基于DTMF的智能电话控制器.doc

DTMF-based intelligence telephone controller(Source: Monolithic machine and dyadic implantation system application)Abstract: Introduce one kind of DTMF (dual-tone multifrequency) signal and RS485-based long-range intelligence controller. It has ringing detecting and the signal simulating Off Hook , DTMF decoding , infrared remote control code certainly lifts the function studying and launching the multi-path infrared remote control signals. Composition , hardware allocation, software to that controller design , operating principle , the function discuss detailedly as well as the technology function has been in progress the main body of a book. That controller uses the queen , testifies the person convenient , reliable and has practical value in long-range under the control of data terminal system.Keywords: DTMF； RS485；Infrared remote control；MT88701 SummaryHorizontal going a step further improves with the industrial automation, industry scene guarding in a lot of self-service, hope is able to carry out long-range controlling on equipment and monitor , interposes with data collect as well as are in progress to long-range data terminal. Telephones gradually universal the scene installs a telephone will do in industry becoming possibility. The in-bridge having designed and making one kind of DTMF (Dual Tone Multiple Frequency)-based multiplex telephony controller according to this condition , us, as long as with telephone controller can pass it right away on industry scene telephone line, with using telephone now and then everywhere to equipment be in progress on-off control, data acquisition, long-range interpose and so on . Besides, horizontal ceaseless society economy rise already begins urge the family automation, people is hoped being able to put long-range supervisory control into practice always and everywhere to family safety and puts long-range under the control of into practice to the home appliance. Because the telephone line is that the whole nation is networked , remote control distance can stride over the province city. Be a controllers turn to adopt the monolithic machine and pronunciation chip , may make use of pronunciation to handle the hint being in progress to diversity may couple back the information square state is charged together.红外接收电路44键盘液晶显示器24C02串行存储器振铃检测、模拟摘机电路双音多频解码译码电路89C51单片机89C51单片机红外发射电路八路开关量输出八路开关量输入时钟定时电路语音控制电路RS232串行通信、RS485串行通信电路电话线 Picture1 Principle block diagram2. Composition and principle controlling2.1 The controller operating principleThe electromechanical includes a round number if the road pursuing what picture1 shows: Ringing checks and the simulation extracts the electromechanical route, MT8870 wait for the decoding circuit being composed of, infrared generate the launch circuit , octuplex switch amounts import and octuplex switches amounts export a control circuit , pronunciation under the control of and record readjust oneself to a certain extent circuit, clock circuit being composed of DS12887, RS232 or RS485 strings the infrared signal self study circuit that row of the circuit communicating by letter , apposition keyboard and liquid crystal display compose together.Be the controller operating principles turn: While needing long-range under the control of, allocate since the corresponding telephone number , the ringing detecting circuit check the bell stream signal. (Number of times can pass a software after ringing number of times reaches 5 time arbitrarily set up), 89 C51 control the monolithic machine realizing circuit automation Off Hook, and the starting pronunciation circuit issues a hint importing a password. The password carries out a check by that the receiving circuit receiving and importing middle to monolithic machine , check rightness prompts then importing the control command key, the monolithic machine carries out analyse a judgement, and corresponding according to ordering a request to be completed operation on order. Serve as the entering * key queen, the automation realizes telephone on-hook , accomplish a long-range under the control of thereby. If 30 s inner of Off Hook not importing order or the password, circuit meeting automation on-hook; By the same token, if importing a button exceed also automatic on-hook of eight keys.The controller the equipment being able to string the function doing the long-range circuit realization information collect communicating by letter , controlling some switch amounts and having infrared remote control together by RS485; Functions such as may start up by the fact that the long-range telephone or computer interposes regular time or shutting machine down.2.2 The circuit is composed of hardware2.2.1 Ringing checks , plucks the electromechanical roadThe ringing checks circuit is that couple T521-1 and 74 LS123 compose from brightness. Should there be telephone breathed out fashionable, 25 Hz , 90 V bell signals export pulse signal from commutation queen photoelectricity isolation. In being pulses turn to import to 74 LS123, 74 LS123 make minor pulse counting in forming the expert wave signal , sending in the monolithic machine. Ding-dang counting is reached when setting up number of times, the monolithic machine Picture2 Ringing checks , plucks the electromechanical roadcontrols the high level outputing , messenger audion leads , thereby, the relay attracts the small side door , accomplishes a simulation extracting expedient work. Since pronunciation signal and pair of an audible signals voltage are way below bell signal voltage, be a circuits turn to be able to not arouse an erroneous judgement therefore. Ringing checks , plucks an electromechanical if the road pursuing what picyure 2 shows.2.2.2 Dual-tone multifrequency demodulator circuitMT8870 is that the DTMF signal receives the special use chip handling , whose function is to will receive the decoding to DTMA signal for two 4 makes a code, from Q1 Q4 direct output. After simulating Off Hook, the dual-tone multifrequency signal imports a foot by that the coupling isolation transformer coupling enters MT8870. After an audible signal filters that pair except dial tone signal first after internal dial tone of MT8870 wave filter, send in pair of VF wave filter again as a result of prepose an amplifier, pair of an audible signals is split according to height , the low frequency signal, the detector sends in the decoding circuit after height , low frequency wave filter , extent, the final data output from MT8870 holds corresponding code of output. Receive the AT89C51 INT0 for STD gaining the effective data , MT8870. Think that STD electrical level receives the effective dialing key value code from being changed into height low , being passing the P1 mouth highway by that AT89C51 checks the queen. Dual-tone multifrequency decodes a circuit if pursuing what picture 3 shows. Picture3 Dual-tone multifrequency demodulator circuit2.2.3 Pronunciation controled and pronunciation record circuitPronunciation under the control of and pronunciation record put in a circuit if pursuing what 4 shows , adopt the ISD2590 chip to do the figure sound recording component. Record puts in time may amount to 90 ses , can be continuous record readjust oneself to a certain extent also being able to readjust oneself to a certain extent by the fact that address wire A0 A9 chooses piecewise record. Pronunciation chip ISD2590 movie selections input end CE is to start the playback period time low pulse. The playback not following CE electrical level returning to highly but is over. CE signal coming down follows to start the sound recording period. The PD foot is to enter low-power consumption state time height. The selected playback handles the P/R input end for high electricity in the ordinary time , the selected low electricity sound recording the ordinary time handles. Corresponding pronunciation Duan playing comes to come true from the software. The signal that ISD2590 SP + , SP-hold gives the amplification being in progress till VF enlarges circuit LM386 , go through the isolation transformer coupling again till telephone circuit, the consumer can hear the hint that system under the control of pronunciation chip issues li from telephone, to carry out corresponding operation. ISD2590 Picture 4 Pronunciation control and pronunciation record2.2.4 Infrared launch circuit555 formation produces 38.5 kHz pulse oscillating circuits from time base circuit , the launch realizing the passage choice outputing with GAL16V8 logic array component and overlaying the carrier signal exporting 38.5 kHz acting as 2803 drive queens who control output , pass through octuplex drive goes out. Monolithic machine that P1.4 , P1.5 , P1.6 are GAL16V8 three passage choice entering of 89 C51, that P1.7 accomplishes makes to be able to control. Think that P1.7 is that the high electricity forbids outputing in the ordinary time,; Think that P1.7 is that the low electricity allows output in the ordinary time. From 89, C51 monolithic machine timer T0 controls the infrared pulse string width and gap. Be to improve the anti-interference ability and carry out reliable communication, some remote control implement needs to the all kinds of guidance code be thrust into, for the purpose of the receiver is easy to distinguish before dispatching binary system code. For the remote control implement distinguishing the different type,need to dispatch an address code and to check a code. Code strong point dispatched by other , different remote control implement is neither identical. The infrared launch is as circuital as picture what 5 shows. Picture 5 Infrared launch circuit2.2.5 Other circuitThe controller has increased real time clock circuit DS12887 , may be provided standard space by system. The controller has the timing under the control of function at the same time. The controller may communicate by letter by the fact that the RS485 long-range communicate by letter interface and the superordination computer are in progress , may interpose time the regular time , the infrared signal code being unlike a type etc., the computer of Deng available issues the information ordering realizing long-range under the control of and fetching acquisition to the controller.3.The software designed3.1 89C51A procedure(1) Ringing checks and simulates Off Hook procedureCompare according to the ringing number of calls , the detecting being in progress that the software sets up. While getting to setting value, start Off Hook and the pronunciation hint.(2) DTMF receives and sends INTERP an orderThe monolithic machine receives the data from MT8870 output, and judges if this paragraph of procedure is the queen who simulates Off Hook mainly , be over. Import the queen who is over , analyse the what data and carry out corresponding operation.(3) Serial communication procedureReceive superordination machine order and carry out corresponding operation mainly.(4) Pronunciation record puts in and controls procedure3.2 89C51B procedure(1) Infrared received procedureUse INT0 to stretch a foot as importing , produce interruption , start timer T0 beginning to reckon by time while having coming down following. After thinking that INT0 stops the plan numerical value reckoning by time , reading and deposits to memory when from low to high, start regular time again.(2) The infrared code of self study handles analysis procedureAccording to the time value storing infrared signal high level and low level in memory,judge having guiding a code or not. If having, find out the high level attracting the foot code and the low level period value. By comparison , the computer information code basic, again, 0 and 1 period t , t0 , t1, find out the address code , the information code and deposit to memory.(3) Pair of monolithic machine parallel communication procedureBreak off , fetch a data between 2 monolithic machine by the fact that INT1 comes into being. The parallel communication form is: Guide the code , byte number N , send the code , the data an order 1, data 2, . Data N-2 , checking code.(4) Keyboard scan and liquid crystal display procedure(5) Infrared launch procedureInfrared output signal realization procedure: According to what be needed to control order, queen who chooses corresponding passage, the remote control control code is taken out from EEPROM middle send in shifted buffer area , the code judging needing to lead or not. The later shifted remote control control code, makes P1.4 be that height , the period are t first , makes P1.4 be that the period is t1 low and then again while shifting is 1. Departure many 1 and 0 are the length according to remote control control code but fix; When sends out 1 and 0 , comes to decide from the address code and the control code.4.Concluding remarkThis system has very strong adaptability , equipment , domestic appliances of all kinds being able to be long-range to industry scene are in progress under the control of, change , assemble and defend the practical value that cost has conveniently, low, as a result comparatively highly in having no need of the arrangement of wire to already some industry scene or dwelling house time installation acting as any. Furthermore , originally systematic convenient operation simplicity, the consumer can import the instruction retrenching and revise a password right away by telephone set (disregarding being hand-free telephone be still cellular phone),; Can point out the operation being in progress according to pronunciation, therefore that system has higher application and dissemination value.基于DTMF的智能电话控制器摘要：介绍一种基于DTMF（双音多频）信号和RS485的远程智能控制器。它具有振铃检测和模拟摘机、DTMF信号解调、红外遥控编码自举学习和发射多路红外遥控信号的功能。本文对该控制器的组成、硬件配置、软件设计、工作原理、功能以及技术性能进行了详细论述。该控制器在远程控制的数据终端系统中使用后，证明其方便、可靠和有实用价值。关键词：DTMF RS485 红外遥控 MT88701 概述随着工业自动化水平的进一步提高，在许多无人看守的工业现场，希望能够对设备进行远程的控制和监测，以及对远程数据终端进行设置和数据采集。电话的逐渐普及使得在工业现场安装电话成为可能。根据这种情况，我们设计并制作了一种基于DTMF（Dual Tone Multiple Frequency）的多路电话控制器，只要将电话控制器并接在工业现场的电话线上，就可以通过它随着时随地用电话对设备进行开关控制、数据采集、远程设置等1。另外，社会经济水平的不断提高已经开始促使家庭自动化，人们希望能够随时随地对家庭安全实行远程监控以及对家电实行远程控制。由于电话线路是全国联网的，所以遥控距离可以跨省市。该控制器采用单片机和语音芯片，可利用语音对于不同操作进行提示并可反馈受控方状态的信息。2 控制的组成及原理2.1 控制器的工作原理整机电路如图1所示，包括：振铃检测与模拟摘机电路，由MT8870等组成的解码电路，红外生成发射电路、八路开关量输入和八路开关量输出控制电路，语音控制和录放电路，由DS12887组成的时钟电路，RS232或RS485串行通信电路，外加键盘和液晶显示构成的红外信号自学习电路。红外接收电路44键盘液晶显示器24C02串行存储器振铃检测、模拟摘机电路双音多频解码译码电路89C51单片机89C51单片机红外发射电路八路开关量输出八路开关量输入时钟定时电路语音控制电路RS232串行通信、RS485串行通信电路电话线 图1 原理框图该控制器的工作原理：当需要远程控制时，拨打相应的电话号码，振铃检测电路检测铃流信号。振铃次数达到5次后（次数可以通过软件任意设定），单片机 89C51控制实现电路自动摘机，并启动语音电路发出提示输入密码。密码经接收电路接收并输入到单片机中进行核对，核对正确则提示输入控制命令键，单机对命令进行分析判断，并根据命令要求完成相应的操作。当输入“*”键后，自动实现电话挂机，从而完成一次远程控制。摘机的30s内若不输入命令或密码，电路会自动挂机；同样，若输入按键超过8个键也自动挂机。该控制器还可以通过RS485串行通信电路实现远程信息采集，控制若干开关量和具有红外遥控功能的设备；还可通过远程电话或计算机设置定时开机或关机等功能。2.2 硬件电路组成 2.2.1 振铃检测、摘机电路振铃检测电路是由光耦T521-1和74LS123构成的。当有电话呼入时，25Hz、90V振铃信号由整流后光电隔离输出脉冲信号。该脉冲输入到 74LS123中，74LS123将小脉冲整形成大方波信号，送入单片机中计数。当计数达到设定次数时，单片机控制输出高电平，使三极管导通，从而继电器吸合，完成模拟摘机动作。由于语音信号和双音频信号电压远低于振铃信号电压，因此该电路不会引起误判。振铃检测、摘机电路如图2所示。2.2.2 双音多频解调电路MT8870 是DTMF信号接收处理的专用芯片，其功能是将接收到的DTMA信号解码为4位二制码，由Q1Q4直接输出。模拟摘机以后，双音多频信号经过耦合隔离变压器耦合入MT8870输入脚。该双音频信号先经MT8870内部的拨号音滤波器滤除拨号音信号后，再经前置放大器送入双音频滤波器，将双音频信号按高、低频信号分开，又经高、低频滤波器、幅度检测器送入译码电路，最后从MT8870的数据输出端输出相应的编码。为了获取有效的数据，MT8870的STD 接