Homemade
Home Security
Build a 4-camera surveillance system
and watch from any web browser.
BY DAVID BODNAR
My basement office/workshop is a fair distance from the front of
the house, and I frequently want to check the front porch for mail,
UPS deliveries, and the arrival of friends. I have experimented with
various ways of monitoring the activity there and have found none
as useful as a real-time video feed.
Getting video from a camera on the front
porch to a screen in the basement is a trivial
undertaking, but as projects like this are apt to
do, it grew into a $200 four-camera, full-color
system that can be monitored in my workshop
or from any web browser. Some commercial
systems can do the same thing, but they
cost much more or use only black-and-white
cameras. Meanwhile, I learned that switching
composite video signal is actually very easy,
doable with a 35¢ CD4066 analog switch chip.
START
1. INSTALL THE CAMERAS
First, of course, you’ll want to decide where
the cameras go. I have one mounted on my
front porch, aimed at the front door and mailbox; a second camera looking down on the
driveway, so I can see when someone arrives
by car; a third looking over the pond, garden,
and garden railroad; and a fourth giving a view
of the front yard. You’re welcome to see the
live camera feeds at n3enm.hopto.org:888
and operate the system controls at n3enm.
dyndns.org:8888.
The Harbor Freight security cameras
screw-mount to any beam and have a 6'
cord that terminates in a 6-conductor RJ11
(technically, RJ25) telephone jack. The jack
accepts an included 80' extension cable, the
other end of which splits into a yellow RCA
plug for composite video, a white RCA plug
for audio from the camera’s microphone,
and a barrel connector for 9V DC from the
included wall wart power adapter.
I haven’t set up the software to put the
cameras’ audio online, but I did connect the
audio from the front door camera to an old
pair of computer speakers in my basement
office. This lets me hear the sound of the
newspaper hitting the driveway when I’m
working in my office early in the morning.
The cameras and cables have proven to
be weatherproof when protected from direct
rainfall under a roof (Figure A), but the RJ11
connector between the camera cable and
the extension cable became corroded from
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