tailieunhanh - Apress - Smart Home Automation with Linux (2010)- P7

Apress - Smart Home Automation with Linux (2010)- P7: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 1 APPLIANCE CONTROL back-EMF generates a large voltage spike that can blow the fuse in the AM12U if you re lucky or the device if you re unlucky . Figure 1-7. TheAM12U 52 x122 x33mm There is an in-wall version of this called the AW12U with a similar specification. Note You can often use these devices to automatically power-cycle routers and modems when the Internet connection is unavailable often from the router being choked or when it simply crashes. Appliance MicroModule AWM2 This is the same module featured previously and in Figure 1-6 as a suitable candidate for light control because it can also be used to control appliances. Apart from its smaller size 46 x46 x18mm its main benefit over the AM12U is that it has a much higher power rating making it possible to power fan heaters and their ilk. The given power specification on this unit is 2kW for incandescent lamps 3A for inductive appliances and 16A on resistive loads. 13 CHAPTER 1 APPLIANCE CONTROL As mentioned previously this device is mounted in wall outlets making it more difficult to circumvent. Consequently this module allows you to switch off a child s TV or stereo system at night without them simply unplugging it as they might with an AM12U. Table 1-1 gives a breakdown of the previously referenced devices. Table 1-1. Basic X10 Modules Appliance Name AM12U Appliance Module plug AWM2 Appliance MicroModule in wall LD11 DIN Rail Dimmer LM10U Wall Switch LM12U Lamp Module LM15EB Bayonet Lamp Module LM15ES Screw-in lamp module LWM1 MicroModule with dimmer LW12 In-wall module with dimmer like LWM1 but no two-way comms TMD4 MicroModule Transmitter Dimmer four-switch in-wall no power handler Internal Devices These devices are rare and usually fit in the novelty category. One good case is REX-10 a barking dog alarm system Upon receipt of a suitable X10 message for example from a motion detector this device plays the noise of a dog barking followed a few moments later by the sending of an X10 message to .