I debated long and hard with myself (as I tend to do) on whether to build my own CCTV system or to buy one. Of course, I would buy the cameras, but would it be better to buy a Digital Video Recorder (DVR) or to build your own Linux box to accomplish the same thing? There are good open-source software solutions out there, like ZoneMinder, which allow you to build your own DVR with relative ease. Certainly, it sounded like fun and a good learning experience.
I spent some time looking around at what was available on the market, from multi-channel frame grabber boards to off-the-shelf DVR boxes. I had quite a bit of trouble determining an appropriate hardware configuration, ensuring that the right Linux device drivers were available, etc. The more time I spent on deciding which hardware to buy, the more I realized that assembling and maintaining a good, reliable DVR system would take a bit longer time than I had expected. In addition, I decided that since this is a surveillance system, it has to stay up no matter what. It needed to be rugged, reliable and low power (so it could run off a car battery for a significant length of time). It also had to have programmable digital outputs so I could connect it to another alarm system, and it had to have a good Ethernet interface so I could program and access it remotely.
In the end, I decided to buy an off-the-shelf DVR box. The low cost and good functionality of something like the Rover Systems 4-channel DVR was just too good to pass up. The Rover box had all of the functionality I needed, plus it cost less than $200 and drew less than 40W. It was a plug-and-play solution so I could move on and spend more time with the rest of the house systems. The user interface was great – I could program motion sense areas with a mouse, and I could even download video off the hard disk via the built-in web interface.
On the front there are the usual buttons to select which view you want to see on the external monitor (all 4 cameras or only 1), as well as control buttons for the DVR (record, play, search, etc). In addition, there are menu control buttons and a USB port. The rear of the box has 4 BNC camera inputs, as well as a BNC monitor output, audio in/out, an Ethernet port and a screw terminal for RS-485, alarm in and relay output. There is also a USB port for a mouse, for use when programming the DVR locally.
In addition to the DVR, I also got myself 4 nice little CCTV cameras. I got them inexpensively at Hua Qiang Bei in Shenzhen, my favorite place in the world to buy DIY electronics, where I paid less than 1/3 of what they cost in the Philippines. I got the shopkeeper to swap out the standard lenses for 6.5mm wide-angle lenses, and the cameras are also equipped with IR LED’s for true night-vision.
The cameras came with mounting brackets, but I also got a local machine shop to make for me custom steel poles so that I could raise 3 of the cameras up off the perimeter walls. The red color of the rust-proofing doesn’t look too presentable though, so I’ll need to paint them white before installing them. More on this next time!
