Design of Intelligent Alarm System Based on GSM Network Shun Qing XU

Transcription

1 Applied Mechanics and Materials Online: ISSN: , Vols , pp doi: / Trans Tech Publications, Switzerland Design of Intelligent Alarm System Based on GSM Network Shun Qing XU Department of Electrical Engineering,Yancheng Institute of Technology, Jiangsu ,China Key words: GSM Network; RMON; Burglar Alarm Abstract: For the feature that the alarm system of home, industrial site security and anti-high temperature was limited by lines, we constructed an intelligent alarm system based on the GSM network to realize the wireless remote detection and control by sending and receiving messages via the GSM network technology. Practice has proved that the system has a wide application prospect with low misinformation rate, simple operation and higher cost-effectiveness. Overview Traditional smart home system generally conducts a variety of control and communication by wire, which brought a lot of inconvenience to the installation and maintenance of monitoring equipment. What is more, the scalability of the system performance is very poor because it depends excessively on the physical connection between the control room and the remote site. The development of modern mobile communication technology, allows people to change the current situation. No matter WCDMA or TD-SCDMA, Mobile Communications provide us a higher-speed wireless data application full of variety. Short Message Service (SMS), as a basic GSM network business, is more and more applied by because of simple connection, inexpensive cost, a wide range covering and easy implementation. The alarm system designed in this paper is based on the point-to-point short message service on the mobile platform, and it connects the mobile communications and the alarm function well. Architecture of the System The smart home alarm system connects the mobile communications and the alarm function using point-to-point short message service on GSM mobile platforms. When the emergency situation appears, the alarm signal will be sent by the system via SMS, so that it can follow the user at any time, and show the emergency information to users who at not at home in time. When the user receives the SMS, they reply the SMS to the alarm system, and the alarm system will perform the appropriate actions. Smart home alarm system will not only be able to make up for the deficiencies of the traditional alarm system, to overcome the its disadvantages such as the nuisance noise nuisance, limited alarm scope and low effectiveness, but also a development and utilization of value-added services in mobile communication system. In the system,the sensor will send the collected signal to the microcontroller, and the microcontroller sends the control commands to the mobile communication module after the judgment, communication module will call the predesigned command alarm after receiving SMS and send the information to the user's mobile phone and PC using GSM network, which achieves the alarm function. The user will reply the SMS to the alarm system after receiving the alarm SMS. The system will control the executive module to implement appropriate measures by judging the user replies to the text message content. Microcontroller in the system, as the control center, is equipped with information collection module, communication module, displaying module, alarm module, and the implementation modules. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, (ID: , Pennsylvania State University, University Park, USA-12/05/16,02:36:07)

2 Applied Mechanics and Materials Vols Design of system hardware In Smart home alarm system based on GSM network, the microcontroller can real-time detect the changes in the sensor. When the sensor changes, the corresponding signal of the microcontroller will be compiled into a form of text message and be sent to the TC35i module. And the then it will be passed through the module to the phone. The users can edit the fixed format information on the phone and send it to TC35i module. The microcontroller will read the corresponding information in the module, decompose the information, and then extract control function signal, and then control correspondingly. The system has the following main functional circuits: signal detection circuit, microcontroller, LCD circuit GSM communication circuit, as well as alarm and control the implementation of the circuit. The system hardware schematic diagram is shown in Figure 1: Fig1 The hardware configuration diagram of the system Data Acquisition Module.For the security purpose, the system monitors the temperature of the house and the human body motion. We select DS18B20 digital temperature sensor as temperature measure components. DS1820 is DALLAS Semiconductor Company's latest improved temperature sensor after their DS1820. Compared with the conventional thermistor, they can directly read out the measured temperature, and achieve the 9 to 12 digits reading method after a simple program according to actual requirements. It can read 9 and 12 digits separately in 93.75ms and 750ms. Reading and writing on DS18B20 only need one interface line. Temperature transforms the power derived from the data bus, and the bus itself can also supply power to the attached DS18B20, without the need for additional power. Body motion detection is handled using HC-SR501 infrared detection module. HC-SR501 use of original German imports LHI778, probe design, which has a high sensitivity, reliability, and the ultra-low-voltage operation mode and be widely used in all types of auto-sensing electrical equipment. Design of communication module.the system uses the Siemens industrial GSM module TC35 to send and receive SMS. TC35 is an industrial grade GSM module support Chinese short message, working in EGSM900 and GSM1800 dual band. The module has AT command set interfaces, which can support SMS of text and PDU mode. The TC35's data input / output interface is actually a serial asynchronous transceiver in accordance with ITU-TRS232 interface standard. It has fixed parameters as follows: 8 data bits and 1 stop bit, no parity, the baud rate is selectable between 300bps and 115kbps with a default value of We use RTSO / CTSO as the hardware handshake signal, XON / XOFF and CMOS level to control the software flow, which support the standard AT command set. Through this interface AT commands can switch the operating mode such as voice, data, SMS and fax mode. According to the pins and working principle of TC35, the

3 1580 Mechatronics, Robotics and Automation design of its peripheral circuit mainly consists of the start circuit, a power circuit, external SIM card circuitry and data communications circuitry. In order to provide a voltage of 3.3V to TC35, a voltage conversion circuit is designed to convert 5V to 3.3V. REG regulator chip whose input voltage ranges from 4.75V to 12V and output is 3.3V is used here. The TC35 integrated a SIM interface compatible with the ISO IC Card Standard. In order to fit the external SIM interface, the interface is connected to the main interface (ZIF connector). TC35 reserves 6 pins for the SIM card on the ZIF connector, in which the CCIN pin is used to detect whether the SIM card is inserted in the SIM card holder. When the SIM card inserted, this pin is set high, the system could work properly. The data communication circuit mainly completes the functions of sending and receiving short messages, communicating with SCM and PC and controlling software flow. The TC35 data interface is a serial asynchronous transceiver, working in the CMOS level. The data communication circuit uses the MAX232 chip from Maxim as the core to realize the level conversion and serial communication. That is to say, the TC35's RXDO / TXDO port is connected with the microcontroller and PC by MAX232. The communication protocol is the AT command set. Design of the software of the system After the start of the system, initialization will be taken first of all. It mainly comprises serial port initialization, LCD initialization, sensor initialization and TC35 module initialization. Then it will enter the loop check status: measure and display of temperature, detect whether the alarm signal is triggered. When the alarm signal has been detected, the system will call the subroutine of sending SMS to send the predefined alarm SMS to the mobile phone users and the host computer. The system will perform the appropriate action based on the user's response, and then send OK SMS to the mobile phone users. If there is no alarm signal triggered, the system will wait for the command to receive short messages. When a short message format-compliant has been received, appropriate operating will be taken by the system based on the content of the short message. Then the corresponding SMS tips will be sent to the mobile phone users. Design of communication module program.at command plays an important role in TC35 communication. Many actions of TC35 can be controlled by AT commands, including dialed number, key control, Fax and GPRS. 1.Receiving and judgment of SMS In order to receive an SMS smoothly in the use of GSM module, initial parameters of the TC35 should be set as follows: 1) "AT & F" command should be sent from the microcontroller to the TC35 to initialize the system."ok" command will be returned when initializing successfully. 2) Send AT + CMGF = 1 "command to set the format of the short message to be text, then the" OK "command will be returned. 3) Send AT + CREG? "Command to query TC35 network registration. If the registration is successful, "OK" will be returned. So this module can successfully receive text messages and save them into the memory of the SIM card. Then the microcontroller will cycle sending "AT + CMGR = 1" command to read the first SMS in the memory.

4 Applied Mechanics and Materials Vols Alarm system takes the judgment of the data of the short message received mainly by the method of value comparison. When the system receives a SMS from mobile phone users, judgment of the content of the short message will be taken. The system will react based on the results of the judgment and send the corresponding SMS to the mobile phone users and the host computer. 2. Sending short messages The sending process of short messages is as follows: 1) First of all, a command should be sent from the microcontroller to TC35 through the serial port to set the local short message service center address. Upon inquiry we can know the local SMS center number: Therefore, the command "AT + CSCA = " should be sent afterward. If the setting is successful, "OK" will be returned. 2) Then send the command to set the destination user's mobile phone address: AT + CMGS = 18,762,650,873 ". If the setting is successful, "OK" will be returned. 3) Select the appropriate content of messages according to the previous operation of the system: when getting successful implementation of a setting, the reply SMS content will be 'I AM OK'; when the temperature needs to read, the contents will be the scene temperature at the time. In addition, when the burglar alarm is triggered "Alarm" will be sent. When over-temperature alarm is triggered, the SMS will be "Over-temperature". After the message sending successfully, the "+" or carriage return will be returned. 4) Then send the command to set the destination PC's mobile phone address: AT + CMGS = 18,762,650,873 ". If the setting is successful, "OK" will be returned. The system needs to have the function of sending short messages to mobile phone users and the host computer at the same time. That is to say, continuous transmission of two short messages with the same content is required here. In order to achieve this, the program set flag x as the number of transmissions. The value of x should be judged before sending messages. If it is 1, set it to be 0, and then fill in the number of mobile phone users. If it is 0, set it to be 1, and then fill in the number of PC. Design of PC software.we use VB 6.0 to design and program the interface of PC software. Parameters that can help software to realize the serial communication are as follows: the set of serial number, baud rate, data bits, stop bits and parity bit; real-time display of serial data; contents and time based on the received SMS; reaction to the alarm signal. We use MSComm to realize serial communication. The main attribute initialization settings are as follows: MSComm1.CommPort = Right (Combo1.Text, 1) 'Set the communication port number as the item selected by Combo1 MSComm1.Settings = Combo2.Text &", n, 8,1" 'Set the serial port parameters MSComm1.InputMode = 0 'Receive text data MSComm1.PortOpen = True 'Open the communication port If the system detects that someone entered, it will send the burglar alarm SMS and alarm at the scene, when the anti-theft feature is turned on. When mobile phone or PC sends SMS "1" to reset the burglar alarm, the system will reply "I AM OK" short message. Conclusion The wireless GSM network smart alarm home system sends the on-site detection signal to mobile phones and surveillance systems via the GSM network, which implements intelligent alarm and control. With the continuous development of the national economy and the progress of science

5 1582 Mechatronics, Robotics and Automation and technology, the theory and practice value of using mobile communication technology to achieve remote control is increasingly evident. GSM-based system is suitable for a very wide range, and can meet the requirements of different positions. After testing, the system has good data transfer effect, and has a good anti-jamming capability. References [1] Su Weijia, Zhang Qiyang. Design of GSM wireless data acquisition system based TC35I [J]. Application of Electronic Technique.2009 [2] Zhou Qi.Visual Basic program design case tutorial [M].Beijing:Tsinghua University Press [3] Liu Changzhen.Design of GSM-based remote home monitoring and alarm system [J].Security Technology.2008

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