simple cameras for chessclock project

Regular webcam?

Thank you for your feedback, Padu.

A regular webcam uses USB. Isn't this the hard way? I was actually more
thinking about a CMOS Image Sensor. (I guess that's what inside one of
those webcams) That would be easier and cheaper to use, no?

But it doesn't have to be a CMOS image sensor per se. I am just looking
for something that is easy to connect to my circuit. Is a webcam
easier? (I don't know).

Maybe I should make things a bit more clear:
The camera should be connected to the clock, and the clock is connected
to the pc. In other words, the camera is not directly connected to the
pc. That is because I would like to extend the project in a later stage
and make it a standalone clock. the clock would then save the pictures
on a FlashCard for example.

Did anybody try this before? Or can anybody advice me a certain camera
or a certain image sensor, etc...

Thank you :)
BramGo

I don't know about cheaper. Webcams are very cheap these days. Yes, they are
USB (with a couple of firewire exceptions), and there are plenty of
libraries for dealing with images from USB cameras using either directX
(directShow) or WDM streaming. Take a look here for one example:
http://www.robin-hewitt.com/framecap/


For one of my robots, I'm using a CCD "boxy" firewire camera. The nice thing
about it is that the manufacturer provides the API to talk directly with the
camera, but these are more expensive ones (from $400 to $4000, withouth
lens)


On that matter, some cameras have a trigger input. When they see a signal in
this port, they capture one frame with very small latency. If you are not
connecting the camera to the pc, then you'll probably have to worry about
interfacing the image with your circuitry... not a trivial task.


What price range are you looking into? There are too many options.

Cheers

Padu

Something really really cheap.
maximum 30euros.

The picture can be black and white. The resolution should be
medium-quality though.

The idea is to let a PC write down a game record based on these
pictures. (I did a project on neural networks that should be capable of
doing this).
(But it's only a project, so if it would turn out the resolution should
have been better, it's not a disaster, then I'll just simplify my
project and make it a connect4-clock instead of chess-clock or
something like that).

<...>

an easy way out might be to buy a cheap digital still-picture camera that
stores
its pictures on flashcard, and then add a switch from your clock in parallel
to the shutter button of this camera. HTH

    Peter

If you're looking for a challenge, check this out:
http://www.sparkfun.com/commerce/product_info.php?products_idc7

For something simpler, try the CMUcam or one of these:
http://www.drrobot.com/products_wirobot_list.asp?categoryID=9
http://www.quasarelectronics.com/cmos_cameras.htm

The easiest thing would be to connect a USB webcam directly to the
computer and just have the chess clock communicate over the serial or
parallel port.  Intel's OpenCV has a highgui library that simplifies
interfacing with USB cameras.  I've used it for several projects; my
only gripe is that the framerate seems to max out at 15Hz.

Sending a 320x240 pixel image, with 3 bytes per pixel, will take a while
at 115200 baud...  Probably too slow for a chess clock.

Later,
Daniel