Re: text from serial port + IP camera + Debian for loss prevention?
On 04/09/2013 07:55 PM, Nick Lidakis wrote:
Forgive me if I'm not using the proper terminology or not explaining
this properly. This aspect of running a small business is foreign to me.
My wife and I run a small independent coffee shop and I'm the geek in
charge. I've got m0n0wall running great with the customer wifi on DMZ and
all our machines on a private LAN. We've got a recycled Pentium 4 running
Debian stable for our Music Player Daemon server. Motherboard is a Tyan
with real serial ports.
We have a mid-line Casio cash register setup that has 2 serial ports. 1
is dedicated to the credit card machine. The other can be connected to a
serial pole display. I understand that this second serial port outputs
formatted text of all buttons pressed and transactions processed.
This is also useful for overlaying this text with a CCTV camera connected
to a DVR. Though, this setup limits how you can search for mistakes or theft,
having to sift through hours of video.
I'd like to do the following with Debian: Use the text from the serial
port in conjunction with an IP network camera connected to our server. I'd
like to be able to search the text for particular triggers, e.g., look at
video whenever someone hits the NS (no sale) key to open the drawer.
I think I can connect the Casio to one of the serial ports on the server and
capture data through tty(?).
The text would not necessarily need to be overlayed but must sync with the video.
The Casio has a pretty accurate clock, running on 60Hz; the IP camera can
sync via NTP on our m0n0wall router.
I've Googled a few commercial solutions but they are very expensive and
are proprietary. One is this:
http://www.geovision.com.tw/english/Prod_GVDataV3E.asp
I'm thinking something like this must have been done with Linux for other
fields, e.g., scientific sensors outputting text on a live stream.
Any ideas or suggestions?
You mention going thru hours of videos. Perhaps the "no-sale key"
trigger is not so hot, unless you set up the system to record a few
minutes before that key press. Also, you can take a tip from the pros,
and run the video at about 8 frames per second, which is still
sufficient to identify persons and record their actions, but reduces
the total amount of recorded video. Finally, it would be a good
idea, if possible, to keep real-time copies of the video off site, in
case miscreants steal your computer or otherwise trash or burn
the premises. This should be possible using a short-range radio
link to some other nearby site. (I think you need something better
than a nanny-cam.) Probably a radio-linked network is the ideal
solution here. There are RF solutions that will work over a range
of a couple hundred feet to several miles, the latter requiring
outdoor directional antennas with a clear line-of-sight path.
You name yourself as the local geek, but if you're not sure you're
up to it, it would probably be worth your while to hire a programmer
to handle some of these ideas. Make sure the programmer can
handle Linux, if you want to use a Linux system--which I think is
a good idea, since it is _relatively_ immune to hacking.
--doug
--
Blessed are the peacemakers...for they shall be shot at from both sides. A.M. Greeley
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