Video Security Monitor

We’ve already looked at the different types of computer video equipment in our previous article on webcam computer surveillance, here is part one of a three part guide to installing a dedicated security camera system using the best tools available on the internet.


USB Cameras

zoneminder_1USB cameras are the most prolific cameras available today. These cameras work fine indoors but will over expose as soon as they are pointed outside. USB cameras are also suffer from reliability problems. Tests we conducted showed that the USB camera usually needed to be reset (plugged out and in again) at least once a month. It’s not recommended to use USB cameras except for indoor sporadic monitoring.

You can get simple composite cameras from online stores such as Deal Extreme for as little at AUD $25 delivered to your door.
The benefits of these types of cameras is that they are cheap. Some of these cameras are waterproof which means you can mount them outside and if they break or get stolen it’s no huge loss. 1.3Ghz or 2.4Ghz wireless cameras are not recommended because they are not encrypted and are easily viewable by people nearby using the right equipment. (A potential bonus in a shared driveway situation perhaps?) These cameras will connect to your computer via a capture card.

Composite are great cameras to start with but if you’re wanting to use VMWare to house your zoneminder installation IP cameras are required. VMware server doesn’t support capture cards so IP cameras are your only option. There are USB capture cards available which should work with VMWare and although we haven’t had a chance to test them yet they are rumoured to be unreliable

zoneminder_2composite IR Camera

IP cameras come in three colours, WiFi enabled, Wired only or both. One of the big no-no’s with cameras is sending the signal over wireless. Most people know that wireless is hack-able, so you don’t want to be giving potential burglars a look into you garage. WiFi cameras with microphones even offer the burglars the opportunity to listen in. We recommend using wired cameras as they are not susceptible to WiFi hacking.


Cameras pointed indoors still need light, if you’re monitoring a warehouse you’ll need to light the area if you want to see the area. If the area’s dark you have the option of lighting the area or using Infrared.

Many cameras have built in infrared for night viewing. It sounds great but unfortunately the picture quality from infrared is quite poor. These cameras often have Infrared LEDs built into the camera head but these are almost always not bright enough to illuminate the area you need to see.Additional Infrared lights are needed to illuminate the area to get a better picture.

zoneminder_3Motion detection sentry lights

I’m sorry to say, but the best results for night vision are not achieved using Infrared. cheap garden variety motion detecting sentry lights can be configured to throw a 250 watt flood light over the area when they see movement, your cameras can then record a nice bright high quality image. If you want an even better quality image go for a camera such as the Panasonic BL-C1 with colour night vision and a set of sentry lights.


zoneminder_4Zoneminder is a free camera monitoring package that runs on most Linux distributions. It’s considered one of the best camera monitoring solutions out there with all of the features you would expect of a commercial package.

Zoneminder’s only drawback is that there is very little documentation available for it. Having said that if you understand how the web works and know a little about PHP you can make changes to the way that Zoneminder works. If you don’t you can still take advantage of some of the most sophisticated features.

We’ve put together a short list of some of Zoneminder’s more powerful features

  • Fully web based application
    Zoneminder is fully web based, all viewing and configuration can be done from the web browser. This makes remote viewing a snap, simply forward the zoneminder port through your ADSL modem and now you can see your cameras from anywhere.
  • Camera Support
    Zoneminder supports all common cameras available, but Linux might not, you’ll need to make sure that USB cameras and capture cards have driver support in fedora
  • Motion detection
    Zoneminder’s advanced motion detection lets you mark off parts of the image so that they do not trigger motion.
  • Motion capture
    Zoneminder will record events and send them to you as alerts via email or FTP
  • Timestamp
    Not a rocket science but a necessary feature for a security system

Operating System

zoneminder_5CentOS is a community port of the famous RedHat Enterprise Linux used across the globe. We recommend using CentOS or Fedora as it has a wide range of supported hardware which will help you when selecting USB or capture cards for use with your Zoneminder system

We recommend that you install Zoneminder on a Virtual Machine under VMware, ESXi, Hyper-V or KVM. You’ll have to install Zoneminder on your server natively if you plan to use composite cameras and a capture card because current Virtualisation does not support capture cards at this time.

If you’re not familar with Virtualisation, VMWare server allows you to run a copy of another operating system in a window on your desktop. The operating system running in the windows is completely oblivious to the fact it is not running natively on your hardware and will run and act like a normal computer.

Using Cacti to measure temperatures

TEMPerThese TEMPer USB Thermometers are cheap and easy to use. Amazon sell them for $24.99 + 2.99 shipping, so they’re great value.

The software included on disk is awful. I mean really really bad. So don’t bother with it. You will however, need the driver on there. The driver software I got was almost entirely in Chinese but once you run it you can see the install button and that’s all you need to click to install the driver.

Once the drivers are successfully installed I suggest unplugging and replugging just to confirm that all is well with the device itself.

The latest UTAC TEMPer software is available on Sourceforge

The UTAC software development was abandoned some time before the end of 2009 but the software is still the best available and contains all the features you’ll probably ever need.

Set the UTAC software up to use the XML web server to present an XML page containing the temperatures for the TEMPer sensor(s)

For this setup I don’t enable the HTTP web server option as the XML will give me all I need. If you want to get to the UTAC graph you can keep the web server enabled.

Remember to allow incoming connections to the XML web server in UTAC through your firewall otherwise you wont get any data.
I also recommend testing the XML server manually by going to http://<your ip address>:5050 and seeing if you get any output.

Some browsers (IE) will not display raw XML so if you get a blank screen that’s actually a good sign. You can usually select to view the source of a web page and you will see the XML there – otherwise use Firefox!
Here’s what the XML should look like if you have two thermometers running:

<timestamp0>03/07/2010 11:46:05</timestamp0>
<timestamp1>03/07/2010 11:46:06</timestamp1>

Next you’ll need to create a script file to get the XML page from the UTAC xml webserver and return the result to Cacti

I am running Cacti on Fedora 9 if you’re using a different distribution or version your setup may vary.

I’m not expert in perl so I just knocked up a quick shell script to do this. I’m working on building a super perl script that will do the work without having to save files to disk.

This file should be placed in /usr/share/cacti/scripts/ and I called it

wget -q -O /usr/share/cacti/scripts/temp/temper0.txt
grep temp0 /usr/share/cacti/scripts/temp/temper0.txt > /usr/share/cacti/scripts/temp/temp0.txt
sed -i 's/<temp0>//g' /usr/share/cacti/scripts/temp/temp0.txt
sed -i 's/</temp0>//g' /usr/share/cacti/scripts/temp/temp0.txt
cat /usr/share/cacti/scripts/temp/temp0.txt

To get sed the correct permissions to write to the cacti folder I had to make a temp folder under the cacti scripts folder and use chown to give rights to the cacti user.

You’ll need to make sure the script has execute permissions using chmod +x

Once again it’s best to test your script and make sure it works properly and has the right privileges. A quick way to test is to change to the cacti user (using su cacti) and run the script. If you receive any error messages you’ll need to tweak the permissions on the folder.

Kevin der Kinderen has created a nice guide for going from script to graph in Cacti. I followed his guide substituting my script for his random number generator script.

I have set up two thermometers as part of another project which are working well as you can see from the graphs below
cacti-temp1 cacti-temp2
Because of the cheap price of the units and the fact that the awesome UTAC software will read multiple devices I’m planning on ordering more for my servers too.

If you’re considering getting a few of these TEMPer USB Thermometers please note that they can be unreliable on long run USB cables so you’ll probably need active USB extension cables or powered hubs every few meters.

2015 Update

We have now ported all our thermometer monitoring to Raspberry Pi’s using the i2c interface. We’ll be preparing an article on this soon.