Not exactly a build yet, but a start on one.

[TomHorsley]

My A480s finally arrived and seem to work well. The gphoto2 software cannot remote control them in order to do live capture, so I still need SDM to trigger the photos, but gphoto2 can fetch the pictures off the camera. I've updated my web page with simultaneous pictures I took of me pressing the mouse button I wired into the powered USB hub. It all worked the first time I tried it (which is always amazing).

On the platen front, I've decided on a design inspired by tinkertoys for the lever to lift the platen. Four pieces of electrical conduit (cheap, stiff, and easily obtainable, especially if you have some already) and four hunks of 2x2 with a pair of holes drilled through them at right angles, and I have a lever with nice round conduit to swivel in a slot in the back and act as a hinge, and the conduit is a nice smooth handle in the front as well. I can drill a couple of holes in the side conduit and dangle the platen from it on a couple of pins.

If I like the tinkertoy approach enough, I may use it for the camera and light supports as well.

[daniel_reetz]

A lot of people here would like the details on your A480/Gphoto2 setup... if you have a chance to write about it in detail, that would be most helpful.

[TomHorsley]

A lot of people here would like the details on your A480/Gphoto2 setup... if you have a chance to write about it in detail, that would be most helpful.

Actually, I'd like details myself. I've tried gphoto2 independent of SDM, so I don't know how they interact yet. The SDM web site talks about switching to usb mode to allow downloading a batch of images, and I suspect that will be necessary. I also don't know if gphoto2 will be able to delete the images on the SD card since SDM requires me to push the lock tab on the card in order to boot SDM. All things I need to experiment with.

[TomHorsley]

Corrected post: My lack of success with SDM previously was due to my ignorance of how to actually make my USB test script run on the camera. If I run this script on the camera:

@title USB Test
rem set to upload mode for 5 minutes to give me time to play
upload_images_for 300
end

My /var/log/messages file does report a USB device is plugged in as soon as I run the script, and it also looks like it is unplugged 5 minutes (300 seconds) later.

During the time the upload_images_for command is running, I can indeed fetch files off the camera with gphoto2 and delete files, so it looks like I need three things:

A way to notice when the usb interface becomes active - this seems easy enough: Using dbus-monitor --system shows that I get broadcast messages when I plug in the camera, and the strings associated with the message even include the serial number, so it should be easy to identify right and left.

A way to have the usb connection plugged into the computer, yet still be able to toggle the power on and off.

A somewhat fancier script on the camera to not only take the photo, but turn on the usb interface briefly after the photo is taken (the time it takes to raise the platen and flip the pages should also be plenty of time to download the images).

These all seem doable, so I'd think I can automate pretty much everything on the computer end and trigger it all by clicking the mouse to interrupt the usb power (or even use some fancy gadget to toggle the power via computer control).

In fact, I should be able to use an existing program I have (xdbusd) to prototype all this nonsense:

http://home.comcast.net/~tomhorsley/sof ... dbusd.html

Old, obsolete info from yesterday:

I've been playing with the A480 plugged into my computer USB port to see what happens, and running the recommended SDM build, as near as I can tell, nothing happens - it never looks to my computer as if a USB device was plugged in (though plugging it in does make it take a picture). Over on the CHDK forum thread on porting the A480, it sounds like some work on the USB PTP support has been done, and it may exist only on a development version of the CHDK software. I may try to figure out if I can download and test that and see if I have more success.

The best I could do now with the current SDM looks like leaving the card unlocked so when power cycled, it boots to normal A480 firmware. At this point, gphoto2 works fine, it can fetch the images and delete them on the SD card. Then I could manually boot the SDM firmware and take another batch of pictures.

More experiments are needed, but perhaps someday I'll be able to use a computer controlled relay to toggle the power on the USB line running from the computer to the camera, have the camera take a picture, then switch to USB mode long enough for the computer to download then erase the image, and go back to waiting for the next power toggle.

Or maybe Eye-Fi really is simpler .

[TomHorsley]

I've written up more details on some cobbled up prototype software that can download the images to my linux box during the scan:

http://home.comcast.net/~tomhorsley/har ... nload.html

Still need to figure out details of the SDM script I'd need to run, but I'm sure it is possible, I just need to climb the learning cure a bit.

[daniel_reetz]

The best I could do now with the current SDM looks like leaving the card unlocked so when power cycled, it boots to normal A480 firmware. At this point, gphoto2 works fine, it can fetch the images and delete them on the SD card. Then I could manually boot the SDM firmware and take another batch of pictures.

This makes sense to me because SDM uses the USB port in a non-standard way, so it is probably not available for PTP/mass storage transfer at all. Huh.

[TomHorsley]

The best I could do now with the current SDM looks like leaving the card unlocked so when power cycled, it boots to normal A480 firmware. At this point, gphoto2 works fine, it can fetch the images and delete them on the SD card. Then I could manually boot the SDM firmware and take another batch of pictures.

This makes sense to me because SDM uses the USB port in a non-standard way, so it is probably not available for PTP/mass storage transfer at all. Huh.

Actually, that was only my initial impression. Additional experimentation produced better results which I linked to above. I really can switch SDM into and out of USB mode and transfer files while it is in USB mode.

[TomHorsley]

After the brief diversion to demonstrate that I can indeed automatically alternate between taking pictures and downloading them to my linux box, I've gotten back on hardware, and made a little progress. I have my "tinker toy" platen lift lever and I've dangled my foam board mockup from it and convinced myself it will work:

http://home.comcast.net/~tomhorsley/hardware/scanner/scanner.html#More%20Platen

[TomHorsley]

My scanner still isn't quite finished (thought I have made more progress.

I've now started working on software to drive it all from my linux box:

http://home.comcast.net/~tomhorsley/har ... tware.html

[daniel_reetz]

Pretty exciting stuff... I've only seen user Benjamin's linux rig come closer to pure automation. You should really post a pic or a video to the forum once in a while to drive traffic over.