Hi, all.

I'm planning to make a video capturing device using a PIC
and a PC parallell port. 

What I have is a composite 1 V p-p video signal (monochrome, no color bursts)
(The signal is CCIR, 50 Hz field frequency, interlaced)

I have a lot of ideas on this, but I would appreciate any input.

What I have been thinking is to use a sync separator (LM 1881 from National 
Semi)
This chip outputs horizontal sync, vertical sync and odd/even field information.
Giving the PIC these signals will enable it to determine the start of each 
frame and
also each line.

The problem is that a line lasts only 64 uS, and the video signal therefore has
to be sampled 400 times to get a horizontal resolution of 400 pixels.
At least this is what I'm aiming for.
I don't need more than 8 bits resoulution on the sampling, probably less.

Another problem is that I will need some kind of buffering, probably the 
entire frame, since the PC-parallell port is pretty slow. 
Maybe using ripple counters to address some kind of memory will do the
trick? The PIC would of course control everything.

I'm planning to use (and don't you dare laugh :-))  the 16C84 in this project, 
mostly
because I don't have a programmer that supports anything else. 
(My programmers are both the PICBlaster and the AN589 type. I've been
using the PIP-02 software for the PICBlaster and different types of software for
the AN589)


Any suggestions, good ideas etc?


Cheers

 -Oyvind

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'Oyvind Kaurstad, R & D Engineer, ABB Flexible Automation'

Email : oyvind.kaurstad@nofac.abb.no

//////// My worlds are colliding! - George Costanza \\\\\\\
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