Command to keep compatible camera on

[Lorenzo Lucchini]

I know Eye-Fi cards can instruct cameras that are compatible with them ("Eye-Fi connected") to stay on while transfers are in progress. I assume they do this by communicating through the EYEFI/ directory.
Do you know the exact commands (i.e. file content) that's needed for this?
I ask because I have a different WiFi SD card (not an Eye-Fi, but a PQI Air Card that's running a modded Linux) and I'd like to make it emulate the Eye-Fi's command to do this.

[Dave Hansen]

It's not wired up to the user interface anywhere, but the method to do
it is in eyefi-config.c::print_transfer_status().

[Lorenzo Lucchini]

That was a quick reply! I'll have to study that a bit.

I saw you also posted on the blog about the D90 receiving this information through a STATUS file in the EYEFI/ directory, is that an older method? That doesn't work on my camera (a Nikon P7800), but honestly I'm not really sure I'm successfully tricking my camera into thinking an Eye-Fi is connected at all. The four files in EYEFI/ need to be 16384 bytes, right? Or did you have a better script to initialize the card somewhere?

[Dave Hansen]

On 10/30/2015 03:35 PM, Lorenzo Lucchini wrote:
> That was a quick reply! I'll have to study that a bit.
> I saw you also posted on the blog about the D90 receiving this
> information through a STATUS file in the EYEFI/ directory, is that an
> older method?

I _think_ so. I have some vague memory that they changed the protocol
on later versions of the card. I'm not sure how this would have worked
with older cameras, though.

You can always try to implement both things.

Which card do you have, btw? I'd love to get rid of my Eye-Fi cards.
They're basically doorstops now. Eye-Fi doesn't care about the old
cards at all.

> That doesn't work on my camera (a Nikon P7800), but
> honestly I'm not really sure I'm successfully tricking my camera into
> thinking an Eye-Fi is connected at all. The four files in EYEFI/ need to
> be 16384 bytes, right? Or did you have a better script to initialize the
> card somewhere?

Actually, the camera will recognize the card without those files if
memory serves. I think the volume-id of the SD card is the most
important thing. Maybe the volume name too?

See "-i" and "-n" in the mkfs.vfat manpage under Linux.

[Lorenzo Lucchini]

Ah, thanks! I had gotten hints from your blogs that the serial number / ID may be important, but was at a loss on how to change it from Linux (Google would suggest using dd...).

I have a PQI Air Card, which is actually an SD-to-microSD adapter: that's nice because I can use my fast class 10 microSD card in it, with no performance hit from within the camera. Sadly, though, there IS a very large performance hit when the PQI itself reads the card and sends data over through WiFi: in fact, it doesn't pass the 1 megabyte per second mark, which is slower than my internet connection. The problem isn't with the WiFi connection, but with the actual reading speed from the microSD card.

Still, it's a nice card, because it runs Linux and it's very easy to reflash with your own kernel and root filesystem (but even without doing that, it comes with open FTP and root telnet services... a gaping security hole, for sure, but convenient!).

It's based on the KeyASIC 2000 SoC, which the Transcend WiFiSD and the FluCard also use. These three cards are virtually identically, except from the firmware and the fact the PQI is a microSD adapter, while the other two are plain cards.

I am actually running Debian in a chroot on this card now, and serve files through MiniDLNA and SMB.