CN212727040U - Multimode emergency broadcast terminal - Google Patents

Abstract

The utility model discloses a multimode emergency broadcast terminal, which comprises a main control chip MCU; the main control chip MCU is respectively and electrically connected with the NB-IoT module, the audio module, the 4G module, the FPGA chip, the network chip, the FM demodulation chip and the RFID tag; the FM demodulation chip is electrically connected with the audio-low pass filtering module and the audio switching module in sequence; the audio switching module is respectively electrically connected with the coding and decoding chip, the audio detection chip, the audio module, the local sound source and the shunt; the shunt is respectively electrically connected with the FM modulation module and the audio power amplifier; the FPGA chip is connected with the TS mediation unit.

Description

Multimode emergency broadcast terminal

Technical Field

The utility model belongs to the technical field of emergent broadcast terminal equipment, concretely relates to multimode emergent broadcast terminal.

Background

With the establishment and the promulgation of the national emergency broadcasting system construction standard, the village and village construction of emergency broadcasting is pushed all around the country, and at present, the national emergency broadcasting forms a multi-network publishing, multi-channel transmission and central-to-local controllable linkage broadcasting mode. The broadcast and television transmission networks are optimized and perfected by executing a unified technical standard system, the broadcast and television series products are upgraded, and the public culture service is improved, so that the stage achievement is achieved. But emergency broadcast coverage in remote mountainous areas is difficult due to rural economic laggard.

The existing terminal deployment can not deploy terminal equipment according to different transmission networks and coverage areas according to local conditions, so that the cost investment and the later operation and maintenance cost are increased.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to the above-mentioned among the prior art not enough, provide a multimode emergency broadcast terminal to solve current terminal deployment, can not carry out terminal equipment's deployment according to different transmission network and coverage area according to local conditions, so that increase cost input and later stage operation maintenance cost's problem.

In order to achieve the purpose, the utility model adopts the technical proposal that:

a multimode emergency broadcast terminal comprises a main control chip MCU; the main control chip MCU is respectively and electrically connected with the NB-IoT module, the 4G module, the FPGA chip, the network chip, the FM demodulation chip and the RFID tag; the FM demodulation chip is electrically connected with the audio-low pass filtering module and the audio switching module in sequence; the audio switching module is respectively and electrically connected with the coding and decoding chip, the audio detection chip, the audio module, the local sound source and the shunt; the shunt is respectively electrically connected with the FM modulation module and the audio power amplifier; the FPGA chip is connected with the TS mediation unit.

Preferably, the MCU of the main control chip is an STM32F-429xT chip

Preferably, the NB-IoT module embeds an NB-IOT chip ML 2510.

Preferably, the 4G module houses a U402 SIM7600CE chip.

Preferably, the encoding and decoding chip is a U403 NAU88U10 chip; the U403 NAU8810 chip is connected to the 4G module I2C.

Preferably, the TS mediation unit comprises a demodulation module ATBM 8869.

Preferably, the network chip model is W5200 network chip.

The utility model provides an emergent broadcast terminal of multimode has following beneficial effect:

the utility model discloses in terminal equipment deployment, according to local conditions, according to different transmission networks and coverage area carry out terminal equipment's deployment, to the rural area that is nearer apart from the terminal, deploy FM/IP/TS/4G multimode or single mode and receive emergent broadcast terminal; IoT terminals with relatively far coverage areas are deployed for rural areas that are far away.

Drawings

Fig. 1 is a schematic block diagram of a circuit of a multimode emergency broadcast terminal.

Fig. 2 is an NB-IoT application circuit.

Fig. 3 shows a 4G application circuit.

Fig. 4 is a 4G audio decoding circuit.

Fig. 5 shows a DTMB/DVB-C reception demodulation circuit.

Fig. 6 is an application circuit of the network chip.

Fig. 7 is a circuit diagram of an audio low-pass filter.

Fig. 8 is a circuit diagram of audio signal switching.

FIG. 9 is a circuit diagram of an audio codec.

Detailed Description

The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and various changes may be made apparent to those skilled in the art within the spirit and scope of the present invention as defined and defined by the appended claims.

According to an embodiment of the present application, referring to fig. 1, the multimode emergency broadcast terminal of the present solution includes a main control chip MCU; the main control chip MCU is respectively and electrically connected with the NB-IoT module, the audio module, the 4G module, the FPGA chip, the network chip, the FM demodulation chip and the RFID tag; the FM demodulation chip is electrically connected with the audio-low pass filtering module and the audio switching module in sequence; the audio switching module is respectively electrically connected with the coding and decoding chip, the audio detection chip, the audio module, the local sound source and the shunt; the shunt is respectively electrically connected with the FM modulation module and the audio power amplifier; the FPGA chip is connected with the TS mediation unit.

The hardware device described above is described in detail below.

STM32F-429xT is selected as a main control module by the main control chip MCU.

Referring to fig. 2, the NB-IoT module is internally provided with an NB-IoT chip ML2510, the chip ML2510 is located in an NB-IoT application circuit, and capacitors C14, C15, C16 and C17 in the circuit are power filter capacitors for filtering out ac components, so that the output dc is smoother and the stable operation of the chip is guaranteed.

The Led1 chip is turned on to indicate that the chip is working normally (the chip is started up inside), and the resistor R2 is used to limit the current from being too large and damaging the Led.

The TVS1B (ESDA6V1) antistatic device has the functions of voltage overvoltage protection and voltage reverse isolation, and plays a role in protecting the SIM card.

The 6-pin SIM1 socket is used for inserting an NB-IOT card in practical use.

The main control chip STM32F-429xT and the ML2510 module adopt serial port communication, and the resistors R11 and R12 can enhance electromagnetic compatibility and prevent signal reverse interference.

The capacitor C6 is used as a power supply filter capacitor of the SIM card, and can effectively reduce the phenomenon of card dropping caused by interference.

The communication between the NB-IOT chip ML2510 and the SIM card can improve the anti-interference capability, effectively reduce the interference and ensure the communication quality by using the resistors R5, R6 and R7 and the capacitors C3, C4 and C5.

Referring to fig. 3, the 4G module is built in with a U402 SIM7600CE chip, and the codec chip is a U403 NAU8810 chip; the U403 NAU8810 chip is connected to the 4G module I2C.

FB401, D401, C411, C412, C416, C405, C408, C409 in the application circuit of 4G module are used for stabilizing the supply voltage, filtering out the clutter, prevent the excessive pressure, ensure chip job stabilization.

And R407, R409 and Q401 form a 4G chip switching circuit, and the 4G chip is controlled to be switched on and switched off by a main control chip MCU.

R408, R411, Q402, C401 constitute 4G chip reset circuit, through the hard reset of main control chip control 4G chip.

F403 is a 4G chip antenna interface and is externally connected with an antenna, and excellent signal quality is provided.

R415, R416, R413, Q404 and LD402 form a 4G chip working state display circuit, and the working state of the chip is judged by the display state of the light emitting diode LD 402.

R412, R414, R410, Q403 and LD401 constitute a 4G chip network state display circuit, and whether the chip is connected to the network or not is judged by the display state of the light emitting diode LD 401.

The U401 is used for level conversion of serial port communication between the 4G chip and the main control chip, matches respective serial port voltage, and prevents the chip from being damaged due to signal interference and voltage mismatching.

CN401 is SIM card socket for inserting 4G-SIM card. The C401 and the C402 are used as power supply filter capacitors of the SIM card, so that the phenomenon of card dropping caused by interference can be effectively reduced; in the communication process of the 4G chip and the SIM card, the resistors R401, R402 and R406 and the capacitors C403, C404 and C407 improve the anti-interference capability, effectively reduce the interference and ensure the communication quality.

Referring to fig. 4, U403 is a codec chip for audio, mainly used for audio codec during telephone insertion. Wherein R417 and R418 are used as pull-up resistors for I2C communication, so that the driving capability and the anti-interference capability of an output pin are enhanced; the C413, the C414, the C415, the C420 and the C421 filter out noise waves, enhance the anti-interference capability and improve the stability of the chip; the capacitors C422, C423 and C427 are used for isolating direct current components in audio in-out process, and improving audio quality.

The DTMB/DVB-C signal is connected with the MCU through the TS demodulation unit, the FPGA chip and the main control chip in sequence.

Referring to fig. 5, the DTMB/DVB-C receiving and demodulating circuit, the tuner U5 receives the DTMB/DVB-C signal, the demodulation is completed through the U6 demodulation module ATBM8869, and the TS signal is sent to the 144-TQFP-ep2C5t144C8n-FPGA chip in parallel. And the FPGA completes demultiplexing of the TS stream, extracts audio data and SI information according to the specified PID and table id, and sends the audio data and the SI information to the main control chip for decoding, playing and analyzing.

The FPGA and the main control chip communicate with each other through the SPI and the I2C. The I2C interface is mainly used for completing related configuration of demultiplexing, including PID of audio; PID, table id of SI, etc. The communication speed can reach 200Kbps, and the configuration content can be read and written.

The SPI interface is mainly used for finishing the transmission of data from the FPGA to the main control chip.

And after the audio data and the TS packet are received, the data is indicated to be ready through the interrupt pin, and the main control chip reads the audio data of the corresponding channel from the FPGA through the SPI interface to decode and play.

And after the section is received, indicating that the data is ready through an interrupt pin, and reading the SI data of the corresponding channel from the FPGA for analysis by the main control chip through the SPI interface.

Network chip circuit

Referring to fig. 6, U10 is a network chip, A3 is an RJ45 network interface, and U21 provides protection for sensitive components, so as to enhance the anti-interference capability of U10 and RJ45 in the communication process.

C53, C54, C55, C56, C57, C58, C59, C60, C61, C62, C63, FB4 and FB5 stabilize power supply voltage, filter noise waves and guarantee stable chip operation.

Y3, R36, C51 and C52 form a crystal oscillator driving circuit, and R36 is used for impedance matching, so that the crystal oscillator driving circuit is in a good working condition.

The functions of the R42, the R43, the R44, the R45, the C64 and the C65 are to enhance the anti-interference capability in the communication process of the network chip.

R32, R33, R37, R38 and R39 are used as external pull-up resistors of the network chip and provide reference voltage for the operation of the network chip.

R30, R31 are pull-up resistance, improve the driving ability, are used for the network interface status indicator lamp to show. The R47 and R46 function as current limiting to prevent the network indicator lamp from being damaged due to overlarge circuit.

Referring to fig. 7, the purpose of the audio low pass filter circuit, plus the low pass filter, is to allow electronic filtering where signals below the cutoff frequency pass, but signals above the cutoff frequency do not. Wherein, R61, C67, C68, R62, C66, R63, R64, R65, C71, C72 and U7-2 form a 4-order Chebyshev type low-pass filter, and high-frequency components above 15K are filtered out, so that the audio signal-to-noise ratio is improved.

R40 is the DC power input from the front stage to the ground, C64, C65, C69 and C70 are the power filter capacitors of plus-minus 5V, C73 and C76 are the audio signal input-output coupling capacitors, and R60 has the functions of isolation and signal attenuation.

Referring to fig. 8, the audio signal switching circuit and the audio signal switching module are controlled by the main control chip (to control pins 9 and 10), so that the device receives the switching between the upper layer and the local broadcast audio.

The FM demodulated audio is coupled by a C130 after being output by a low pass filter, and then is output to an audio switching module X0 through R160 and C132, the other is output to an audio switching module Y0 through R161 and C131, the FM demodulated audio is respectively output through a control audio switching module X, Y of the main control chip, the X output is output to an FM modulation module through C134, R168, R166 and C135, is output to an FM power amplification module through C134, R168, R167 and C136, and the Y output is output to a coding and decoding chip through C133.

The 4G telephone inter-cut audio is coupled with one path through C126 and is output to an audio switching module X1 through R158 and C122, the other path is output to an audio switching module Y1 through R157 and C121, the audio switching modules X1 and Y1 are controlled by a main control chip to respectively output, the X output is output to an FM modulation module through C134, R168, R166 and C135, is output to an FM power amplification module through C134, R168, R167 and C136, and the Y output is output to a coding and decoding chip through C133.

The codec chip inputs audio, namely, the audio decoded by IP and DTMB/DVB-C, the audio is coupled by C125 to an audio switching module X2 through R156 and C120 after being output, the audio is coupled by the other path of the audio switching module Y2 through R155 and C119, the audio is respectively output through the audio switching modules X2 and Y2 controlled by the main control chip, the X output is transmitted to an FM modulation module through C134, R168, R166 and C135, and is transmitted to an FM power amplifier module through C134, R168, R167 and C136. Because IP and DTMB/DVB-C communicate with main control chip, the decoded audio is digital audio, and need not encode the analog audio again through the encoding and decoding chip.

The local audio input is coupled by C129, one path is connected to an audio switching module X3 by R162 and C128, the other path is connected to an audio switching module Y3 by R163 and C127, the local audio input is respectively output by the audio switching modules X3 and Y3 controlled by the main control chip, the X output is connected to an FM modulation module by C134, R168, R166 and C135, and is connected to an FM power amplifier module by C134, R168, R167 and C136, and the Y output is connected to a codec chip by C133.

The audio switches 6, 7 and 8 pins to the ground, 16 pins to the power supply 12V, and the capacitors C42 and C138 are power supply filter capacitors.

Referring to fig. 9, an audio codec circuit, U20 audio codec chip VS1063a, is an easy-to-use multi-function encoder capable of encoding and decoding multiple audio formats.

Y1, C29, C32 and R6 form a crystal oscillator driving circuit, and R36 is used for impedance matching, so that the crystal oscillator driving circuit is in a good working condition.

Part of pins of the coding and decoding chip are connected with a resistor R4 to the ground, so that the unused part of pins are ensured to be low level, and the interference and the unstable work are avoided.

The capacitors C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25 and C26 stabilize power supply voltage, filter noise waves and guarantee stable chip operation.

The C33 functions as a filter to filter out external interference information.

C27 and C28 filter out the DC component in the decoded audio output, and improve the audio quality.

The audio input interfaces C30 and C31 are used for filtering direct current signals in input audio; r5, R7 are used for impedance matching with the chip interior, play the role of protection input.

The working principle of the scheme is as follows:

when equipment receives a superior FM broadcast RF signal, a superior audio signal is demodulated through an FM demodulation chip, the audio signal filters incoherent interference components above 15K through an audio-low pass filter, one path of the audio signal is modulated and output through a shunt after passing through an audio switching module, and the other path of the audio signal is output through a coding and decoding chip, a main control chip and a network chip IP; the FM demodulation chip and the FM modulation module are respectively communicated with the main control chip through I2C, and the superior control instruction forwarding or the local broadcast control instruction broadcasting is realized according to the priority broadcasting requirement.

When the equipment receives a superior IP signal, the network chip communicates with the MCU through the SPI, reads audio data of a corresponding channel for decoding, sends the audio signal to the audio switching module through the editing code chip, and modulates and outputs the audio signal through the shunt; and reading and analyzing SI data of the corresponding channel, and realizing superior control instruction forwarding according to priority playing requirements.

When the device receives a superior DTMB/DVB-C radio frequency signal, the device communicates with a main control chip through SPI and I2C through an FPGA chip by a TS demodulation unit (a tuner and a TS demodulation chip), reads audio data of a corresponding channel from the FPGA, decodes the audio data, sends the audio signal to an audio switching module by an editing code chip, modulates and outputs the audio signal by a splitter, and outputs the audio signal by a network chip IP; and reading the SI data of the corresponding channel from the FPGA for analysis, and realizing the forwarding of the superior control instruction according to the priority playing requirement.

When the equipment receives a 4G signal, the 4G module is communicated with the main control chip through I2C and is communicated with the audio module to execute I2C, the audio module demodulates the audio signal and sends the audio signal to the audio switching module to be output by modulation of a splitter, and one path of audio signal is output by IP through the coding and decoding chip, the main control chip and the network chip; and realizing the telephone inter cut of the current level according to the priority playing requirement.

When the device receives an NB-IoT signal, the NB-IoT module is communicated with the main control chip through I2C, an audio signal is demodulated through the coding and decoding chip and sent to the audio switching module to be modulated and output through the shunt, and one path of the audio signal is output through the coding and decoding chip, the main control chip and the network chip IP; and according to the priority playing requirement, the superior control instruction forwarding is realized.

The RFID tag realizes batch equipment production and warehousing. The RFID tag and the main control chip establish a read-write relationship, the RFID tag antenna generates induced current through electromagnetic induction, the induced current drives the RFID chip circuit, the chip circuit sends identification information stored in the tag to the main control chip through the RFID tag antenna, and the main control chip sends the data to the emergency broadcast front-end platform through the NB-IoT module and the antenna and then sends the received identification information to the emergency broadcast front-end platform, so that management of emergency broadcast equipment is realized.

The audio detection chip and the power detection chip are respectively connected with the main control chip to realize real-time detection and feedback of the audio output amplitude of the equipment, and the power supply voltage of each module of the equipment is detected and fed back in real time and is used as a feedback channel through NB-IoT.

The audio power amplifier is respectively connected with the audio switching module and the control unit, the control unit is connected with the main control chip, and when the upper-level broadcast information is received, audio sound amplification broadcasting is carried out according to the priority playing requirement.

The safety module is integrated with the command receiving and sending systems of all levels of village and village rings to realize signature and verification of emergency broadcast commands; the safety module integrated with the village terminals realizes the verification of emergency broadcast instructions.

Emergency broadcasting and internet of things are mainly focused on urban municipal administration supervision in urban application deployment, the administrative, law enforcement and management capabilities of governments are improved, and solid data support is provided for issuing and executing administrative decisions. Because urban emergency broadcast coverage is easy, wired IP and wireless FM transmission are generally adopted in equipment application deployment.

Emergency broadcasting and internet of things are mainly focused on sound propagation, geological disaster forecast, public health prevention and control, environmental protection, agricultural science popularization knowledge propaganda and the like in rural application deployment. Meanwhile, powerful technical support is provided for the improvement of the country happiness, the treatment capability and the treatment system of all levels of government departments and the rural broadcast global coverage.

While the present invention has been described in detail with reference to the embodiments, the scope of the present invention should not be limited to the embodiments. Various modifications and changes may be made by those skilled in the art without inventive step within the scope of the appended claims.

Claims (7)

1. A multimode emergency broadcast terminal, characterized by: the system comprises a main control chip MCU; the main control chip MCU is respectively and electrically connected with the NB-IoT module, the 4G module, the FPGA chip, the network chip, the FM demodulation chip and the RFID tag; the FM demodulation chip is electrically connected with the audio-low pass filtering module and the audio switching module in sequence; the audio switching module is respectively and electrically connected with the coding and decoding chip, the audio detection chip, the audio module, the local sound source and the shunt; the shunt is respectively and electrically connected with the FM modulation module and the audio power amplifier; and the FPGA chip is connected with the TS mediation unit.

2. The multimode emergency broadcast terminal of claim 1, wherein: the MCU of the main control chip is an STM32F-429xT chip.

3. The multimode emergency broadcast terminal of claim 1, wherein: the NB-IoT module is built-in with an NB-IOT chip ML 2510.

4. The multimode emergency broadcast terminal of claim 1, wherein: the 4G module is internally provided with a U402 SIM7600CE chip.

5. The multimode emergency broadcast terminal of claim 1, wherein: the coding and decoding chip is a U403 NAU88U10 chip; the U403 NAU8810 chip is connected with the 4G module I2C.

6. The multimode emergency broadcast terminal of claim 1, wherein: the TS demodulation unit comprises a demodulation module ATBM 8869.

7. The multimode emergency broadcast terminal of claim 1, wherein: the model of the network chip is W5200 network chip.

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