Montaigne, Mike writes:
>
>         I am just getting started with web video and my question is, are
> you working on the same thing?  (Re: Your comment(s) "The motors would
> be controlled via a PIC (16F84) with a serial interface back to my Linx
> box and it's http server.")

I've built a linux controlled pan/tilt + camera and access it through a
web page.  So it can be done.  I have a picture of it and the dummy
control panel on my web-page at http://www.hazmat.com/~mjb/robots/ .

>         This should allow me to capture a color image in better
> resolution and FTP at a much faster rate.  I can send pictures using
> SnapCAP and hopefully WebCam32 and I think I understand how to implement
> hardware control (PAN & TILT etc.) through RS232 to a PIC etc. using
> steppers or servos and but HOW DO I SEND COMMANDS / IMPLEMENT SOFTWARE
> TO CONTROL THE CAMERA FROM A DIALED IN WEB USER?   We are controlling
> experiments remotely, sometimes from our office, sometimes from home,
> and sometimes at a off site university.

You need to investigate CGI (common gateway interface)  This is the standard
for running programs from a web page (interactively)  It is also possible
to use Java/javascript, but CGI gives the widest possible audience.  Perl
is by far the most popular language to use under CGI.

I use a quick-cam for my camera, and for the pan/tilt head I have steppers
(for now).  I would strongly suggest avoiding steppers- they are far from
ideal for this purpose.  I used steppers ripped out of old disk drives, while
cheap, it is just too much mass for the steppers to control reliably (the
step motion easily induces oscillation in the camera assy. that is difficult
to damp).  I am in the process of building my own rs232 controlled PIC
based pan/tilt controller to replace the stepper assy.  This new pan/tilt
will use servos.  The one big disadvantage of servos is the limited
angular range of the motion.  I have some ideas to overcome some of these
limitations, but without more expensive servos or a more complex mechanical
arrangement you are limited to ~180 degrees.

The original incarnation was controlled with a digital I/O card from
a linux box, with drivers written by me, with discrete logic controlling
the steppers.  Now that I can program pics, I'm putting a lot more smarts
in the controller, which lets me have a much higher lever interface to the
pan/tilt.  This new set-up will let the aiming be repeatable.

If anyone would like to talk further, contact me privately (off list).

Matt

-----------------------------
Matt Bennett                |
mjb@hazmat.com              |
http://www.hazmat.com/~mjb/ |