Design and application of mobile network control s

Design and application of network control system for smart home

the so-called smart home refers to a new type of residence that uses assistant generic cabling to comprehensively configure the system through various functions in the residential area, and uses computer network to implement automatic management of various equipment in the residence. In China, with the rapid underwater improvement of the national economy, especially the rapid development of modern science and technology, high-tech products have changed people's living habits, improved people's quality of life, promoted the modernization of family life, comfortable and safe living environment, and people's demand for personalized smart home is gradually increasing. The construction of smart home in China is developing rapidly, and some houses with certain intelligent management functions have been established. This paper introduces a network control system of smart home

1 system scheme design

the home smart home system described in this paper adopts communication, which consists of two single-chip computers in series to form the core of the control host, and uses power line carrier communication as the bottom communication network of the home. The real-time monitoring system of household electrical facilities composed of this has incomparable advantages. This design concept has also been applied to the management of smart buildings and smart communities

the user sends voice control instructions to the G SM (Global System for mobile communications) module in the host of the residential control system through mobile (GSM communication) or fixed (voice communication) outdoors. After receiving the user's instructions and processing them by the single chip microcomputer, the user communicates with each controlled extension through the power line carrier communication (PLCC) module, According to the instructions sent by the host, the extension will call and feed the working state of each controlled facility in the house to the host, and then the host will feed back the working state of the controlled facility to the call user through the GSM module. Then the user will send control instructions to the host of the control system through the callback signal according to the feedback of the voice prompt, and the host will command the extension to control the working state of each controlled facility accordingly, In this way, users can understand and control the working state of residential facilities, as shown in Figure L

1.1 microprocessor

the smart home control system uses dual single-chip microcomputer MCU (micro control unit L) and MCU (micro controlunit 2) to realize the remote monitoring and operation function of electrical facilities in the home system, and solves the contradiction between measurement and control and monitoring and information feedback, so as to improve the real-time performance and effect stability of the system, and the price is relatively economic

two microcontrollers in the host of the control system are connected in series. Mcul sends and receives relevant information to the user through the GSM module through the voice module, and the tires with medium or upper ranking may become the preferred product of the buyer. The man-machine dialogue will feed back the working state of the control system, and the user will send instructions through the GSM module according to the feedback, instructing the control system to make the household electrical control facilities make corresponding control actions; MCU MCU makes corresponding control to transmit data to MCU 2. MCU first sends interrupt command to MCU 2 to make it enter the interrupt state, and then MCU sends the data serially to MCU 2. MCU 2 is connected with liquid crystal display (LCD) to display the working state of the control system, and the keyboard connected to MCU 2 is used for users to input relevant control commands in real time. In this way, when the host of the control system answers the user's incoming calls and instructions, it can execute relevant instructions or key control at the same time

1.2 control command transceiver module

by the hand GSM network system, it has anti-theft copy ability, large network capacity, rich number resources, clear calls, strong stability, not easy to be disturbed, sensitive information, few dead corners of calls, low power consumption and other application characteristics, which greatly facilitates the user's real-time monitoring of smart home. The GSM module of the host of the control system adopts the TC35 module of Siemens company. The baseband processor, the core component of this module, mainly processes voice and data signals in the GSM terminal, and covers all analog and digital functions in the cellular RF equipment. TC35 module white tape RS232 communication interface can easily communicate with PC and single chip microcomputer, and realize data, voice transmission, message service and fax in the system scheme quickly, safely and reliably

1.3 dual tone multi frequency communication

the key functional component used in the dual tone multi frequency DTMF (dual tone multi frequency) circuit is the MT8870 decoding chip, which receives the dual tone multi frequency analog signal received by the GSM module in the control host and sent by the user. It aims to filter the high-frequency and low-frequency components of the signal first through the dual tone filter, and then through the high group filter and the low group filter respectively, After analog-to-digital conversion, the two components are sent to the digital detection and calculation circuit to generate 4-bit binary data composed of 4 high-frequency signals and 4 low-frequency signals, which are read by the microprocessor MCU from the data bus port to complete the collection of dual tone multi frequency signals. The digital detection and calculation circuit in the chip further optimizes the audio signal to prevent MCU from receiving the wrong signal

1.4 voice module

the voice module circuit in the host of smart home control system is mainly composed of MCU MCU, ISD4004 voice chip and LM386 power amplifier. The voice module is mainly used to receive and latch the serial data stream from the control circuit, complete the address code search, recording and playback, and provide audio current to the audio amplification circuit. The voice prompt, response and query functions to be realized by the control system are completed by the communication between MCU and ISD4004. ISD4004 voice chip sends operation commands through the built-in serial peripheral interface SPI (serialperipheral interface) of MCU MCU. It uses multi-level direct analog storage technology to store the amplified input voice information in a form close to the original analog. During playback, the input analog voltage is sequentially read out from the storage array under the control of the sampling clock. The smoothing filter on the output channel removes the frequency component and restores it to the original sampling waveform, which is amplified by the LM386 power amplifier, and then coupled to the GSM module through the transformer to send it to the user or receive the analog instructions sent by the user, so as to realize the man-machine dialogue with the user, or drive the loudspeaker configured by the control system to pronounce

1.5 power line carrier

power line carrier communication (PLCC) is a unique basic communication mode of power system. It refers to the use of existing low-voltage power lines to load analog or digital signals such as data, voice, image, etc. into the hand power line through the power line modulator in the form of carrier for high-speed transmission, and then the modem (commonly known as power cat) that receives information demodulates the signal from the current, And transmitted to the terminal equipment to realize the technology of information transmission. Using PLCC communication technology has the characteristics of stable and reliable information transmission, reasonable routing, multiplexing signals at the same time, no need to invest in laying control lines, and changing the power socket in the original room into an information socket. Combining the power line communication technology, network and microcontroller, integrating the functions of power line and signal line, and connecting the microcontroller and home appliance facilities distributed in all corners of the house into a network is the most realistic and economic way to promote home automation on the basis of the use of the existing residential electric anchor fatigue testing machine and the functional characteristics of the equipment, which force line wiring

the power line carrier terminal carries out serial communication with MCU 2 in the host, receives control instructions and feeds back the working state of the control object to the host. The module integrates all carrier transceiver circuits. In order to realize the communication with the controlled object, it only needs to externally connect the supporting pin closing wire circumference and isolation high-voltage capacitor to form a complete power carrier application system, that is, the control signal sent by MCU 2 is modulated to 220V power line and the feedback signal on the power line is demodulated and transmitted to MCU 2

on each power line carrier terminal, there is an enhanced 8-bit processor built in. Its core is a multi-level pipeline instruction architecture MCU compatible with 51 instruction sets. At the same time, it provides in system programming ability for program memory, which is convenient for developers to repeatedly program and debug. Each terminal is also embedded with an LCD drive circuit that displays the working state of each terminal control facility. The terminal module is embedded with a carrier anti-collision mechanism, allowing multiple carrier devices to send and receive data at the same time. It is this kind of large-scale integration module that makes the control system have the advantages of low cost, low power consumption, multi-function, high reliability and other traditional systems

2 system design application example

2.1 fluorescent lamp dimming module

fluorescent lamp dimming module is composed of irs2530d and peripheral circuits, which integrates dimming control and half bridge drive circuit, significantly simplifies the design of fluorescent lamp dimmable ballast circuit and improves its performance and its performance. Irs2530d adopts IR's patented electronic ballast technology and high-voltage integrated circuit technology to ensure complete functions. The DC dimming input voltage reference is superimposed with the AC lamp current feedback signal, and the single pin dimming control is realized by the half bridge driver, which makes the electric ballast circuit work reliably and shortens the design cycle of the electric ballast

2.2 smoke alarm

smoke alarm uses the principle that particles in smoke refract infrared light. The circuit is mainly composed of infrared generating part and receiving part. In the state of no smoke, the sensor only receives very weak infrared light. When there is smoke infrared light entering the optical maze, the intelligent alarm circuit judges that once it exceeds the set threshold, it will send an alarm. The alarm is particularly sensitive to the visible smoke produced by slow smoldering or open burning. The photoelectric smoke alarm module only saw the laboratory report as mentioned above; Another problem is the price. The infrared photoelectric sensor can be reset automatically, and the ASIC can give an audible and visual alarm at the same time

2.3 pyroelectric anti-theft alarm

the key component of the anti-theft alarm is a pyroelectric module. When people or other targets with infrared characteristics enter their sensing range, pyroelectric automatic sensing will send out an alarm; When a person leaves the sensing range, the alarm will stop after automatic delay. After jumper selection, there are two trigger modes: non repeatable trigger and repeatable trigger. The pyroelectric module has photosensitive control and temperature compensation functions to avoid false alarms within the range of abnormal changes in environmental conditions. The pyroelectric module has an induction blocking time. When the induction module outputs each induction, it can immediately set a blocking time period. During this time period, the sensor does not accept any induction signal. This function can effectively suppress all kinds of interference generated in the process of load switching

3 conclusion

the smart home system described in this paper won the "first prize of the undergraduate comprehensive group for the selection of 2010 Chinese college students' electronic information practical and innovative works" in the activity of participating in the "third national electronic information practical teaching seminar"

the smart home control system described in this paper uses communication and dual single-chip microcomputer harmonic control to realize the process control and working state monitoring functions of the home system, which solves the contradiction between monitoring and control, monitoring and information feedback, and can make it synchronized to adapt to people's habits of use; PLCC technology is applied to effectively use the existing low-voltage power line as the physical medium to connect the microcontrollers and household appliances distributed in all corners of the house into a control system network; Compared with the existing smart home control system with the same function, the application scope of this design can be expanded, including alarm detection, intelligent processing and control