Household Appliances Remote Intelligent Control System

Home intelligent system appears in the later 1970's. In the middle of 1980's, home intelligent controller has come into being in western market. In January 1984, the first intelligent building was being put to use in America. Since then, intelligent building springs up in a lot of countries. At the same time, family and building intelligence also become the inevitable tendency of meeting the needs of people's living standard and life quality. Various family control systems have emerged as condition requires. Our country start much later in this field, so the urgent task is to develop our own home intelligent control system which can implement the basic functions as well as can fit the present condition of our country.Home intelligent control system has characteristics as follow: (1) network have the ability to communicate with network;(2) digitlization make max use of digital technology;(3) intelligentization have the ability to memory and self-dispose in respect to control function.The major function of family intelligent control system includes family safety alarm, telephone long-range control and infrared concentrating remote control as well as automatic watch control etc. Group network mode divides into two kinds: Wired group net and wireless group net. Wired group net is to organize net mainly using power line or the telephone line at home; while the major technology of wireless group net is to use Home Reflect Frequency (HomeRF) technology, Bluetooth technology and HomePAN technique etc.This paper is to design a system, using power line and telephone line to organize net, adopting DTMF (Dual Tone Multi-Frequency) decode chip MT8880 and power line modem chip ST7536, to unify all electrical equipment and safety alarm sensor at home into one network so as to realize the two-way function aslong-range intelligent control and automatic alarm of electric appliance.The major content of this paper includes some following aspects: First, introduces DTMF coding technique and power line carrier technology.Chapter three shows the overall structural block diagram and working principle of the system as well as explains the structure and function of every part. Ringing detection circuit accounts for detection of ringing signals. Imitational telephone hang up/on circuit realizes imitational telephone hang on/up. DTMF coding circuit completes DTMF's coding and decoding and signal sound detection. Sound hint circuit introduces into automatic sound hint, making system's interface much more friendly. As the core part of this system, SCM (Single Chip Micyoco) realizes the intelligentization of the system. The interface circuit of ST7536 and power line finishes the modulation and demodulation of digital signal. To prevent program from entering " dead circulation ", making system out of control, this system adopts watchdog technique. This system also includes memories used to store program and the telephone number that will be dialed.Chapter four explains the manufacture of PCB (Printed Circuited Board) and measurements taken to prevent disturbance when making PCB.Chapter five illustrates partial block diagram in respect to the software of this system.This system has a simple design, low cost, and flexible organization. And the control scope can be big as well as be small.