Power over Ethernet (PoE) is a technology that allows you to power a device over a standard Ethernet cable. This can be extremely useful in the IP camera world as it allows you to run one cable (Cat5) which will supply the video (data) and power that the camera requires to operate. This technology is not only good for IP cameras but can be used for VoIP phones, network switches, access points and EMBEDDED COMPUTERS.

Embedded computers, PoE can power a computer?

The IEEE 802.3at-2009 PoE standard, also known as PoE+ or PoE plus provides up to 25.5 Watts of power. Some manufacturers believe they can get as much as 51 Watts from the new standard.
This amount of power has led to the introduction of low power/low consumption computing devices. One example is the Avantech UBiQ-480.

The UbiQ-480 is a smart wall-mount touch terminal for eHome/Building. Multimedia and entertainment are main features of UbiQ-480 because of built-in powerful FreeScale i.MX31 CPU and Microsoft Windows® CE 5.0. Touch screen and 7″ 16 : 9 true color TFT LCD let the interaction between life and UbiQ-480 become more natural and colorful.

The system specs are slightly higher than a decent PDA however this is just the start of things to come for PoE. Critics of the technology say that PoE just doesn’t pack the punch they expected when the new standard came out. (What did they expect?) In time PoE will be able to power most devices around the home. For now it is perfect for your Home IP surveillance systems.

The Sentry Project is what got me started on Automated Sentries. I stumbled across The Sentry Project’s website and found their software and mount. It was at this point that i knew i wanted to build one of my own. I also knew i didn’t have the skills to code something like this from scratch, so i decided to purchase a copy.

Fortunately we were able to get David from The Sentry Project to answer a few questions about his project.

DB: The sentry project – Who came up with the idea for the project, and when did it begin? What was your inspiration?
David: It began in February 2008. Video games were the inspiration. Tribes, Perfect dark, Aliens, etc.

DB: Was it always intended for a paintball platform, or did it start with something else in mind?
David: The only reason I used paintball guns is because they show up better in videos. That’s it. Airsoft is a hell of a lot more convenient, more realistic looking and less expensive. Ironically people don’t always understand that you can put whatever non-lethal gun you want on there. They keep thinking it’s only for paintball or only for airsoft.

DB: Where do you see The Sentry Project going in the future? Do you have any other projects on the go?
David: I’m finishing up an auto tracking camera that will automatically track and zoom in on targets while recording them. When they are finished I will be the cheapest solution for these types of systems by far. My competition’s units are several thousand dollars and up for the same thing with the same features. Anyone who has tried to make out faces and license plates from regular security cameras will quickly see the benefits of an autonomous PTZ system.

DB: How is the auto-rake going? sold any? (had to ask…..)
David: That was just for fun.

DB: Have you thought of upgrading any of the components in the current build? (ie firewire camera, usb servo controller?)
David: I’m well aware of the other options out there.

DB: Have you had any of your customers build anything you were extremely impressed by? Or horrified by?
David: Nothing they could build would horrify me. It’s always fun to see what they’ve built. I’m always impressed when they’ve done it all with little to no help from me.

DB: Are you the sole coder for your project, or do you work in a team?
David: Sole developer.

DB: Has the sentry had any press coverage? (ie magazines, tv, pb comps)
David: Yea, one of the videos (#8) was on TV without my knowledge. That’s partially why it has so many views. I’ve never tried to get it into pb magazines. Traffic from the internet has been more than enough. I have a hard enough time keeping them in stock as it is.

I would like to thank David for answering these questions. If you would like to check out his products then check out the banner on the right “The Sentry Project”

It was pretty good weather today, so i decided to get the water sentry out and give it another test. I’ve put the video together below.
Things to note:
1. Keep an eye out for the green laser, it is hard to see. I’ll get a HD camera soon to capture all the small things.
2. During the video, the Picture-in-picture of the actual sentry is not in sync with the video. I took about 40 minutes of video all up and really couldn’t be bothered finding the correct spot to sync it up…….again, sorry.

I’ve also modified the nozzle from the original. I’m using a sprinkler extender for the nozzle and some step-down connectors to attach 6mm hose. This created a fair bit more pressure in the line and extended the range of the water. (It is still maxing out at about 8m)

After recording the video, Dave mentioned that the frame rate for the webcam was way to low. I was getting only 4-5 Frames Per Second. I wasn’t entirely sure what the problem was however like all computer hardware, the driver was my first point for fault finding.

Sure enough, the stock standard XP drivers were running the Logitec quickcam pro 9000 at a substandard configuration. The Logitec website had a driver package for the webcam and that sorted it out. I also noticed after installing the proper drivers that i had a few extra resolution settings within the sentry software.

The correct drivers brought the frame rate up to approx 20 FPS. This is a huge improvement compared to 4 FPS.

So what did i learn from this? Never use the standard XP drivers.

This is a video of the first trial. I was playing with the calibration and the cat decided it wanted a piece of the Hexapod and the laser. The sentry manages to successfully track both targets. If you keen an eye out for the the red laser you can see it tracking back and forward between the two.

The water sentry is not a unique idea. Dave over at thesentryproject.com got me started with his initial build up. I guess this was my first build due to the fact that air-soft and BB guns are illegal in Australia, and the idea of getting a paintball gun seemed a little ambitious for a starter project.

I managed to find a commercial security camera housing at work that was going to be thrown away, this was to be the basis of the build. I also borrowed a camera stand for the base. (This has proven to be a little unstable for the camera housing, so I’m  trying to source a surveying tripod) Inside the camera housing I’ve mounted the servo controller, the logitec 9000 webcam, the Battle switch and a power-board. Mounting it all was relatively easy as there was a universal type mount inside that was plastic and i could drill spacers into it easily. The serial cable, usb cable for the webcam and servo extension leads all run out through a hole in the bottom of the camera housing. When i get time i think i will use proper waterproof plugs so that water ingress is not a problem. However the chance of water coming up from underneath is next to nothing.

Once everything was mounted i needed power for the electric water valve. This water valve is a standard solenoid valve that you can buy at any home hardware store (In my case, Bunnings) The electric water valve is designed to be opened and closed as power is applied to it. It is exactly the same as you would use in garden irrigation systems. The hardest part was hooking the power up for the solenoid to the battleswitch. A Standard 24v transformer is used, however the problem here is that you now need 240v/110v power to your sentry. Once this is sorted the sentry-project software will be able to activate the battleswitch which will power the solenoid on/off.

Ok so the X and Y axis servos were hooked up to the servo controller and the battleswitch was also hooked up to control the trigger.

I use a 6v R/C battery pack to power both the servos and the servo controller. Since i have put a powerboard inside the camera housing i shall buy a 6v power supply and use that. This will allow the water sentry to run 24/7 if i wish. However for now the 6v battery pack will do.

That’s it for the build up. Nothing special, the hardest part is setting up the battleswitch and making sure the mount is nice and sturdy. If  it wobbles around the webcam may pick up false targets and not work as well as it should.

Configuring the software was definatley a learning curb, just getting used to the process for calibration and what different settings do took a little bit of time. The ‘Hexapod vs The  Cat’ video is the first time i really got to play with the settings and see how it worked. Check it out HERE if your interested.

What the future holds for version 1:

I need to find a mount that is sturdy. The camera stand just didn’t cut it. Dave at thesentryproject.com utilises a surveyor tripod and that seems very sturdy. Just make sure you get one with a flat top on it not a dome top. May be a bit hard to mount to the dome top.

Power for the sentry is also something i want to fix. As I’ve already said, i need to find a 6v power supply that will power the servos and the servo controller. Dick smith should be able to sort me out here.