Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 29 Jan 2000 14:49:45 -0800
From:      Kent Stewart <kstewart@3-cities.com>
To:        Ken <webweaver@rmci.net>
Cc:        Troy Settle <troy@picus.com>, freebsd-questions@freebsd.org
Subject:   Re: Bar Code Scanning
Message-ID:  <38936E89.F44572A6@3-cities.com>
References:  <NDBBLOMCGLFPEPCPJEKKIEBOCAAA.troy@picus.com> <4.2.0.58.20000129134504.00b6ecb0@mail.rmci.net>

next in thread | previous in thread | raw e-mail | index | archive | help


Ken wrote:
> 
> At 11:54 AM 1/29/2000 -0800, Kent Stewart wrote:
> 
> >Troy Settle wrote:
> > >
> > > Get a scanner that plugs inline with the keyboard.  The scanner then sends
> > > text to the keyboard buffer.  FreeBSD won't give a hoot that it's
> > scanned or
> > > typed.
> >
> >This is definitely the easy way. However, these bar code scanners are
<snip> 
> >The ones I have used and programmed around were usually associated
> >with the serial port, use lasers, have a button or trigger to start
> >the scan, and read without touching the bar code like most of the
> 
> A bit more detail; what I'd like to be able to do is setup a scanner w/FBSD
> that udates inventory in a MySQL database.  I'm not a C/C+ coder, but am
> familiar with Perl.

These scanners are really primative tools. How are you going to do
your inventory? If you are talking POS, there are products that do
that but I have never been involved with anything like that. Walking
around and doing inventory is much more involved because you walk
around and accrue data and then you go back to a place where you can
download the information and update the database. The walk around
units are not cheap. They frequently come with developer kits that may
not of any value to FreeBSD. Linux is gaining in popularity and they
provide tools for that environment. With networking it doesn't matter
where you process the data because the database doesn't have to be on
the computer that scanned the barcode.

The hardest part of your project is probably getting the inventory
setup. If your inventory doesn't have barcodes on it, you have to
create the barcode for the inventory. There are a number of printers
that create a barcode label. The simple barcodes do upper case letters
and numbers. You want to be able to correctly read them even if the
are upside down. The printers I have experience with used a thermal
process and the labels were printed on crack_and_peel material. You
send the printer a text string with commands and it prints the label,
spools it, and then cuts the finished label off. The printed labels
are more fragil than an all plastic sticker that has a bar code
embedded in the plastic. 

I had a friend add barcodes to her book store and the data entry part
ran around 20% errors. The errors after you have an inventory is
different because if the barcode isn't in the database, you assume you
read it wrong and are told to reread the barcode. You could also have
an original data entry error and have to allow for it. It is much
nicer if the program creating and printing the new label also adds the
barcode to the inventory database. It may be wrong but it is at least
consistent.

The next is dealing with the inventory. You either have to find a
program that will do your inventory or you have create a program in
pearl or whatever that does the SQL to actually use the DB. I've never
used Pearl to do SQL but have been told that is both easier and
slower. The advantage is that you wouldn't have to learn C/C++. The
disadvantage is that you may have to do some of the raw functions on
your own. 

Each barcode scanner is different. Some just send a text string out
the serial line everytime it reads a barcode. This style was a problem
if there was any chance of the laser touching a different barcode than
the one you wanted the system to process. There wasn't an OOP's button
:). Writing a program from scratch can also be difficult. Carrying
every part to your computer to use a scanner on the keyboard to do the
inventory may not be convenient :). Using the FreeBSD system to
maintain the database is relatively trivial compared to actually using
it. There may be products out there that do some of this using
FreeBSD. We didn't use FreeBSD and I haven't been involved with it
since I started using FreeBSD. I have always felt that limiting your
self to a product that only runs on X system can be expensive as you
work around a bad choice. 

Most of our stuff was original such as barcodes that were laser etched
into material such as endcaps that were later welded onto Ziralloy
tubing. Every item in the plant had a barcode on it and this includes
boats that carried soft raw material thru a high temperature furnace
to convert the soft oxide into a hard form of ceramics. The boats
could come out of the furnace hot enough to melt a simple wand
scanner. I think there was a cooldown section for safety reasons but
they were still very hot when they came out through the furnace door.
Each item could be followed through manufacturing because of the
presence of the barcode and barcode readers. Canned products never
seemed to go beyond printing the barcode for soft materials such as
boxes and etc. and reading the barcode. Doing something with the
barcode was left up to you.

The really good Oracle tools only seem to run on some form of Windows.
There is something that runs on FreeBSD but I haven't used it. Doing
manual SQL database design and development can be really bad at times.
YMMV

Kent

-- 
Kent Stewart
Richland, WA

mailto:kstewart@3-cities.com
http://www.3-cities.com/~kstewart/index.html
http://daily.daemonnews.org/

SETI (Search for Extraterrestrial Intelligence) @ Home
http://setiathome.ssl.berkeley.edu/


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?38936E89.F44572A6>