CN111538300A

CN111538300A - Intelligent home remote control system based on telephone network and control method thereof

Info

Publication number: CN111538300A
Application number: CN202010339934.3A
Authority: CN
Inventors: 卢健; 杨腾飞; 周嫣然; 罗毛欣; 李哲
Original assignee: Xian Polytechnic University
Current assignee: Xian Polytechnic University
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2020-08-14

Abstract

The invention discloses an intelligent home remote control system based on a telephone network, which comprises a ringing detection module and a DTMF dual-tone frequency coding and decoding module which are respectively connected in parallel at two ends of a home telephone, wherein the output end of the ringing detection module is connected with a main controller; the signal sending part and the receiving part of the DTMF dual-tone encoding and decoding module are both connected with the main controller; the main controller is connected with the input end of the analog on-off module, and the analog on-off module is connected with the telephone in series to realize the on-off control of the circuit; the main controller is also connected with a voice prompt module, the voice prompt module is connected with a power amplification circuit, the power amplification circuit is connected to a telephone line in parallel, and the voice prompt module prompts a user to operate the controller; the clock module in the main controller is connected with the display module; and a control pin on the main controller is connected with the electric appliance and used for controlling the on-off and state of the electric appliance.

Description

Intelligent home remote control system based on telephone network and control method thereof

Technical Field

The invention belongs to the technical field of intelligent home furnishing, and relates to an intelligent home furnishing remote control system based on a telephone network, and a control method of the control system.

Background

An intelligent home Control system (SCS) is characterized in that a home is taken as a platform, home appliances and household appliances are taken as main Control objects, and facilities related to home life are efficiently integrated by utilizing a comprehensive wiring technology, a network communication technology, a safety precaution technology, an automatic Control technology and an audio and video technology to construct an efficient Control management system for home facilities and home schedule transactions. In 1984, the concept of smart home systems was proposed, and since then, the development trend of global smart homes has pulled a curtain, and in short decades, the development of smart homes has achieved a rapid research result. In China, the intelligent home is put forward more late than the foreign development for a few years, but through the development innovation and market cultivation of the few years, the domestic subject also reaches a peak, and the intelligent home control becomes a new home form which is widely known.

With the development of society and the gradual improvement of living standard of people, more and more household appliances enter the lives of people, the household appliances bring much convenience and enjoyment to the lives of people, and meanwhile, with the great popularization of telephones in families, the remote control of the household appliances by utilizing a telephone network is the future development direction of the household appliances. Therefore, the design of a telephone network control system capable of remotely controlling the traditional household appliances has substantial times significance.

The telephone remote control system is a branch of the intelligent home control system, and by combining the rapidly developed telecommunication technology with various subsystems related to home life closely, the home life is more comfortable and safer through overall management. Compared with the common home, the remote control type intelligent home not only provides convenience for people, creates a simple and comfortable home living environment, but also converts the original purely static home appliances into more humanized tools, helps the home owner to better manage, operates the household equipment, can keep communication with the home even when going out, optimizes the life style of people, effectively arranges the working time for the people, and guarantees safety, high efficiency, reasonable utilization of resources and the like.

Disclosure of Invention

The invention aims to provide an intelligent home remote control system based on a telephone network, which solves the problem that radio remote control inevitably occupies certain radio frequency resources to cause electromagnetic pollution in the prior art.

The invention also aims to provide a control method of the intelligent home remote control system based on the telephone network, which solves the problem that the radio remote control in the prior art inevitably occupies certain radio frequency resources to cause electromagnetic pollution.

The technical scheme adopted by the invention is that the intelligent home remote control system based on the telephone network comprises a ringing detection module and a DTMF dual-tone frequency coding and decoding module which are respectively connected in parallel at two ends of a home telephone, wherein the output end of the ringing detection module is connected with a main controller; the signal sending part and the receiving part of the DTMF dual-tone encoding and decoding module are both connected with the main controller and are used for realizing the sending and receiving of the DTMF dual-tone multi-frequency signals; the main controller is connected with the input end of the analog on-off module, and the analog on-off module is connected with the telephone in series to realize the on-off control of the circuit; the main controller is also connected with a voice prompt module, the voice prompt module is connected with a power amplification circuit, the power amplification circuit is connected to a telephone line in parallel, and the voice prompt module prompts a user to operate the controller; the clock module in the main controller is connected with the display module, and the display module is used for realizing state display, time display and online modification of the electric appliance; and a control pin on the main controller is connected with the electric appliance and used for controlling the on-off and state of the electric appliance.

The invention is also characterized in that:

the main controller adopts an STC89C52 singlechip.

The circuit structure of the ringing detection module is as follows: a capacitor C1, a resistor R1 and a resistor R3 are sequentially connected in series on the telephone line 1, a resistor R2 and a voltage stabilizing diode D1 are sequentially connected in parallel between the telephone line 1 and the telephone line 2 between the resistors R1 and R3, the other ends of the resistor R3 and the voltage stabilizing diode D1 are respectively connected to the input end of a photoelectric coupler U1, a telephone ringing signal is isolated through the capacitor C1, the voltage stabilizing diode D1 stabilizes voltage, and the signal is input to the input port of the photoelectric coupler U1 through the R3 after the voltage division processing of the resistor R1 and the resistor R2; the output end of the photoelectric coupler U1 is connected with an amplifying circuit consisting of resistors R4, R5 and a phototriode Q1, and the other end of the amplifying circuit is connected with an input pin of an interrupt counter in the main controller; a ringing indicator lamp is also connected in parallel between the photoelectric coupler U1 and the main controller, and the ringing indicator lamp is formed by connecting a resistor R6 and a light-emitting diode D2 in series.

The DTMF dual-tone encoding and decoding module adopts an MT8880 dual-tone multi-frequency decoding chip to realize the sending and receiving of dual-tone multi-frequency signals DTMF.

The circuit structure of the analog on-hook and off-hook module is as follows: the telephone line 1 is connected with the upper port of a rectifier bridge BR1, and the right port of the rectifier bridge BR1 is connected with a matching resistor R10; the telephone line 2 is connected with the lower port of the rectifier bridge BR1, a relay is connected between the telephone line 2 and the rectifier bridge BR1, the lower end of the relay is connected with a diode D2 in parallel, the other end of the diode D2 is connected with the emitter of a triode Q2, the collector of the triode Q2 is connected with a resistor R10 and then is grounded, the base of the triode Q2 is connected with resistors R7 and R9 in parallel to form a switch circuit, the switch circuit is also connected with an analog off-hook indicator light consisting of a resistor R8 and a light emitting diode D3 in parallel, and the other end of the light emitting diode D3 is connected with an analog off-hook control pin on the main controller.

The voice prompt module adopts a voice chip ISD 4004.

The display module adopts an LCD1602 liquid crystal display.

According to the control method of the intelligent home remote control system based on the telephone network, when a user needs to control home appliances in a home, the user can dial a telephone number in the home, the switchboard can send a ringing signal to a telephone in the home, when the ringing signal comes in, a ringing detection circuit of a ringing detection module of the system can receive the ringing signal and convert the ringing signal into a pulse signal which is sent into the main controller through a timing counting interrupt port of the main controller for counting operation, when the counted ringing times reach the set times, no one answers, an interrupt application can be submitted to the main controller, and after the main controller responds to an interrupt request, a control port of the analog pick-up module is at a low level, the analog pick-up circuit is started, and automatic pick-up is realized; after the circuit is connected, the main controller enables the voice chip connecting end of the voice prompt module to be at a low level, sends a control command to start the voice prompt circuit, voice prompt information is transmitted to a telephone line to prompt a user to input a password, the password input by the user is converted into a corresponding binary number through a decoding circuit of the DTMF dual-tone encoding and decoding module, the binary number is sent to the main controller to carry out password verification, if the password is correct, the main controller controls the voice prompt module to send a voice prompt for next operation, if the password is wrong, the prompt is input again, and if the password is wrong, the prompt is wrong for three times, the main controller controls a control port of the analog pick-up and hang-up module to be at a high level, circuit communication is cut; the display module is used for realizing the state display, the time display and the online modification of the electric appliance and can record the operation time in real time; after the password is correct, the state query of the control equipment and the equipment can be selected under the voice prompt of the voice prompt module, if the control operation of one electric appliance is finished and another electric appliance needs to be controlled, the operation needs to be returned by pressing the 'x' key, and if the operation does not need to be carried out or is finished, the operation is finished by pressing the '#' key, and the remote control operation is finished.

The invention has the beneficial effects that: the problem that the radio remote control inevitably occupies certain radio frequency resources in the prior art to cause electromagnetic pollution is solved; the conventional wired remote control needs special wiring, so that the investment is increased; and the infrared ray and ultrasonic remote control have the problems of distance limitation and the like. Therefore, telephone remote control as a new subject shows certain superiority compared with other modes, because the telephone lines are connected with the internet in various places and can be fully utilized, the remote control distance can span provinces and cities, even countries, and the telephone belongs to a duplex communication mode, so that the telephone has good application background for remote control.

Drawings

FIG. 1 is a schematic structural diagram of a telephone network-based smart home remote control system according to the present invention;

FIG. 2 is a control flow chart of the intelligent home remote control system based on the telephone network according to the present invention;

FIG. 3 is a pin diagram of a main controller STC89C52 single chip microcomputer in the intelligent home remote control system based on the telephone network;

FIG. 4 is a diagram of MT8880 functional pins in the intelligent home remote control system based on the telephone network according to the present invention;

FIG. 5 is a control bitmap of an SPI port in the intelligent home remote control system based on the telephone network according to the present invention;

FIG. 6 is a schematic circuit diagram of a ringing detection module in the remote control system of the smart home based on the telephone network according to the present invention;

FIG. 7 is a schematic circuit diagram of a simulated pick-up and hang-up in the intelligent home remote control system based on the telephone network according to the present invention;

FIG. 8 is a schematic circuit diagram of a DTMF dual tone codec module of the intelligent home remote control system based on the telephone network of the present invention;

FIG. 9 is a schematic circuit diagram of a voice prompt module in the remote control system for smart home based on telephone network according to the present invention;

FIG. 10 is a connection diagram of control pins in the remote control system for smart home based on telephone network according to the present invention;

FIG. 11 is a schematic diagram of an LCD1602 LCD circuit in the remote control system of smart home based on telephone network according to the present invention;

FIG. 12 is a flow chart of a ringing count module in the remote control system of the smart home based on the telephone network according to the present invention;

fig. 13 is a flow chart of password detection in the intelligent home remote control system based on the telephone network according to the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention relates to an intelligent home remote control system based on a telephone network, which comprises a ringing detection module and a DTMF dual-tone frequency coding and decoding module which are respectively connected in parallel at two ends of a home telephone, wherein the output end of the ringing detection module is connected with a main controller; the signal sending part and the receiving part of the DTMF dual-tone encoding and decoding module are both connected with the main controller and are used for realizing the sending and receiving of the DTMF dual-tone multi-frequency signals; the main controller is connected with the input end of the analog on-off module, and the analog on-off module is connected with the telephone in series to realize the on-off control of the circuit; the main controller is also connected with a voice prompt module, the voice prompt module is connected with a power amplification circuit, the power amplification circuit is connected to a telephone line in parallel, and the voice prompt module prompts a user to operate the controller; the clock module in the main controller is connected with the display module, and the display module is used for realizing state display, time display and online modification of the electric appliance; and a control pin on the main controller is connected with the electric appliance and used for controlling the on-off and state of the electric appliance.

The main controller adopts an STC89C52 singlechip.

The voice prompt module adopts a voice chip ISD 4004.

The display module adopts an LCD1602 liquid crystal display.

According to the control method of the intelligent home remote control system based on the telephone network, when a user needs to control household appliances in a home, the user can dial a telephone number in the home, the switchboard can send a ringing signal to a telephone in the home, when the ringing signal comes in, a ringing detection circuit of a ringing detection module of the system can receive the ringing signal and convert the ringing signal into a pulse signal which is sent to the main controller through a timing counting interrupt port of the main controller for counting operation, when the counted ringing times reach the set times, no one answers, an interrupt application can be provided for the main controller, and after the main controller responds to the interrupt request, a control port of the analog pick-up module is at a low level, the analog pick-up circuit is started, and automatic pick-up is realized; after the circuit is connected, the main controller enables the voice chip connecting end of the voice prompt module to be at a low level, sends a control command to start the voice prompt circuit, voice prompt information is transmitted to a telephone line to prompt a user to input a password, the password input by the user is converted into a corresponding binary number through a decoding circuit of the DTMF dual-tone encoding and decoding module, the binary number is sent to the main controller to carry out password verification, if the password is correct, the main controller controls the voice prompt module to send a voice prompt for next operation, if the password is wrong, the prompt is input again, and if the password is wrong, the prompt is wrong for three times, the main controller controls a control port of the analog pick-up and hang-up module to be at a high level, circuit communication is cut; the display module is used for realizing the state display, the time display and the online modification of the electric appliance and can record the operation time in real time; after the password is correct, the state query of the control equipment and the equipment can be selected under the voice prompt of the voice prompt module, if the control operation of one electric appliance is finished and another electric appliance needs to be controlled, the operation needs to be returned by pressing the 'x' key, and if the operation does not need to be carried out or is finished, the operation is finished by pressing the '#' key, and the remote control operation is finished.

As shown in figure 1, the system is connected in parallel at two ends of a household telephone, and when an incoming call comes, the normal work of the telephone is not influenced. The control system is composed of a ringing detection module, an analog on-hook and off-hook module, a DTMF dual-tone frequency coding and decoding module, a voice prompt module, a clock display module and a control pin. The system uses STC89C52 single chip as core control device, MT8880 as main control chip of DTMF signal receiving circuit, voice chip ISD4004 as voice recording and playing core device, device LCD1602 as display tool, and phone as medium to complete remote control operation of equipment via phone line.

STC89C52 is a low power consumption, high performance CMOS8 bit microcontroller manufactured by STC corporation having an 8K on-system programmable Flash memory. On a single chip, a smart 8-bit CPU and a system programmable Flash are provided, so that STC89C52 provides a high-flexibility and ultra-effective solution for a plurality of embedded control application systems. The following standard functions were provided: 8 kbyte Flash, 512 bytes RAM, 32 bit I/O port line, watchdog timer, built-in 4KB EEPROM, MAX810 reset circuit, 3 16 bit timers/counters, 4 external interrupts, a 7 vector 4-level interrupt structure (compatible with the traditional 51 5 vector 2-level interrupt structure), and full-duplex serial port. The maximum operation frequency is 35MHz, and 6T/12T is optional. The pins of STC89C52 are shown in fig. 3. (1) RST: reset input; (2) PSEN: a strobe signal of the external program memory; (3) EA/VPP: accessing the internal program memory when the EA is held high, and accessing only the external program memory when the EA is held low, regardless of whether there is an internal program memory; (4) XTAL1, XTAL2, input end and output end of the oscillator inverting amplifier and the internal clock generating circuit; (5) ports P0 to P3: port P0 is a bidirectional I/O port. Port P0 is also multiplexed as a lower 8-bit address/data when accessing external program and data memory. An external pull-up resistor is required for program verification. The ports P1, P2 and P3 are 8-bit bidirectional I/O ports with internal pull-up resistors, and the port P2 sends an upper eight-bit address when accessing an external program memory or reading an external data memory with a 16-bit address.

MT8880 is a single-chip DTMF signal transceiver with call processing filters. The low power consumption and high stability ISO-CMOS technology of MITEL is adopted. The receiving part of the DTMF signal adopts the industrial manufacturing standard of a DTMF signal receiving singlechip MT 8870; the transmitting part adopts a switched capacitor to carry out D/A conversion and transmits DTMF signals with high precision and low distortion. The internal register provides a group pattern. In dual tone cluster mode, DTMF signals can be transmitted with precise timing. The call processing filter may be selected to allow a microprocessor to process the call audio signal. The pin function: (1) IN +, IN _: the input end is the non-inverting input end and the inverting input end of the internal amplifier, namely the input end for receiving DTMF signals; (2) GS: the output end of the Gain Select internal amplifier is externally connected with a negative feedback resistor to the IN _ end; (3) VREF: an internal reference voltage output, the reference voltage equal to UDD/2; (4) VDD, VSS: the power supply is respectively the positive end and the negative end of the power supply, and the power supply voltage is 5V; (5) OSCl, OSC 2: the DTMF clock/oscillator input is externally connected with a clock crystal of 3.579545MHz to form a crystal oscillator; (6) TONE: a dual audio signal output; (7) R/W: a read/write control terminal for reading the MT8880 when applied with a high level and writing the MT8880 when applied with a low level; (8) CS: the chip selects the end, the low level is effective; (9) RS 0: and a control terminal for selecting each internal register, the control terminal selecting the control register or the status register when a high level is applied, and selecting the transmission data register or the reception data register when a low level is applied. (10) Phi 2: a synchronization pulse (clock pulse) input terminal to which a positive pulse must be applied every time the MT8880 is read/written; (11) IRQ: in the dual tone mode and in the interrupt mode, the terminal changes from high level to low level when a valid DTMF signal is received or ready to send a DTMF signal; when the call processing mode detects the effective signal tone, the end outputs square waves; (12) D0-D3: a data line for writing a command or reading a state; (13) St/Gt: steering Output/Guard Time Output, Output after hysteresis Output/protection. The detected audio pair is saved when the voltage is above VTST while the contents of the output latch are updated. When the voltage is lower than VTST, the chip can re-receive new audio, with the output to Gt having an effect on the lag time constant, which is a function of Est and the voltage applied to St; (14) est: early stepping output, output before lag. When a valid audio pair is detected, (also called Signal condition), the Signal condition is changed into high level, when the Signal condition is not satisfied, the Signal condition returns to low level immediately, the high level on the pin does not necessarily indicate that a DTMF Signal exists, and the voice Signal can also generate the valid audio pair accidentally. More specific correspondence must be determined jointly according to the state of the R/W end, as detailed in table 1 below.

TABLE 1

There are 5 registers inside the MT 8880: a data transmission register TDR, a data receiving register RDR, control registers CRA and CRB and a status register SR. The function of the chip depends on the contents written into the control registers CRA and CRB under the control of the single chip microcomputer, and certain states of the chip can be judged according to the contents read out from the state register SR. When the DTMF signal needs to be received, corresponding control words are written into the control registers CRA and CRB, the chip is set to be in the DTMF mode, and whether a valid DTMF signal is received and decoded can be judged by reading D2 bit in the status register. If so, the contents of the internal "receive data register" are read (from pin D3, D0 of the chip). When the DTMF signal needs to be sent, corresponding control words should be written into the control registers CRA and CRB first, the chip is set to the DTMF mode, and whether sending of a DTMF signal is completed can be determined by reading the D3 bit in the status register. After the transmission is completed, the next number to be transmitted is written into the internal "transmission data register" from D0 to D3. If the chip is set to be in the interrupt mode, whether the DTMF signal is received or sent can be judged by detecting the state of the IRQ end. How the "receive data register" or "transmit data register" is selected, the pins RS0 and R/W should be supplied with the corresponding levels as specified in Table 1. The control registers CRA, CRB and status register all have only 4 bits (bits) and are respectively marked as D0, D1, D2 and D3, and if the control register is to be written or the status register is to be read, the control register and the status register can be written or read through the pins D0 to D3 only by applying corresponding levels to the pin RS0 and the pin R/W according to the specification of table 1.

The ISD4004 series single-Chip voice recording and playing circuit is a new generation product of American ISD company, and as the early product of American ISD company, it adopts Chip-Corder patent technique of ISD company and multistage storage technique, and adopts direct analog quantity storage technique, so that it can truly and naturally reproduce voice and music effect sound, and can avoid quantization noise and metallic sound resulted from quantization and compression of general solid recording circuit. The SPI port control bits are shown in fig. 5. The SPI controls each function of the register control device, such as record playback, voice recording, information retrieval (fast forward), power on/off, start and stop operations, ignoring address pointers, etc., as detailed in table 2 below:

TABLE 2SPI control register

According to the specific design requirements of the telephone remote control system, the system can meet the following functions:

1. the on and off of the electric appliance are controlled in different places through a telephone or a mobile phone, and the state inquiry can be carried out;

2. the controller can realize automatic simulation of the on-hook and the off-hook;

3. before operation, password verification is required, and the security of the system is enhanced;

4. the controller needs to have a voice prompt function to satisfy the intercommunication of information.

As shown in fig. 6 and 12, the ringing detection circuit: when there is no ringing signal on the telephone line, the telephone line is supplied with a dc voltage of about 48V by the telephone exchange, and when the user makes a call, the telephone will ring. The ringing signal is a sine wave of 25 +/-3 HZ, the resonance distortion is not more than 10%, and the effective voltage value is 90 +/-15V. Ringing takes 5 seconds as a period, namely 1s sending and 4s cutting off. In the design, the number of six rings is taken as a preset value, and when the number of rings is more than 6 and no one answers, the system controls automatic simulated off-hook. The telephone ringing signal is isolated by a capacitor C1, the D1 voltage-stabilizing diode is used for stabilizing voltage, and the signal is input to the input port of the photoelectric coupler through R3 after voltage division processing of a resistor R1 and a resistor R2. The ringing signal is output as ringing square wave through the output pin of the optical coupler, the square wave is amplified and sent to the input port of the interrupt counter in the single chip microcomputer for counting, the interrupt is generated after the counting is completed for 6 times, the relay is controlled to simulate off-hook, and the detection and counting work of the whole ringing signal is completed. Wherein C1, Z1, R1 and R2 constitute the converting circuit of the ringing signal jointly, carry on the transformation with the heavy voltage and heavy current in the telephone line, make its voltage and current entering the photoelectric coupler too big, play a role in protecting the photoelectric coupler, R3 is the current-limiting resistance of the photoelectric coupler.

Selecting components: (1) selection of the blocking capacitor C1: the capacitor C1 is a blocking capacitor for filtering direct current and low-frequency signals, and the voltage of a ringing signal is higher, and a 1uf ceramic chip capacitor with withstand voltage of 100V is selected; (2) selection of the resistor RX: the resistors R1, R2 and R3 jointly form a voltage division circuit, 10k, 3.3k and 5.1k are respectively taken, and R3 is a current-limiting resistor of the optocoupler, plays a role in limiting current and provides guarantee for the work of the optoelectronic coupler. The resistors R4 and R5 and the triode form an amplifying circuit which is respectively 200k and 10 k. R6 and LED form the ring indicator, choose 10 Ω resistance here; (3) selection of the zener diode D1: the voltage stabilizing diode D1 is established for the protection of optoelectronic coupling device, and it connects in parallel at the both ends of opto-coupler, and when the positive half cycle of signal adds the both ends that make it switch on at the opto-coupler, when the negative half cycle makes the opto-coupler cut to, can carry out the afterflow through this voltage stabilizing diode to the protection opto-coupler can not damage because of the voltage is too big. Here, a 36V zener diode 1N4753A is selected; (4) selection of a photoelectric coupler U1: the optical coupler is a coupling device of photoelectric signals, and is a device formed by sealing a light emitting diode and a photosensitive triode together. By means of optical signal coupling, various interference pulses mixed in the input switching value are blocked at one side in the input loop. The optocoupler has higher electrical isolation and anti-interference capability, has strong inhibition effect on ground potential difference interference, has strong electromagnetic interference inhibition capability, and has the advantages of high speed, low price, simple interface, small volume and the like, and the optocoupler 4N35 is selected; (5) selection of a triode Q1: q1 and R4 constitute the amplifying circuit, here choose NPN type triode, choose 8050 in this design; (6) selection of the light emitting diode D2: d2 is used as direct reflection of ringing signal, and forms a ringing indicator lamp together with R6, wherein a 5mm yellow LED is selected.

As shown in fig. 7, the analog hook control circuit is mainly controlled by a switch circuit, before the hook is not hooked, a ringing control port is at a high level, the circuit is in a non-working state, after the ringing detection circuit detects six times of ringing, the ringing control port outputs a low level, the base voltage of a triode is changed, the triode Q2 is conducted, a relay is started, and the relay is opened, so that a resistor R10 is connected into a telephone line. Because the access of R10 makes the current in the loop become large, the control circuit sends out analog off-hook signal like the exchange, the exchange responds to the off-hook signal, completes the connection of the telephone line, and completes the action of analog off-hook. After a user inputs an error password or finishes working according to the setting requirement of the user, the level of the control port can be changed to be high through the key, the triode is cut off, and the on-hook is realized. Selecting components: 1. selecting a relay: the relay plays the most important role in the design and is mainly used for realizing the connection of a telephone line and a matched resistor, so that the telephone line is kept after being off-hooked, and in the invention, a relay JRC-4001F (DC5V) is selected, and a 5V direct-current power supply is selected. 2. Selection of diode D2: in order to make the relay work normally, a freewheeling diode is added, and a high-speed switching diode 1N4148 is selected, which is characterized by relatively rapid switching. 3. Selection of a triode Q2: here transistor Q2 functions as a control switch, where a PNP transistor is selected, and transistor 9012 is used in this design. 4. Selection of the light emitting diode D3: d3 is used as direct reflection of whether the analog on-off hook circuit works or not, and forms an analog off-hook indicator lamp together with a resistor R8, wherein a green light-emitting diode of 5mm is selected. Selection of BR 1: BR1 is a rectifier bridge which is used to change the positive and negative of uncertain line power supply in telephone line into fixed positive and negative output, and change the ringing signal of alternating current into pulsating direct current for detection. Here, diodes are not used to form a rectifier bridge, but rectifier bridge block devices are used which are already available on the market. 6. Selection of the resistor RX: the resistors R7 and R9 and the switching transistor jointly form a switching circuit, and 10k and 1k are selected respectively. Resistor R8 and led D3 form an analog off hook indicator, where 1k is selected. Resistor R10 is a matched resistor that maintains the circuit clear after off-hook, where 300 Ω is chosen.

As shown in fig. 8, dtmf (dual Tone Multi frequency) signals are dialing signals of the audio phone, and the dual Tone Multi frequency signal coding technique is easy to identify, has strong anti-interference capability and fast signaling speed, and is more economical and practical than the method of using modem to perform remote transmission, so the dialing method replaces the traditional pulse dialing. The DTMF is composed of two sets of frequency signals of a low frequency set (fb) and a high frequency set (fa), and each digital signal is formed by overlapping any one of the low frequency set and the high frequency set. The invention adopts an MT8880 dual-tone multi-frequency decoding chip, which can realize the sending and receiving of dual-tone multi-frequency signals (DTMF). When DTMF signals are sent, the signals are sent from D0-D3 to a sending data register through a data bus buffer, a programmable row-column counter is controlled, the DTMF signals are synthesized through D/A conversion, and the DTMF signals are sent out from an 8-pin (TONE end) under the action of audio burst door opening control and logic control. When receiving DTMF signals, after analog off-hook, the DTMF signals entering from the telephone line 1 and the telephone line 2 are coupled into an input pin IN-of the MT8880 through a coupling isolation transformer, the DTMF signals are sent to a digital algorithm and code converter for confirmation through an operational amplifier, a dial tone filter, a high-frequency group and a low-frequency group separation band-pass filter, are translated into corresponding 4-bit binary codes, are stored IN a receiving data register, are output to a data bus if necessary, and are sent to a P1 port of STC89C 52. The feedback resistor connected between the input pin IN-and the gain selection terminal GS can adjust the gain of the operational amplifier, and CP is an interrupt request or telephone tone detection output terminal and is connected with an INT1 pin of STC89C 52. The input DTMF signal is coupled into the MT8880 through an isolation transformer, the MT8880 receives and decodes the input DTMF signal, the output four-bit parallel binary data is directly connected with the ports P1.0-P1.3 of the single chip microcomputer, and the MT8870 informs the CPU to take away the data when receiving the effective DTMF signal and solving the correct BCD data. The CPU reads data from port P1, reads P1.0-P1.3 data into internal register unit, and judges the read value to obtain the input command of remote controller. And selecting corresponding components according to the working principle and characteristics of the coding and decoding circuit to design a circuit schematic diagram. The invention has the following components: 1. selecting an audio isolation coupler: the audio frequency output often has AC interference noise, the horn has AC noise, the reason is caused by common ground, because the signal source ground and the horn power amplifier ground have potential difference, and the two grounds are connected together to generate AC noise, the better method is to adopt 1:1 audio frequency coupling isolation transformer to separate the ground, thereby restraining the noise brought by the common ground, and the coupling isolation has no influence on the sound quality. In the embodiment of the invention, the selected impedance is 600: a 600 ohm audio transformer; 2. selection of a triode Q3: the signals output by the MT8880 and the voice signals must be amplified by an amplifying circuit and then coupled to the telephone line through an audio coupler. The Q3 plays a role in amplification, and an NPN 8050 triode is selected for amplification; 3. selection of a crystal oscillator X1: the chip external crystal oscillator X1 selects 3.579545 MHZ; 4. selection of the resistor RX: the peripheral circuitry of MT8880 employs a number of resistors, the parameters of which are given below. R12 and R13 are input balance resistors and are both 100k, R14 is an output balance resistor, 300k is taken, R15 is 4.7k, R16, R17 and R26 are 10k resistors, R18 is 51k resistor, and R19 is 120 omega resistor. 5. Selection of the capacitance CX: besides a large number of resistors, the MT8880 peripheral circuit also applies a large number of capacitors, which have a blocking function and a filtering function, and the parameters of each capacitor are as follows: c2, C4, C6 and C13 select 0.1 muF capacitance, C3 selects 30PF capacitance, C5 is 0.01 muF, C7 and C8 select 22NF and 22PF capacitance respectively.

The voice prompt module is used for prompting a user to operate the controller, namely when the user connects the control system through a fixed telephone network or a mobile telephone network, the voice circuit prompts the user to input a password and a control instruction so as to remotely control the household appliance. Therefore, the chip selected by the voice circuit must have three functions: the sectional recording, playback and addressable telephone remote control system uses the voice prompting circuit to realize the communication between the user and the system. The voice prompting circuit stores a plurality of sections of system prompting tones in advance, and after the 89C52 central processing unit circuit judges the DTMF signals sent by the user, the voice prompting circuit is addressed, and corresponding prompting tones are played, so that information is fed back to the user to prompt the user about how to operate in the next step. In the system, a voice chip ISD4004 is selected to complete voice prompt work. After receiving DTMF signal sent by far-end user, the system makes addressing playback for voice circuit. For example, when the system receives a user password signal of "1234 #" sent by the user, if the password is correct, the voice prompt is addressed and played: the password is correct, please operate, the electric appliance numerical value is input, the # key is pressed on, the 0 key is pressed, the left key is pressed, the back is returned, if the password is wrong, whether the number of times of the mistake is more than 3 is judged, if the number of times of the mistake is not more than 3, the voice prompt is played by addressing: "password error please re-enter". If the error times are more than 3, addressing and playing the voice prompt: "for no-go, your number of errors has reached the maximum limit" and then hang up automatically.

Because the ISD4004 works under the control of the single chip microcomputer, the single chip microcomputer must realize the working mode of simulating the SPI bus, and simultaneously inquire the working state of the ISD4004 (for example, whether the operation reaches the end of a certain address, and whether the memory overflows), 6 IO ports of the single chip microcomputer can be selected to be respectively connected with the MISO, the MOSI, the SCLK, the INT, the RAC and the CS of the ISD4004, wherein the CS is used as a chip selection signal of a device, and the MISO, the MOSI, the SCLK and the INT are used for data communication of the single chip microcomputer, and control the functions of voice prompt playing, inquiry and the like of the ISD 4004. The schematic diagram of the voice prompt circuit is shown in fig. 9, and the components are selected as follows: 1. selection of audio sockets U6 and U7: the audio socket is used as a voice input end and a voice output end, the voice input end can be connected with a computer through an audio cable, recorded voice is input into a voice circuit to be stored, and the voice output end can be connected with an earphone to enable a user to hear recorded voice signals. 2. Selection of a triode Q4: the triode Q4 is used for forming an amplifying circuit, amplifying the voice signal sent by the microphone, sending the amplified voice signal to the ANAIN + end of the ISD4004, sending the voice signal to the ISD4004, and selecting the triode NPN 9014 to complete corresponding amplification work. 3. Selection of the resistor RX: a number of resistors were used in the ISD4004 periphery and the parameters of these resistors were as follows: the resistances of the three resistors R20, R23 and R24 are all 10k, 100k of resistors R21 are selected, and 330 omega of R22. 4. Selection of the capacitance CX: the ISD4004 peripheral circuit uses a plurality of capacitive elements selected from the following: c9, C10, C11, C12, C14 and C15 all select ceramic chip capacitors of 0.1 muf, and C16 selects electrolytic capacitors of 220 muf.

As shown in fig. 10, the household appliance control pin connection circuit is formed by discrete components, and includes a set of relay and protection diode, and the single chip microcomputer controls the on-off state of the relay by setting the

corresponding position

1 or 0 of the IO port, so as to control the household appliance. Because the number of I/O ports of the single chip microcomputer is limited, in order to save ports, the 4LS138 is adopted to expand and control the line number of the relay of the household appliance so as to realize the remote operation of the household appliance, thus saving the IO ports of the single chip microcomputer and fully playing all functions of the system. Selecting components: the most important control circuit is the relay switch control part, and the use of the relay switch has been described in the circuit design of the analog pick-up and hang-up, and the used principle is similar to the relay switch, so that the detailed description is not needed. The 74LS138 decoder is described with emphasis here. 74LS138 is a 3-line to 8-line decoder that decodes binary codes at address terminal A, B, C at low levels at the corresponding output terminals Y0 through Y7 when one gate terminal E1 is high and the other two gate terminals E2 and E3 are low. Such as: when CAB is 000, the output terminal of Y0 outputs a low level signal. The truth table is shown in table 3:

TABLE 3 truth table

As shown in fig. 11, the LCD1602 liquid crystal is also called 1602 character type liquid crystal, which is a dot matrix type liquid crystal module specially used for displaying letters, numbers, symbols, and the like. The character display device consists of a plurality of dot matrix character bits such as 5X7 or 5X11 and the like, each dot matrix character bit can display a character, a dot pitch interval exists between every two bits, and an interval also exists between every two lines, so that the functions of the character interval and the line interval are achieved, and the character display device cannot well display a graph. The LCD1602 is a liquid crystal module that displays 16X2, i.e., can display two lines of 16 characters each (displaying characters and numbers).

In the system, the ringing signal is mainly counted, and the ringing signal is characterized by a 25HZ sinusoidal signal with a period of 5 seconds, 1s on and 4s off. Therefore, about 25 pulse signals can be generated each time, and by utilizing the characteristic, a ringing counting program can be designed so as to realize automatic simulation of off-hook after a certain number of times of ringing and no-one answering. The flow chart is shown in fig. 12.

The password detection is designed for the safety performance of a true and false system, so that only a legal user can use the system, and other people are not allowed to destroy the system, therefore, the establishment of the password verification module is an excellent choice for the user to have high system safety.

The design idea of the invention is that a user searches a position space in the single chip microcomputer in advance to store a preset password, and then judges whether an operator can carry out the next operation according to the password input by the user, wherein the operator has three chances each time, and the three chances are incorrect, so that the single chip microcomputer automatically hangs up. The password detection flow chart is shown in fig. 13.

In the system general tuning process, dialing a telephone number through a mobile phone, recording the ringing frequency of the telephone, observing whether the telephone automatically picks up the telephone after ringing for six times, and then after the system simulates picking up the telephone, seeing whether an off-hook signal indicator lamp is on or not, if yes, indicating that no problem exists in the simulated picking up. After off-hook, the time is input, and the time for inputting the number is required to be paid attention, and the system is ready to be decoded. So that the next operation can be completed. Whether the voice recording and input can be verified through the external loudspeaker in the voice debugging, the debugging of the liquid crystal module can be debugged through the external keys, and the good effect can be obtained only by controlling the mobile phone keys.

The invention relates to an intelligent home remote control system based on a telephone network and a control method thereof, which have the advantages that: the control system mainly comprises a ringing detection module, a DTMF dual-tone frequency coding and decoding module, an analog pick-up and hang-up module, a voice prompt module and a display module, and realizes a remote control function under the control of a main controller of the system. The telephone lines are connected with each other locally, so that the telephone can be fully utilized, the remote control distance can span provinces and cities, even countries, and the telephone belongs to a duplex communication mode, so that the telephone has a good application background when being used for remote control. The control system can control (switch on and off) the household appliances in different places through the telephone network, and is suitable for occasions such as families, shops and the like; the control system can realize automatic simulation of pick-up and hang-up through the ringing detection module so as to realize communication between the two parties; the control system needs to set password verification, and can realize the functions of user identity verification, online password modification, password storage and the like; the control system has a voice prompt function, so that a user has voice prompt when performing various operations, and the operation of the user is facilitated; the control system is provided with a time display module, so that the operation time can be recorded in real time.

Claims

1. The intelligent home remote control system based on the telephone network is characterized by comprising a ringing detection module and a DTMF dual-tone frequency coding and decoding module which are respectively connected in parallel at two ends of a home telephone, wherein the output end of the ringing detection module is connected with a main controller; the signal sending part and the receiving part of the DTMF dual-tone encoding and decoding module are both connected with the main controller and are used for realizing sending and receiving of dual-tone multi-frequency signals DTMF; the main controller is connected with the input end of the analog on-off hook module, and the analog on-off hook module is connected with the telephone in series to realize the on-off control of the circuit; the main controller is also connected with a voice prompt module, the voice prompt module is connected with a power amplification circuit, the power amplification circuit is connected to a telephone line in parallel, and the voice prompt module prompts a user to operate the controller; the clock module in the main controller is connected with the display module, and the display module is used for realizing state display, time display and online modification of the electric appliance; and a control pin on the main controller is connected with the electric appliance and used for controlling the on-off and state of the electric appliance.

2. The intelligent home remote control system based on the telephone network as claimed in claim 1, wherein the main controller adopts STC89C52 single chip microcomputer.

3. The intelligent home remote control system based on the telephone network according to claim 1, wherein the circuit structure of the ringing detection module is: a capacitor C1, a resistor R1 and a resistor R3 are sequentially connected in series on a telephone line 1, a resistor R2 and a voltage stabilizing diode D1 are sequentially connected in parallel between the telephone line 1 and the telephone line 2 between the resistors R1 and R3, the other ends of the resistor R3 and the voltage stabilizing diode D1 are respectively connected to the input end of a photoelectric coupler U1, a telephone ringing signal is isolated through the capacitor C1, the voltage of the voltage stabilizing diode D1 is stabilized, and the signal is input to the input port of the photoelectric coupler U1 through R3 after the voltage division processing of the resistor R1 and the resistor R2; the output end of the photoelectric coupler U1 is connected with an amplifying circuit consisting of resistors R4, R5 and a phototriode Q1, and the other end of the amplifying circuit is connected with an input pin of an interrupt counter in the main controller; a ringing indicator lamp is also connected in parallel between the photoelectric coupler U1 and the main controller, and the ringing indicator lamp is formed by connecting a resistor R6 and a light-emitting diode D2 in series.

4. The intelligent home remote control system according to claim 1, wherein the DTMF dual tone codec module employs an MT8880 dual tone multi-frequency decoding chip to implement sending and receiving of dual tone multi-frequency signals DTMF.

5. The intelligent home remote control system based on the telephone network according to claim 1, wherein the circuit structure of the analog pick-up and hang-up module is as follows: the telephone line 1 is connected with the upper port of a rectifier bridge BR1, and the right port of the rectifier bridge BR1 is connected with a matching resistor R10; the telephone line 2 is connected with a lower port of a rectifier bridge BR1, a relay is connected between the telephone line 2 and the rectifier bridge BR1, the lower end of the relay is connected with a diode D2 in parallel, the other end of the diode D2 is connected with an emitter of a triode Q2, a collector of the triode Q2 is connected with a resistor R10 and then is grounded, a base of the triode Q2 is connected with the resistors R7 and R9 in parallel to form a switch circuit, the switch circuit is also connected with an analog off-hook indicator light consisting of the resistor R8 and a light emitting diode D3 in parallel, and the other end of the light emitting diode D3 is connected with an analog off-hook control pin on the main controller.

6. An intelligent home remote control system based on a telephone network as claimed in claim 1, wherein the voice prompt module adopts a voice chip ISD 4004.

7. The intelligent home remote control system based on the telephone network as claimed in claim 1, wherein the display module adopts an LCD1602 liquid crystal display.

8. The method according to any one of claims 1 to 7, wherein when a user needs to control the home appliances, the user can dial a home phone number, the switch sends a ring signal to the home phone, when a ring signal comes in, the ring detection circuit of the ring detection module of the system receives the ring signal and converts it into a pulse signal, and sends the pulse signal to the main controller through the timer counting interrupt port of the main controller for counting operation, when the counted ring number reaches a set number, no one answers, an interrupt application is issued to the main controller, and the main controller responds to an interrupt request to make the control port of the analog hook module low, and starts the analog hook circuit, realizing automatic off-hook; after a circuit is connected, the main controller enables a voice chip connecting end of the voice prompt module to be at a low level, sends a control command to start a voice prompt circuit, transmits voice prompt information to a telephone line to prompt a user to input a password, converts a dual-tone signal into a corresponding binary number through a decoding circuit of the DTMF dual-tone encoding and decoding module, sends the binary number into the main controller to carry out password verification, controls the voice prompt module to send voice prompt operation if the password is correct, prompts re-input if the password is wrong, and controls a control port of the analog pick-up and hang-up module to be at a high level to cut off circuit communication and automatically hang up if the password is wrong; the display module is used for realizing state display, time display and online modification of the electric appliance and recording operation time in real time; after the password is correct, the state query of the control equipment and the equipment can be selected under the voice prompt of the voice prompt module, if the control operation of one electric appliance is finished and another electric appliance needs to be controlled, the operation needs to be returned by pressing an 'X' key, and if the operation does not need to be carried out or is finished, the operation is bound by pressing a '#' key, and the remote control operation is finished.