: Cassie Carstens wrote:
 I was hoping to 'scan' an area, say from left to
> right to find the hottest spot and the scan vertical for the same and
> at the crossing aim a shotgun........

Cheap b/w video pin cameras can do this job easily.
It doesn't need high resolution, since looks like there is not such
thing of good resolution in actual infra-red technology, except the
expensive ones.

Ironically, those cheap b/w video cameras, can receive a wide
spectrum of light, including infra-red "with great sensitivity".

For tests, I bought one of those "toy" cameras, b/w, works with
4 x AA cells and a cable to connect at the VCR, cost was $35.00.
Disassembling it, the complete video circuit is a small board
less than a square inch. The only connections are;  +Vcc, Ground,
Video Output. It is a composed video signal, with syncs.
Comes with an attached lens over the sensor chip.

At the dark, using a ordinary IR remote control as iluminator,
this camera shows at the TV a person's face at one meter away.

I wonder if somebody already did a software to analyze video
signals with a PIC unit, even that not reading all the bandwidth
existent in a video signal, but something, like 64 dots per
horizontal line is only 33k6Bits per frame, 672kBits/second.

One can say that it is not totally necessary to read all the
525 lines of signal, so reading one each eight, will give a
dot matrix image of 64 x 64, so 4096 bits to analyze, but the
reading bandwidth at that one line readed still 672kHz/second,
if reading 64 dots per line.

Using a cheap 8 bits ADC, it would be easy to locate the
high concentration of IR in the image, as the X-Y coordinates
you said above, as the "+" cross-hair target.

The V and H syncs, that need to be decoded, could trigger
interrupts to the PIC, so the data analyzes routines would
know what is going on.

To scan all the image, single delays and counters could be
produced, so the second reading could get the line #2 of each
horizontal 8 lines, the third reading gets the #3, and so on,
until after 8 readings, all the 525 lines were readed, 65
at a time.
A horizontal line has 63.5 us of time, so the 64 readings
need to happens inside that time window.  It means one reading
each microsecond aprox.  If at the second reading of the same
line, the circuit waits half microsecond (500ns) before starts
to read one bit each microsecond, it will get the intermediate
IR level between two dots readed at the first scan. If instead
to wait 500ns, it waits steps of 100ns, in 10 scans of the
same line it can scan 640 dots per horizontal line.
This is a way to scan a high speed signal with a low speed
processor.

Any idea or volunteer?

Wagner