mass Storage Device. Once I Googled for a schematic, I realized that it's not a matter of just chalking up a PCB and having it fabbed. I can't even seem to find a schematic. Why is this such a secret? Why is it so difficult to make something that you can buy at the checkout of a quickiemart for $5 bucks? Ever crack open a thumb drive? There's nothing to them. A RAM chip, a USB controller and maybe a crystal and a couple of SMD caps/resistors. I though this would be a simple little weekend project.
Check this out. This is exactly what I'm trying to make. Looks like a USB controller on the back under the blob and the top is just a card slot and a bunch of SMD componenets. How hard can this be? I just need to figure out what the USB controller is and what chip I can use to replicate the functionality. Size isn't a consideration. I don't care if the thing measures 4"x6".
Oh well...It was worth a shot. Seemed like it would have been a cool project.
In order to make this, you need a microcontroller fast enough to handle USB 2.0 and the interface on the SD card. No arduino will provide you such speed. Once you decide what MCU to use, get familiarized with USB 2.0 standard and write firmware that will behave as expected. The firmware part is beyond the Arduino community. Then you design a circuit board and secure parts. This process takes time and money but is only needed once. No company in their right money-making mind will let you have the firmware and circuit design for free. To learn how to do it, you will have to find more professional electronics forum for information.
ryemac3, I am also working on the problem of making my own custom USB disk, with some idea in mind.
I achieve some result with a FTDI FT4222 to talk SPI to an 16 GB SD Card (HC).
Contact me. see my web site www.MadeInTheUSB.net, if you are still interested.
