Best of Both Worlds: Hacking an EyeFi SD Card to run CHDK

I'm in the midst of building a book scanner for archiving purposes. My book scanner is based on using 2 matching inexpensive high resolution point-and-shoot cameras (Canon Powershot A470), running hacked firmware (Canon Hack Development Kit) to accept external trigger control, and Eye-Fi brand SD memory cards to automatically upload images directly to the computer, with no need to tether (or remove) the cameras to get the images.

The Eye-Fi Memory cards have built-in Wi-fi controllers that automatically upload images to the internet. You can have them upload videos and pictures direct to YouTube or Flickr. I got (2) matching 2GB Eye-Fi Cards for $20 each at Woot! This way, the book scanner can work systematically through a book in an hour, and only need to shoot pictures and flip pages. This also allows the book scanner to be slightly more portable, as well. Mastering the final images into paginated PDF files will be another discussion...

To get the camera to boot CHDK, the SD card has to be placed in the “lock” position by flipping a switch on the of the card. However, the Eye-Fi SD Card has no such lock, by design. After following Greg Klein's advice and using an Xacto blade, I cut a slot in the side of the card, permanently locking it.

Tools Required: Sharp X-Acto Knife

Line up a regular SD Card, make Notches at ends of the 'lock' cutout

Cut Trenches as deep as the cutout should be on both the top and bottom.

Work it until the plastic comes free. It's easy to cut, especially once you get a few passes through the soft plastic. Be careful working with an X-Acto blade! You can injure yourself easily. Always cut away from your body!

Close Up of Final Notch

No damage to the internal memory chips; it’s still able to save images, even in the locked position. A hint of Scotch tape, placed over the new slot, will 'unlock' the card for stubborn readers.

Eye-Fi Before, Eye-Fi After beside the standard SD Card