On Wed, 2002-12-18 at 16:21, wchast@utilpart.com wrote:
> This is a little project I am going to try to take on because
> the cost of a device available commercially is off on another
> planet.
>
> My wife has a live bait business, part of that involves delivering
> bait fish to bait and tackle shops. She has to count the buggers,
> and the count always is off regardless of WHO counts them. I started
> looking around for a fish counting device and found one that uses
> a optical scanner to count them as they go through a sluice. The optical
> part uses IR LED's to illuminate, and the detector or scanner uses
> what appears to be a column of detectors on the other side of the
> sluice, as a fish goes by it the detectors see the change in IR flux
> and can detect when one fish is ahead of the tail of the first fish
> thereby not opening all of the optical path.The fish will be anywhere
> from 3-6 inches in size.
>
> The manufacturer of this device wants more than $5K for it, I suppose
> that is ok for some government operation that has deep pockets but
> at $0.25/fish she will have to catch a lot of fish to pay for it, she
> also has to pay a truck used to deliver them and the guy and boat who
> actually goes out and catches them.
>
> The hardware does not look to be that great a deal. It is probably in
> the software where the cost is.
>
> My idea would be to feed the data from the sensors into the parallel
> port and read it at a rate such that I get each fish as it goes down
> the sluice.
>
> Now my question is this, do any of you have a idea of where I should
> start with this one. The hardware is a no brainer, I can get IR sources
> and detector arrays, I can build the sluice and other material, but I
> will need to come up with some software that can count the fish as the
> go in front of the detector. Has anyone done anything similar in terms
> of software?
>
Why don't you replace an old keyboard key with the IR source/detector
and then grab the scancode that gets sent? There has to be a method that
will not send a keystroke unless the IR is broken. If you can use a
keycode you can have the software in minutes.
-- Andrew Wyatt <awyatt@fewt.com> FEWT Software - http://www.fewt.com
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