Webcam Control:

Webcams in different parts of the world are interesting to look at. What about one where you could choose your view? Try mine out!

I used a colour camera with a zoom & focus lens mounted on a standard pan & tilt bracket connected into a video capture card to create a webcam where the viewer chose the view.

The web side of the camera is a Linux box with a Win-TV card for the image capture. I've built a small interface driver board to do the movements that's hooked up to the parallel port.

The webcam is not designed for high usage levels so the software will need a bit of redesigning if load becomes heavy.

Currently what happens is as follows:

• User requests the webcam page.
• Perl back end requests an image capture from the Win-TV card and stores the image.
• Page is sent to user with freshly taken picture.

Or if a movement is selected:

• User requests the webcam page with arguments.
• Perl starts camera movement specified and waits for the time passed
• Perl back end stops the movement and requests an image capture from the Win-TV card and stores the image.
• Page is sent to user with freshly taken picture.

Components for the setup:

• 1 ULN2803 Octal Darlington Driver Array. (Maplin code QY79)
• 1 DIL socket for chip so you can replace it. (Maplin code HQ76)
• 4 DPDT Relays, nothing specific, (Maplin code N17AW did it for me)

And bits I found laying around

• Camera with motorised lens and pan-tilt mount
• Linux friendly video capture card
• Veroboard and a DB-25 plug
• Oddments of cable
• Solder, nuts & bolts

And all the usual tools, soldering iron, large hammer etc...

On to construction, but you may want a peek at the circuit diagram or the finished result.