“..AUSTIN (KXAN) – Austin drivers making their morning commute were in for a surprise when two road signs on a busy stretch of road were taken over by hackers. The signs near the intersection of Lamar and Martin Luther King boulevards usually warn drivers about upcoming construction, but Monday morning they warned of “zombies ahead.”..
Source:Austin News KXAN“
Only time will tell. I hope Piet is ok.
I’ve posted this sort of picture before, it’s what my brother refers to as the “crap on a board” image. This time I’ve taken a second to mark some of the components so I can explain what is taking place in the “crap on a board” picture.
1. RF Modulator – This device takes a composite signal (such as that spit out by your DVD player or Gaming System) and converts it into a specific frequency range which corresponds with an accepted North American television channel.
2. The Composite signal feed. In this case it is the feed from the amplified output from the CCTV system Multiplexer.
3. The new modulated signal is sent back out on the frequency given to channel 75.
4. The Modulated signal is fed into a splitter turned backwards (now acting as a combiner).
5. Unmodified CATV signal is fed through a high/low pass filter which blocks the frequency range assigned to channels 71-78 (leaving them blank – any TV viewing this feed would see nothing but snow on these channels). When the “filtered” CATV feed is combined with the modulated feed a NEW channel 75 is inserted into the CATV signal.
6. CATV Amplifier – Simply takes the new feed and increases the gain somewhat ensuring that the various sets in the house (three different runs) have clear picture.
The end result? Switch on any television in the house and switch to channel 75 and you’ll see the perimeter of the house, nicely labeled and time stamped. There remains room in the 71-78 channel range to insert two more custom channels (anything could be added here).
Not bad, total cost of the modulator/filter/amplifier arrangement? Not counting the cost of the piece of wood approximately $90 CDN.
Pretty slick, huh?
There are a few critical elements to the computer I was seeking, it had to be fairly recent (2Ghz+/- processor speed), it needed a few Gig of memory (either present or at least capable of increase) and the storage needed to be fairly large (IDE 500Gig HD minimum).
The computer also needed to be capable of working with the Ebay 8 channel DVR card (sadly something I never know until it comes time to plug the damn thing in) and finally the computer needed to be inexpensive.
I may have acquired that computer yesterday. An HP Compaq Desktop, 2.8Ghz processor, 500Meg RAM (one slot used and one remaining open, SDRAM) and 40 Gig HD, along with onboard sound, NIC etc etc etc for $89.99 – A clean $100 after the gummint took their due).
The only problem with the PC appears to be the HP specific half height PCI slots, but thankfully the DVR card is half height, and it was a moments work with tin snips to get the card to fit with the case closed. Some quick exploring in Ubuntu and I confirmed that at least it was seeing 8 video devices (a good start), although all kinds of hardware detection errors kept threatening to rain on my parade.
In the end the card works fine. Up and running within a few hours. Higher resolution and frame rates chewed through 50% of the 40Gig drive in about 3 hours of experimentation (that was just one camera 640×480 at 25fps), upgrades are going to be imperative.
More experimentation with different distributions of Linux to see how much I can decrease the overhead without making the thing any more unfriendly than absolutely required.
Update: Satisfied that the DVR card works, I’m proceeding with upgrading both memory and storage, this requires some bargain shopping for DDR Ram and a 500Gig IDE drive so may take a bit of time. The good news is that experimentation with Linux doesn’t have to wait for the upgrades.
Never purchase experimental candies… the results are often precisely as you’d expect.
Two words… “Chocolate Skittles”
Bletch!
My current system relies on 4 channel PCI cards each based around a single Conexant BT878 chip. They advertise a rate of 30fps (frames per second) which decreases by 50% for each camera added, resulting in approximately 3.5fps if all four ports are used (these cards can be had on Ebay for $10 a piece, with shipping included).
The card acquired for the new DVR relies upon 8 separate Conexant BT878 chips and claims 240FPS (30 FPS per input), although this will need to be tested (truthfully 10-15fps would be more than adequate).
Image resolution at 640×480 is doable, although this is a problem for the computers processor not so much for the DVR card.
Increasing both the frame rate and resolution will have a significant impact on the computer (processor, memory and storage), and I’ll have to seek the most bang for my buck in these respects.
As with the existing system all but the multiplexed feed will be recorded on a “movement” detected basis, and while this will reduce (if properly configured) the storage space needed it will increase the demand on the processor and memory.
Obviously I’ll be shopping around looking at computers next.
The backbone of any surveillance system is the recording package, without it the cameras are useful only as long as a human operator is sitting there and watching them (and even then only if the operator is capable or willing to initiate the appropriate response when something is observed).
For older systems time lapse video tape was used, but this suffered from some serious weaknesses (not the least of which was the physical degradation of the media itself, and the fact that reviewing the tape was a time consuming and cumbersome proposition).
Digital video recording offers longer recording times, no “worn media” issues and when combined with the appropriate software allows operators to scan through “event logs” looking for activity instead of reviewing tape on an almost 1:1 basis).
While Digital Video Recorders for surveillance systems are appreciably less expensive than even a few short years ago they can represent the single largest expense in a “budget” or hobby system.
I’ve decided that I need to increase the capacity of the system in use for my home, and have decided that this will require me assembling a new system rather that upgrading the old one (for a number of reasons, not the least of which is that upgrading the old system would take the recorder offline while it was reconfigured, and this way there’s no pressure to hurry things along.).
Commercial multi-input DVRs are available for between $900-$5000 and offer a dazzling array of options. For the purposes of this project we are going to stick with a fairly basic system comprised of a Personal Computer running Linux, free software (“Free” as in open source, not “free” as in pirated) beefed up RAM, processor and storage space and a DVR card capable of monitoring at least eight cameras).
The goal is to keep the footprint of the entire package as small as possible (so no HUGE tower desktops for this one), and to see if we can’t get a nice slick “custom” appearance into the deal.
We’ll be aiming to bring the entire system in under $400 (CDN) with the parts accumulated over time to spread out the up-front costs.
I tend to view New Years Resolutions as a sort of high profile half hearted attempt to change things in our lives (if these things really mattered, would we wait for the 1st of the new year to get on with them?). I have a list, but it has not sprung into existence overnight.
That’s just off the top of my list, it does go on at some length I’m afraid.
What are you working on changing? Not just the flat resolutions “Eat healthier, exercise more, quit heroin…” but the real changes you’d like to make.