title: SD card emulator
body: <p>I have one project to do.
  I need to transfer photos from camera to PC, i need to use SDcard interface it is SPI i hope ).
  Because usb transfer is not in option, so i think that i connect some microcontroller or raspberry pi instead of sdcard and emulate sd card and from microcontroller i somehow send it (via usb or ethernet)to pc. this whole operation (wrom camera to pc) must be realy quick (1-2s) and photos are 2-4Mbyte. Do you have any tips how to do that or what microconroller chose?</p>
  
  <p>scheme:</p>
  
  <pre><code>    SPI                     as SD emulator     USB/Ethernet
    |camera|---------------&gt;|microcontroller| ---------------&gt; |PC|
  </code></pre>
  
  <p>thanks for advices and ideas.</p>