Abstract: Intelligent Systems Introduces the Basic principles of Wireless Systems, Block Diagram, detailed Description of the receiving method of telephone Network; Discussed pyroelectric infrared Sensors, Voice and other Circuit, given some of the Basic Circuit and Software processes.
Keywords: Wireless Burglar Alarm pyroelectric infrared Sensor
With the Promotion of the national Intelligence community Building, anti-Theft System has become the Intelligent Community of the necessary Equipment. In this Paper, SCM Control Technology and Wireless Network Technology, to Develop a Smart Wireless Networking Capabilities with anti-Theft System, and the Development of related Sensors. Wireless Data Transmission, without Re-Wiring, in particular, has been decorated for the occasion Inconvenient for users and Wiring.

1 Intelligent basic principles of wireless systems
Intelligent Wireless Security System consists of Sensors, Smart Home Alarm, Alarm Host of property and the related Management Center Control and Management Software. Figure 1 is a Block Diagram of Smart Home Alarm System, Figure 2 shows the Block Diagram of Property Management Center Alarm Host .
1.1 host circuit
Shown in Figure 1, the host circuit transmission by the RF receiver module receives the shock of the alarm signal device sent through the decoder (PT2272) decoded by the address of the alarm sensors and sensor data types, and address only the host can be host to receive the same. The figures represent the Decoder output type of Sensor Signal output into the CPU Li Solution of INT1, an interrupt handler. Interrupt handler through the DTMF Transceiver Circuit, make a Good User pre-SET Phone Numbers (such as Phone number , Office number) for Dial-up Remote Alarm; the same Time, Start the Voice Circuit, the pre-recorded through the telephone line Voice Signal to My master, to Achieve Voice prompt Communications. CPU Trigger Signal Siren output, amplified by the Siren or Horn Push, to Ward off thieves and Earthquake threats. Users can also remotely through the telephone line SET up / Deployment, and Remote Control through the Control of Signal output INPUT 8 Electrical Control Equipment Wired Connection, but also by encoding the Control Circuit and Wireless RF Transmitter module Connection of Electrical Equipment. Show some use RT12232A dot Matrix LCD module, character display; display the Alarm Time and Alarm types. Password CHANGE can be Achieved Keyboard, Voice INPUT and Information viewing.

Property Management Center of the receiving host has a home alarm host of features, can also be achieved through the RS232 communication center and property management functions, networked and community control.
1.1.1 DTMF transceiver circuit
Remote Communication to Achieve telephone line, a Key Part of the DTMF Transceiver Circuit. It Will automatically Dial, Busy Tone recognition, Tone recognition, Remote Key access features such as Digital Signal recognition. We use multi-MT8888 Dual Tone Frequency (DTMF) Transceiver and MCU and audio amplifier portfolio, to achieve a variety of detection and DTMF tone signal generation, and DTMF signal to the telephone line, shown in Figure 3.
MT8888 is the use of CMOS Technology, the DTMF Transceiver Signal Integrated Circuits. It is used to Send some Signal Distortion, High Stability of the Switching Frequency capacitive D / A converter, may be issued 16 kinds of multi-Frequency DTMF Dual Tone signals. DTMF signal receiving part of the makeup used to complete the collection, separation and decoding, and 4-bit parallel binary code to the way output

elect the interrupt mode, when receiving or sending a valid audio signal IRQ / CP output pin low, generate an interrupt signal supplied CPU, the delay control voltage jump to the edge of the data latch output; When you select a call (CP) mode , can only receive 250 ~ 550Hz tone signal, the rejection or no input, IRQ / CP pin output low.
(1) phone tones format
Busy Tone: 450Hz, there 350ms, 350ms None. Dial Tone: 450Hz, continue. Ringback Tone: 450Hz, 1s there, 4S Free.
(2) The way to judge the tone of the
The MT8888 the IRQ / CP pin is connected to the T0 AT89S52 feet, ALL Phone calls during the Tone by limiting MT8888 Filter Square Wave Obtained from the IRQ output to MT8888 AT89S52 the T0 pin count on the T0 pin Signal 5S. 2175 ~ 2357 Counts in the Range for the Dial Tone; count value in the Range of 1041 ~ 1212, as a Busy Tone; count value in the Range of 425 ~ 475 for the Ring Back Tone. In the actual Programming, taking into account the count and Error simplified procedures, the range may be appropriate to relax, but not overlap.
(3) Automatic hook
Controller and the Home Phone and connected to a telephone line. In order to Achieve the Alarm Call put a line Sharing, Pick Electromechanical Road SET as follows: the telephone Ringing Signal through the AT89S52 the IT INPUT OPTOCOUPLER TP521 to the feet, were counted. received a Ringing Signal, a Continuous Ring 10 times if the User does not Pick up, you automatically Go Home Intelligent Alarm, CPU SET pin P1.5 to "1", pull the relay K1, Automatic picking function. If the Ring 10 times in this Process, the User connected to the Phone, the Controller does not respond, SO that makes the Controller and the Phone does not interfere with each other. Hook, the multi-test MT8888 Dual Tone Frequency output signals sent to the Information to Read user's remote, remote communications and control functions.

(4) Automatic alarm
Upon receipt of the pyroelectric Sensor, a Wireless Alarm Signal sent by Post, CPU Send Alarm signals transmitted immediately through the telephone line Remote users. Alarm as follows: the User Equipment 10 Via Alarm Panel, Phone and put them into the 24C04 Memory. When , after receiving the Alarm, starting from a telephone Dial-up, has been appropriated for the First 10 Back to 3 times. If any one Phone to Send Back a "#" Key to Confirm the Signal, which means that the Alarm has been received and no longer Continuing to Dial. Need to Dial each number. No need to Dial each Time 100ms, 500ms interval left between Numbers. Dial-up, the First Detection of Phone Numbers stored in 24C04. If IT is empty, that is, Phone this is not SET, skipped Away, continue to Dial the telephone number Next. In this Way, users can freely SET the number of Phone Numbers. We require that number up to more than Four lengths in order to exist in the 24C04.
1.1.2 voice circuits
In order to facilitate Communication, using a Voice Chip, Voice instructions and Alarm function. ISD1420 single-Chip Voice Recording, Playback, Integrated Chips, Record length is 20S; can be divided into 160 pieces, each 125ms. When the REC pin is Low , recording, PLAYE or PLAYL when playback is low, ISD1420 continuous recording can also be segmented recording.

Playback section: the first code sent to stop the recording and reproducing P1.2 ~ P1.4 = 000, sending the first address of the playback A7 ~ A0, P1.3 or P1.4 is low (PLAYE or PLAYL) start playback ; the Playback delay, and finally sent to STOP the Recording and Reproducing code P1.2 ~ P1.4 = 000, the completion of this section of the Playback. Repeat the above Sub-Process can be released sections of the Speech. Figure 4 shows speech circuit.
1.1.3 encoder / decoder circuit
PT2262/2272 Cape Town in Taiwan produced a Low-Power CMOS Process Technology, Low-cost, General purpose codec Circuit. PT2262/2272 up to 12-bit (A0 ~ A11) Tri-State address Terminal Pins (Vacant, then High, then low), any combination can provide 531,441 address codes.

PT2262 can have up to six (D0 ~ D5) Data End pin, code and SET the address output pin Serial Data from 17 Yards. Encoding Chips PT2262 Coded Signal sent from the address code, Data code, code to form a Synchronization Word Complete code . Address code within the Host Family must Control the Decoder Chip PT2272 Addressing the same, to distinguish between Family Control; Data code can be used to distinguish the Sensor type. When an Alarm Signal, PT2262 14-pin Low, Enabling PT2262, 17 feet from the output code signal transmitted out through RF module.
PT2272 receives the Signal Decoder Chip, Comparing the address code checked twice, VT output pin was High, to the 89S52 of INT1, an interrupt handler to Read Data D0 ~ D3 code, that Alarm Sensor Status and Alarm type. Figure 5 shows the Encoder / decoder circuit.
1.1.4 RF module and the RF receiver module
RF Transmitter Receiver RF module and the module principle is shown in Figure 6 and Figure 7, the Working Frequency of 433MHz. Maximum Transmission Distance up to 1000m.
1.2 Sensor Design
1.2.1 Pyroelectric passive infrared sensor
A Constant body temperature, generally at 37 ?, IT Will issue a specific infrared wavelength of about 10µm. Passive infrared Sensor is the Human body by detecting the infrared emission around 10µm carried out the work. Body infrared emission around 10µm, Enhanced by the Fresnel Filter, Sensors gather infrared source. Source of commonly used pyroelectric infrared sensing Devices. This Device receives the infrared radiation the Human body Will be Lost when the temperature changes the charge Balance out the Release of charge, follow-up testing after the Circuit generated by the alarm signal.
Figure 8 for the Dual element pyroelectric infrared Detection LHI968's internal Circuitry. It consists of two Dual element pyroelectric ceramic, Induction infrared signals, then amplified by the FET output. D-Side of the resistance and capacitance of S-Side with anti-electromagnetic interference .

Signal from the S Side leads by Preamplifier, amplified through the 47µF capacitor and Again the threshold Comparison SET, access to the Alarm Signal output. 47µF capacitor in addition to the DC Component,Eliminating the use of the Environment (Sun, Light, Fire source, etc.) Impact on the Detector, followed by the Trigger Circuit for a delay to the owner Maximum Security and Disarm. Now have specific Integrated Chip BISS0001 Achieve the above functions. Disarm in order to Meet the needs of the owner came in the Door, the Alarm Circuit designed delay. Delay length shall be satisfied: when the Person to 1M / s Speed of Movement from the Front of the Detector 0.2m, not an Alarm; but mobile 3m should be alarm, test speed should be able to detect 0.3 ~ 3m / s or the wider speed range.
1.2.2 Magnetic surprise transfer device
Wireless Door Magnetic Sensors are generally above the Files Inside of the Door. It consists of two Parts: Part for a Smaller the Permanent MagNet, the Inside has a Permanent MagNet used to generate a Constant Magnetic Field; Wireless Door Sensor larger body, the Inside normally has a type of Open Reed. When the Permanent MagNet and the Reed Switch when in Close Proximity (less than 5mm), Wireless Door Magnetic Sensor in the work of Waiting for the State; When Reed left the MagNet after a certain Distance, Wireless Magnetic Door Sensors, and immediately launched its own Identification code contains the address code (that is, Data code) of 433MHz High-Frequency Radio signals. Host of Radio signals by identifying the address code to determine whether an Alarm System for the same, then according to its own identification number (that is, data code), to determine which a wireless door sensor alarm.
2 Network Design center control console
Network Design Center Control Console Controller Family is Basically the same, but added a RS232 interface and PC-connected to Achieve. Property Management Center through the PC, on the realization of community Network Monitoring.
Conclusion
Using the existing telephone network, combined with radio frequency wireless communication technology and SCM network control technology, the economy of the anti-theft alarm system, reliable, flexible networking; home wiring without the need for the sensor; has a broad market prospect.