[Pete] has put together a fairly simple writeup on building a wireless USB tether for your DSLR. He’s basically using a pair of USB wireless adapters and a battery pack. In his original version, he did some slight modification to the dock that powers the USB dongle, adding his own battery pack too. He notes that this whole project can be done without the effort he put into it, at a little more expense.  The only improvement we think would be nice would be a better way to package it to keep it out of the way while you shoot.

Former Hack a Day contributor [Will] has been using a Eye-Fi SD card to automate his photo transfers. Unfortunately this requires using Eye-Fi’s software and talking to their servers. He used [Jeff Tchang]‘s replacement server written in Python to recieve the images from the card. [Will] manages his own online photo gallery using Gallery 2. To get the images uploaded, he added a call to GUP. Now all of his photos are transfered just as easily as with the standard Eye-Fi but without all of the middleman.

[photo: Eye-Fi teardown]

[les robots] had a defective Eye-Fi card on his hands and when a replacement was sent, he was told to destroy the original. What better way to ‘destroy’ something than opening the case? The Eye-Fi is an SD card with a builtin WiFi radio so it can upload images while remaining in camera. One version uses Skyhook’s location service to geotag photos. You can see a few photos of the dismantled card on Flickr. The board is manufactured by Wintec. The wireless side is handled by Atheros’ ROCm, the same low power Radio-on-Chip module you would find in a mobile phone. The flash memory comes from Samsung and the antenna is along the back edge, where it has the best chance of getting signal.

The WiFi uploading Eye-Fi SD card made a big splash when it was first introduced, but now Eye-Fi has a whole line of different products. The top of the line is the Eye-Fi Explore, which supports geotagging without using a GPS. Instead of GPS hardware, it uses the Skyhook Wireless Wi-Fi Postitioning System, which correlates the position of the Eye-Fi’s access point to GPS locations, creating virtual GPS functionality. This allows photos taken with the Eye-Fi to be be geotagged. Of course, the accuracy of the system is noticeably lower than true GPS and seems to be affected by a number of external factors, but it is still accurate enough to tag the photo within the immediate vicinity of where it was taken.

WiFi positioning is great feature, but certainly not limited to photography. Since the Eye-Fi is at its core SD storage media, you could probably have it geotag data saved to the card, even if it wasn’t created by a digital camera..