tailieunhanh - Apress - Smart Home Automation with Linux (2010)- P57

Apress - Smart Home Automation with Linux (2010)- P57:Linux users can now control their homes remotely! Are you a Linux user who has ever wanted to turn on the lights in your house, or open and close the curtains, while away on holiday? Want to be able to play the same music in every room, controlled from your laptop or mobile phone? Do you want to do these things without an expensive off-the-shelf kit | CHAPTER 7 CONTROL HUBS Figure 7-7. A simple network configuration This allows you to reuse the router as a network switch and employ servers with only one network port such as the majority of small low-power mini PCs on the market. If this configuration is too limiting such as when you want to use Linux as the router itself then you can adopt a configuration like the one shown in Figure 7-8. With this setup you will need two network cards and a separate network switch. Other machines and media head units connected through LAN NodeO - Linux Server Figure 7-8. Using a Linux server to separate the two network domains 263 CHAPTER 7 CONTROL HUBS In either case you use a remote server such as a colocated server or a virtual machine located in a data center to accept and process all traffic thereby hiding the identity of your home machine. NodeO Figure 7-9. Using an external server Wiring Looms Whole-house audio and video with media accessible in every room can happen in one of two primary ways. The first is by using small PCs in each room connected to the network to decode the audio locally. This is easier to upgrade and allows audio and video data to be streamed and controlled locally with very little effort. It is however expensive because of the hardware needed in each room. It is also inconvenient in those cases where you want to move between rooms while watching or listening since you have to manually restart The cheapest way of distributing AV data is by running cables to each room. This involves a combination of amplifiers and switchers as shown in Figure 7-10. 7 The software to manage this is currently minimal to nonexistent. 264 CHAPTER 7 CONTROL HUBS 1 DVD player VCR Games console etc. 1 Figure 7-10. A simple AV distribution network In all cases the generic term of AV is used to refer to audio and or video data according to your needs. You will notice that distribution among the rooms upstairs is easier since the cables can be run up into the attic across