Communication circuit and communication module applicable to smart visual scene

Abstract

The invention discloses a communication circuit and a communication module applicable to an intelligent visual scene, and relates to the technical field of communication. In the communication circuit, a baseband chip controls a first selection circuit to generate an analog detection signal by sending a selection signal; and the detection signal is superposed with an actual detection signal generated when the SIM card is inserted into the corresponding SIM card seat and then is fed back to the baseband chip, so that the baseband chip confirms whether communication with the corresponding SIM card is needed or not. And meanwhile, the second selection circuit is controlled through the selection signal to switch the communication channel between the baseband chip and the corresponding SIM card seat to enter a conduction state. According to the method, the baseband chip is communicated with the corresponding SIM card only when the baseband chip is communicated with the corresponding SIM card, and software control logic and a hardware channel are synchronously switched, so that the condition of SIM card data confusion caused by software control errors in the process of repeatedly switching the SIM cards is avoided, and the stability of system operation is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication circuit and a communication module that can be applied to smart vision scenarios. Background Art

[0002] In some important areas, cameras and other visual modules are usually set up to monitor the area, so that the staff can trace the important events that have occurred in the area in the past. For some remote areas, the cost of setting up long cables alone is high, so cameras are usually combined with communication modules to transmit images of the monitored area to the base station through wireless communication.

[0003] Since the signal in the edge area is generally poor, and the signal strength in different areas is different for different communication services, it is generally adopted to install multiple SIM cards that can provide different communication services in the communication module to ensure that the visual modules such as cameras can stably transmit the image of the monitored area to the base station in real time. In the existing multi-SIM card communication module, the SIM card is usually switched only by software to wake up the SIM card to be used and keep other SIM cards asleep, so as to achieve the switching of SIM cards, and will not cut off the communication channel between the sleeping SIM card and the chip. In some areas where the signal strength provided by the communication service changes repeatedly, the software needs to frequently issue switching instructions to achieve the switching of SIM cards. Since each SIM card can transmit data with the chip at the moment of being awakened, it is easy to confuse the configuration data of multiple SIM cards, and the interrupt configuration of the SIM card is wrong, affecting the normal operation of the system. Summary of the invention

[0004] The main purpose of this application is to provide a communication circuit and a communication module that can be applied to smart vision scenarios, aiming to solve the technical problem of how to make the baseband chip communicate more stably with one of the SIM cards in dual-card single-standby mode.

[0005] To achieve the above-mentioned object, the present application provides a communication circuit applicable to a smart visual scene, the communication circuit comprising: a first selection circuit, a second selection circuit and a baseband chip; The first output end of the baseband chip is connected to the control end of the first selection circuit and the control end of the second selection circuit, the first communication end of the baseband chip is connected to the first end of the second selection circuit, the second end of the second selection circuit is connected to the first communication end of the first SIM card holder, the third end of the second selection circuit is connected to the first communication end of the second SIM card holder, the first output end of the first selection circuit is connected to the detection end of the first SIM card holder and the first input end of the baseband chip, and the second output end of the first selection circuit is connected to the detection end of the second SIM card holder and the second input end of the baseband chip; the first SIM card holder and the second SIM card holder send actual detection signals to the baseband chip when the SIM card is connected; The first selection circuit is used to send a corresponding analog detection signal to the baseband chip based on a selection signal sent by the baseband chip; The second selection circuit is used to connect the communication channel between the baseband chip and the first SIM card holder or the second SIM card holder based on the selection signal; The baseband chip is used to communicate with the corresponding SIM card through the corresponding communication channel based on the simulated detection signal and the actual detection signal.

[0006] In one embodiment, the first selection circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first NMOS transistor, a first PMOS transistor and a first N-type triode; The first output end of the baseband chip is connected to the first end of the first resistor, and the second end of the first resistor is respectively connected to the first end of the second resistor and the base of the first N-type transistor; the emitter of the first N-type transistor and the second end of the second resistor are grounded, the collector of the first N-type transistor is respectively connected to the second end of the third resistor, the first end of the fourth resistor and the detection end of the second SIM card holder, the second end of the fourth resistor is respectively connected to the gate of the first NMOS tube and the gate of the first PMOS tube, the source of the first NMOS tube is grounded, the drain of the first NMOS tube is connected to the drain of the first PMOS tube and the first end of the fifth resistor, the first end of the third resistor and the source of the first PMOS tube are connected to the first power supply, and the second end of the fifth resistor is connected to the detection end of the first SIM card holder.

[0007] In one embodiment, the communication circuit further includes: a signal detection circuit: The signal detection circuit is also connected to the baseband chip via a serial port bus; The signal detection circuit is used to detect the signal strength of the current baseband chip and send it to the baseband chip; The baseband chip is further used to generate the corresponding selection signal based on the comparison result between the signal strength and the preset signal strength; The preset signal strength is the signal strength of the baseband chip corresponding to a preset time before.

[0008] In one embodiment, the communication circuit further includes: a USB interface circuit: The USB interface circuit is connected to the second communication terminal of the baseband chip; The USB interface circuit is used to enable the baseband chip to communicate with the vision module through the USB interface when the vision module is connected.

[0009] In one embodiment, the USB interface circuit includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first inductor, and a second inductor; The second communication end includes a first differential signal line and a second differential signal line, and the USB interface includes a first USB data interface and a second USB data interface; The first end of the first inductor is used to connect the first USB data interface, the first end of the second inductor is used to connect the second USB data interface, the second end of the first inductor is connected to the first differential signal line of the baseband chip, and the second end of the second inductor is connected to the second differential signal line of the baseband chip; the first end of the first inductor is also connected to the first end of the first capacitor, the first end of the second capacitor and the first end of the third capacitor respectively, and the second end of the first inductor is also connected to the second end of the first capacitor; the first end of the second inductor is also connected to the second end of the third capacitor, the first end of the fourth capacitor and the first end of the fifth capacitor respectively, and the second end of the second inductor is also connected to the second end of the fourth capacitor; the second end of the second capacitor and the second end of the fifth capacitor are grounded.

[0010] In one embodiment, the USB interface circuit further includes: a sixth resistor, a seventh resistor, a first TVS tube and a second TVS tube; The second end of the sixth resistor is connected to the second end of the first inductor, the first end of the sixth resistor is respectively connected to the first test interface and the cathode of the first TVS tube, and the anode of the first TVS tube is grounded; the second end of the seventh resistor is connected to the second end of the second inductor, the first end of the seventh resistor is respectively connected to the second test interface and the cathode of the second TVS tube, and the anode of the second TVS tube is grounded.

[0011] In one embodiment, the USB interface circuit further includes: an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a second NMOS transistor and a third NMOS transistor; The USB interface also includes a USB power interface; The first end of the eighth resistor is connected to the first differential signal line of the baseband chip and the source of the second NMOS tube, and the drain of the second NMOS tube is respectively connected to the first end of the ninth resistor and the second end of the first inductor; the second end of the ninth resistor is connected to the USB power interface; the second end of the eighth resistor and the gate of the second NMOS tube are connected to the first power supply; the first end of the tenth resistor is connected to the second differential signal line of the baseband chip and the source of the third NMOS tube, and the drain of the third NMOS tube is respectively connected to the first end of the eleventh resistor and the second end of the second inductor; the second end of the eleventh resistor is connected to the USB power interface; the second end of the eleventh resistor and the gate of the third NMOS tube are connected to the second power supply.

[0012] In one embodiment, the communication circuit further includes: a radio frequency circuit and an antenna matching circuit; The input end of the radio frequency circuit is connected to the radio frequency output end of the baseband chip, the output end of the radio frequency circuit is connected to the antenna matching circuit, and the antenna matching circuit is also connected to the antenna; The baseband chip is further used to convert the image data sent by the visual module into a digital baseband signal when communicating with the SIM card and the visual module, and send the digital baseband signal to the radio frequency circuit; The RF circuit is used to send a corresponding RF signal to the antenna matching circuit when receiving the digital baseband signal, so that the RF signal can be converted into electromagnetic waves through the antenna matching circuit in cooperation with the antenna and then wirelessly transmitted to the base station.

[0013] In one embodiment, the antenna matching circuit includes: a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, and a third inductor; The first end of the sixth capacitor is connected to the output end of the RF circuit, the second end of the sixth capacitor is respectively connected to the first end of the seventh capacitor and the first end of the eighth capacitor, the second end of the seventh capacitor is respectively connected to the first end of the ninth capacitor, the first end of the third inductor and the antenna; the second end of the eighth capacitor, the second end of the ninth capacitor, and the second end of the third inductor are grounded.

[0014] In addition, to achieve the above-mentioned purpose, the present application also provides a communication module that can be applied to smart vision scenes, and the communication module adopts the communication circuit that can be applied to smart vision scenes as described above.

[0015] The present application provides a communication circuit and a communication module that can be applied to smart visual scenarios. The communication circuit includes: a first selection circuit, a second selection circuit and a baseband chip; the first output end of the baseband chip is connected to the control end of the first selection circuit and the control end of the second selection circuit, the first communication end of the baseband chip is connected to the first end of the second selection circuit, the second end of the second selection circuit is connected to the first communication end of the first SIM card holder, the third end of the second selection circuit is connected to the first communication end of the second SIM card holder, the first output end of the first selection circuit is connected to the detection end of the first SIM card holder and the first input end of the baseband chip, and the The second output end is connected to the detection end of the second SIM card holder and the second input end of the baseband chip; the first SIM card holder and the second SIM card holder send actual detection signals to the baseband chip when the SIM card is connected; the first selection circuit is used to send a corresponding analog detection signal to the baseband chip based on the selection signal sent by the baseband chip; the second selection circuit is used to connect the communication channel between the baseband chip and the first SIM card holder or the second SIM card holder based on the selection signal; the baseband chip is used to communicate with the corresponding SIM card through the corresponding communication channel based on the analog detection signal and the actual detection signal.

[0016] In the communication circuit, the baseband chip controls the first selection circuit to generate an analog detection signal by sending a selection signal, and superimposes the analog detection signal with the actual detection signal generated by the SIM card inserted into the corresponding SIM card holder and then feeds it back to the baseband chip, so that the baseband chip confirms whether it needs to communicate with the corresponding SIM card. At the same time, the second selection circuit is also controlled by the selection signal to switch the communication channel between the baseband chip and the corresponding SIM card holder into a conductive state. The baseband chip will establish communication with the corresponding SIM card only when it is connected to the corresponding SIM card. Since the software control logic and the hardware channel are switched synchronously, the SIM card data confusion caused by software control errors in the process of repeatedly switching SIM cards is avoided, thereby improving the stability of system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 A structural diagram of a communication circuit embodiment 1 of the present application that can be applied to a smart visual scene; Figure 2 A circuit connection diagram provided for the second embodiment of the communication circuit applicable to the intelligent visual scene of the present application; Figure 3 Another circuit connection diagram provided for the second embodiment of the communication circuit of the present application that can be applied to smart vision scenarios.

[0020] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0022] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0023] This application proposes a first embodiment of a communication circuit that can be applied to smart visual scenarios. Please refer to Figure 1 , the communication circuit includes: a first selection circuit 10, a second selection circuit 20 and a baseband chip 30; The first output end of the baseband chip 30 is connected to the control end of the first selection circuit 10 and the control end of the second selection circuit 20, the first communication end of the baseband chip 30 is connected to the first end of the second selection circuit 20, the second end of the second selection circuit 20 is connected to the first communication end of the first SIM card socket B1, the third end of the second selection circuit 20 is connected to the first communication end of the second SIM card socket B2, the first output end of the first selection circuit 10 is connected to the detection end of the first SIM card socket B1 and the first input end of the baseband chip 30, the second output end of the first selection circuit 10 is connected to the detection end of the second SIM card socket B2 and the second input end of the baseband chip 30; the first SIM card socket B1 and the second SIM card socket B2 send actual detection signals to the baseband chip 30 when a SIM card is connected; The first selection circuit 10 is used to send a corresponding analog detection signal to the baseband chip 30 based on the selection signal sent by the baseband chip 30; The second selection circuit 20 is used to connect the communication channel between the baseband chip 30 and the first SIM card socket B1 or the second SIM card socket B2 based on the selection signal; The baseband chip 30 is used to communicate with the corresponding SIM card through the corresponding communication channel based on the simulated detection signal and the actual detection signal.

[0024] It should be understood that both the first SIM card holder B1 and the second SIM card holder B2 are used to insert SIM cards (not shown in the figure). In this embodiment, it can be assumed that two different SIM cards are inserted into the first SIM card holder B1 and the second SIM card holder B2 respectively. Among them, the detection end of the first SIM card holder B1 and the detection end of the second SIM card holder B2 are connected to a physical switch (not shown in the figure), and the two ends of the physical switch are respectively connected to the ground wire and the first input end or the second input end of the baseband chip 30. When the SIM card is fully inserted, the physical switch will be pressed to close, so that the detection end is approximately grounded, thereby causing the baseband chip 30 to receive a low-level detection signal, and the baseband chip 30 can establish a communication relationship with the SIM card; when the SIM card is pulled out, the physical switch is disconnected, the detection end is no longer grounded and returns to the default high level (connected to the corresponding power supply by the SIM card holder structure), and the baseband chip 30 will not establish a communication relationship with the SIM card. Among them, a certain impedance is set between the detection end of the first SIM card socket B1 and the detection end of the second SIM card B2 and the SIM card contact part (that is, between the physical switch). Therefore, when one end of the physical switch is grounded, if the other end receives a high-level electrical signal, the baseband chip 30 will also receive a high-level electrical signal.

[0025] It should be noted that, in this embodiment, the selection signal refers to a logic signal generated by the baseband chip 30 for indicating the selection of the SIM card to be communicated. When the first selection circuit 10 receives the selection signal, it will generate a pair of analog detection signals with opposite high and low levels, and send them to the detection end of the first SIM card holder B1 and the detection end of the second SIM card holder B2, respectively, so that the voltages of the detection ends in the first SIM card holder B1 and the second SIM card holder B2 remain high and low, that is, only one SIM card in the two SIM card holders is allowed to communicate. At the same time, the second selection circuit 20 will also receive the same selection signal and select the connection object (the second end or the third end) of the first end of the circuit. When the first end is connected to the second end, the communication channel between the baseband chip 30 and the first SIM card socket B1 is opened, and the communication channel between the baseband chip 30 and the second SIM card socket B2 is closed, and the baseband chip 30 can only receive communication data transmitted from the first SIM card socket B1; when the first end is connected to the third end, the communication channel between the baseband chip 30 and the second SIM card socket B2 is opened, and the communication channel between the baseband chip 30 and the first SIM card socket B1 is closed, and the baseband chip 30 can only receive communication data transmitted from the second SIM card socket B2.

[0026] It is easy to understand that in this embodiment, since the control signals of the first selection circuit 10 and the second selection circuit 20 are both selection signals output by the baseband chip 30, the working logic of the first selection circuit 10 corresponds to the working logic of the second selection circuit 20. In the specific implementation, it can be considered that there are SIM cards in both the first SIM card holder B1 and the second SIM card holder B2 in the initial state, and the two actual detection signals received by the baseband chip 30 in the initial state are both low-level signals. When the baseband chip 30 sends a selection signal to the first selection circuit 10 and the second selection circuit 20, the first selection circuit 10 will send a corresponding analog detection signal to the first SIM card holder B1 and the second SIM card holder B2, so that the actual detection signal sent by one of the SIM card holders is forced to be pulled up from a low level to a high level, and the actual detection signal sent by the other SIM card holder and the received analog detection signal are both low levels, so the superimposed signal received by the baseband chip 30 is actually still a low level, so it can be considered that the SIM card can communicate. At the same time, the second selection circuit 20 will correspondingly switch the communication channel to the channel connected to the above-mentioned SIM card that can communicate. In this way, in software control, the baseband chip 30 can communicate with the SIM card, and in the hardware circuit, the communication channel between the baseband chip 30 and the SIM card is opened separately. No matter how the SIM card is switched, the entire circuit will maintain the above state. Even if an error occurs in the software control, the baseband chip 30 will not be able to receive erroneous communication data, that is, it will not be disturbed, thereby ensuring that the circuit and system operation are more stable.

[0027] The communication circuit proposed above is adapted to a visual module 60 (such as a camera module) capable of remote communication. In some scenarios where the SIM card needs to be switched repeatedly to ensure the communication quality, the SIM card can be switched stably each time, thereby ensuring that the visual module 60 and the remote host can better maintain a communication relationship and send the image of the monitored area to the remote host in real time.

[0028] The present application provides a communication circuit applicable to a smart vision scene, the communication circuit comprising: a first selection circuit, a second selection circuit and a baseband chip; the first output end of the baseband chip is connected to the control end of the first selection circuit and the control end of the second selection circuit, the first communication end of the baseband chip is connected to the first end of the second selection circuit, the second end of the second selection circuit is connected to the first communication end of the first SIM card holder, the third end of the second selection circuit is connected to the first communication end of the second SIM card holder, the first output end of the first selection circuit is connected to the detection end of the first SIM card holder and the first input end of the baseband chip, the second output end of the first selection circuit is connected to the detection end of the second SIM card holder and the second input end of the baseband chip; the first SIM card holder and the second SIM card holder send an actual detection signal to the baseband chip when a SIM card is connected; the first selection circuit is used to send a corresponding analog detection signal to the baseband chip based on the selection signal sent by the baseband chip; the second selection circuit is used to connect the communication channel between the baseband chip and the first SIM card holder or the second SIM card holder based on the selection signal; the baseband chip is used to communicate with the corresponding SIM card through the corresponding communication channel based on the analog detection signal and the actual detection signal. In the communication circuit, the baseband chip controls the first selection circuit to generate an analog detection signal by sending a selection signal, and superimposes the analog detection signal with the actual detection signal generated by the SIM card inserted into the corresponding SIM card holder and then feeds it back to the baseband chip, so that the baseband chip confirms whether it needs to communicate with the corresponding SIM card. At the same time, the second selection circuit is also controlled by the selection signal to switch the communication channel between the baseband chip and the corresponding SIM card holder into a conductive state. The baseband chip will establish communication with the corresponding SIM card only when it is connected to the corresponding SIM card. Since the software control logic and the hardware channel are switched synchronously, the SIM card data confusion caused by software control errors in the process of repeatedly switching SIM cards is avoided, thereby improving the stability of system operation.

[0029] Based on the first embodiment of the communication circuit applicable to the smart visual scene of the present application, in the second embodiment of the communication circuit applicable to the smart visual scene of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 2 , the first selection circuit 10 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first NMOS transistor Qn1, a first PMOS transistor Qp1 and a first N-type transistor Vn1; The first output end of the baseband chip 30 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the base of the first N-type transistor Vn1; the emitter of the first N-type transistor Vn1 and the second end of the second resistor R2 are grounded, the collector of the first N-type transistor Vn1 is respectively connected to the second end of the third resistor R3, the first end of the fourth resistor R4 and the detection end of the second SIM card socket B2, the second end of the fourth resistor R4 is respectively connected to the gate of the first NMOS transistor Qn1 and the gate of the first PMOS transistor Qp1, the source of the first NMOS transistor Qn1 is grounded, the drain of the first NMOS transistor Qn1 is connected to the drain of the first PMOS transistor Qp1 and the first end of the fifth resistor R5, the first end of the third resistor R3 and the source of the first PMOS transistor Qp1 are connected to the first power supply VCC1, and the second end of the fifth resistor R5 is connected to the detection end of the first SIM card socket B1.

[0030] It should be noted that, in this embodiment, the first resistor R1, the second resistor R2, the third resistor R3 and the first N-type transistor Vn1 constitute a driving circuit. When the baseband chip 30 outputs a high-level selection signal, the first N-type transistor Vn1 is turned on, and the collector voltage of the first N-type transistor Vn1 is pulled down, that is, a low-level analog detection signal is output to the detection end of the second SIM card holder B2. The fourth resistor R4, the first NMOS transistor Qn1, the first PMOS transistor Qp1 and the fifth resistor R5 constitute a reverse push-pull circuit. When the collector of the first N-type transistor Vn1 is grounded and the collector voltage is pulled down, the first PMOS transistor Qp1 is turned on, the first NMOS transistor Qn1 is turned off, and a high-level signal is output, that is, a high-level analog detection signal is output to the detection end of the first SIM card holder B1.

[0031] Correspondingly, when the baseband chip 30 outputs a low-level selection signal, the first N-type transistor Vn1 is turned off, and the collector voltage of the first N-type transistor Vn1 is pulled high by the first power supply VCC1, that is, a high-level analog detection signal is output to the detection end of the second SIM card holder B2. At this time, the first PMOS tube Qp1 is turned off, and the first NMOS tube is turned on, and a low-level signal is output, that is, a low-level analog detection signal is output to the detection end of the first SIM card holder B1. Among them, the fourth resistor R4 and the fifth resistor R5 are both current limiting resistors.

[0032] Furthermore, in this embodiment, the communication circuit further includes: a signal detection circuit 40: The signal detection circuit 40 is also connected to the baseband chip 30 via a serial port bus; The signal detection circuit 40 is used to detect the signal strength of the current baseband chip 30 and send it to the baseband chip 30; The baseband chip 30 is further used to generate the corresponding selection signal based on the comparison result between the signal strength and the preset signal strength; The preset signal strength is the signal strength of the baseband chip 30 corresponding to a preset time before.

[0033] It should be noted that, in this embodiment, the communication circuit may also include a signal detection circuit 40. After the baseband chip 30 communicates with any SIM card, a corresponding communication signal will be generated. At this time, the signal acquisition circuit with detection and amplification functions connected to the serial bus can collect the signal strength of the communication signal, and the signal strength can be fed back to the baseband chip 30 in an appropriate manner, such as converting it into a digital signal. After receiving the signal strength, the baseband chip 30 can compare it with the pre-recorded preset signal strength, and determine whether it is necessary to switch the SIM card at present according to the comparison result. If the current signal strength cannot reach the preset signal strength, a corresponding selection signal can be generated to switch the SIM card and re-establish the communication relationship, so as to enjoy the communication service provided by another SIM card.

[0034] It is easy to understand that the preset signal strength refers to the signal strength of the communication signal generated by the baseband chip 30 recorded before the preset time. The preset time can be the time recorded when the SIM card was last switched, or can be an arbitrarily set period of time.

[0035] Furthermore, in this embodiment, the communication circuit further includes: a USB interface circuit 50: The USB interface circuit 50 is connected to the second communication terminal of the baseband chip 30; The USB interface circuit 50 is used to enable the baseband chip 30 to communicate with the vision module 60 through the USB interface when the vision module 60 is connected.

[0036] It should be noted that, in the present embodiment, a USB interface circuit 50 can be used to establish a connection relationship between the USB communication line of the baseband chip 30 and an external interface, for example, to connect to the visual module 60. The visual module 60 can be a camera or a device, apparatus or equipment for generating image data, etc., for monitoring the target area and generating corresponding images or videos, which can be stored and called in the form of image data. When the baseband chip 30 is connected to the visual module 60, a communication relationship can be established with the USB communication protocol, so as to perform two-way communication. The baseband chip 30 can receive the image data transmitted by the visual module 60 through the USB bus, and after modulating, encrypting and other processing methods, generate a corresponding communication signal, and transmit it wirelessly to the base station 90 through other circuits.

[0037] As a preferred method, the baseband chip 30 can be a PANGU M900 chip, which has an 8-core 64-bit high-performance CPU (2.3GHz). A single chip integrates the CPU, graphics card, sound card, network card, etc., can quickly calculate and process image signals and data, has strong computing power, can build a variety of functional circuits, and facilitates circuit updates and iterations.

[0038] Further, in this embodiment, the USB interface circuit 50 includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a first inductor L1 and a second inductor L2; The second communication end includes a first differential signal line and a second differential signal line, and the USB interface includes a first USB data interface and a second USB data interface; The first end of the first inductor L1 is used to connect the first USB data interface, the first end of the second inductor L2 is used to connect the second USB data interface, the second end of the first inductor L1 is connected to the first differential signal line of the baseband chip 30, and the second end of the second inductor L2 is connected to the second differential signal line of the baseband chip 30; the first end of the first inductor L1 is also connected to the first end of the first capacitor C1, the first end of the second capacitor C2 and the first end of the third capacitor C3, and the second end of the first inductor L1 is also connected to the second end of the first capacitor C1; the first end of the second inductor L2 is also connected to the second end of the third capacitor C3, the first end of the fourth capacitor C4 and the first end of the fifth capacitor C5, and the second end of the second inductor L2 is also connected to the second end of the fourth capacitor C4; the second end of the second capacitor C2 and the second end of the fifth capacitor C5 are grounded.

[0039] It should be noted that the visual module 60 is connected to the baseband chip 30 via the USB data line of the USB interface. The USB data line is a pair of transmission lines for transmitting differential signals. In the present embodiment, the third capacitor C3 is an X capacitor, which is mainly used to absorb high-frequency interference and reduce power supply noise. The second capacitor C2 and the fifth capacitor C5 are Y capacitors, which are mainly used to suppress common-mode interference and eliminate high-frequency noise generated by external incoming circuits or internal circuits. The first inductor L1 and the second inductor L2 are a pair of common-mode inductors, which are used to increase the impedance of the common-mode loop and suppress common-mode noise and high-frequency interference in the circuit. The first capacitor C1 and the fourth capacitor C4 are respectively connected in parallel with the first inductor L1 and the second inductor L2, which can form a low-pass filter, so that only low-frequency image signals can be transmitted in the line, which helps to reduce signal distortion and attenuation, improve the quality of signal transmission, and further enhance the communication stability of the entire system.

[0040] Furthermore, in this embodiment, the USB interface circuit 50 further includes: a sixth resistor R6, a seventh resistor R7, a first TVS tube D1 and a second TVS tube D2; The second end of the sixth resistor R6 is connected to the second end of the first inductor L1, the first end of the sixth resistor R6 is respectively connected to the first test interface Pc1 and the cathode of the first TVS tube D1, and the anode of the first TVS tube D1 is grounded; the second end of the seventh resistor R7 is connected to the second end of the second inductor L2, the first end of the seventh resistor R7 is respectively connected to the second test interface Pc2 and the cathode of the second TVS tube D2, and the anode of the second TVS tube D2 is grounded.

[0041] It should be noted that, in this embodiment, the USB interface circuit 50 may also be provided with a first test interface Pc1 and a second test interface Pc2 for external connection. When the USB communication needs to be tested, the first test interface Pc1 and the second test interface Pc2 will transmit corresponding differential signals for testing the USB communication (signal integrity) separately.

[0042] It is easy to understand that in this embodiment, the sixth resistor R6 constitutes the current limiting resistor of the first test interface Pc1, and the seventh resistor R7 constitutes the current limiting resistor of the second test interface Pc2. The first TVS tube D1 is used to protect the first test interface Pc1 to prevent excessive peak current from damaging the circuit when the first test interface Pc1 is connected or disconnected. The corresponding second TVS tube D2 has a similar function to the first TVS tube D1 and is used to protect the second test interface Pc2.

[0043] It is worth noting that when the first test interface Pc1 and the second test interface Pc2 are not in use, the first TVS tube D1 and the second TVS tube D2 can also protect the two differential signal lines of the USB interface to prevent abnormal voltage or current from occurring during USB communication. This arrangement can more quickly troubleshoot the image transmission communication process and facilitate the search and repair of communication faults.

[0044] Furthermore, in this embodiment, the USB interface circuit 50 further includes: an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a second NMOS transistor Qn2, and a third NMOS transistor Qn3; The USB interface also includes a USB power interface Pu0; The first end of the eighth resistor R8 is connected to the first differential signal line of the baseband chip 30 and the source of the second NMOS transistor Qn2, and the drain of the second NMOS transistor Qn2 is respectively connected to the first end of the ninth resistor R9 and the second end of the first inductor L1; the second end of the ninth resistor R9 is connected to the USB power interface Pu0; the second end of the eighth resistor R8 and the gate of the second NMOS transistor Qn2 are connected to the first power supply VCC1; the first end of the tenth resistor R10 is connected to the second differential signal line of the baseband chip 30 and the source of the third NMOS transistor Qn3, and the drain of the third NMOS transistor Qn3 is respectively connected to the first end of the eleventh resistor R11 and the second end of the second inductor L2; the second end of the eleventh resistor R11 is connected to the USB power interface Pu0; the second end of the eleventh resistor R11 and the gate of the third NMOS transistor Qn3 are connected to the second power supply VCC2.

[0045] It should be noted that the USB power interface Pu0 refers to the interface connected to the power line of the visual module 60. In actual situations, due to the existence of multiple voltages for USB communication, the system voltage inside the visual module 60 and the system voltage of the communication circuit may not be inconsistent. In this embodiment, the second power supply VCC2 is the system power supply of the baseband chip 30; in order to meet the requirement of the serial port baud rate reaching 921600bps, a set of level conversion circuits can be formed by the eighth resistor R8, the ninth resistor R9 and the second NMOS tube Qn2, and a set of level conversion circuits can be formed by the tenth resistor R10, the eleventh resistor R11 and the third NMOS tube Qn3, so that the baseband chip 30 can successfully identify the voltage of the image signal transmitted by the USB communication line.

[0046] Furthermore, in this embodiment, the communication circuit further includes: a radio frequency circuit 70 and an antenna matching circuit 80; The input end of the RF circuit 70 is connected to the RF output end of the baseband chip 30, and the output end of the RF circuit 70 is connected to the antenna matching circuit 80, and the antenna matching circuit 80 is also connected to the antenna ANT; The baseband chip 30 is also used to convert the image data sent by the visual module 60 into a digital baseband signal when communicating with the SIM card and the visual module 60, and send the digital baseband signal to the radio frequency circuit 70; The RF circuit 70 is used to send a corresponding RF signal to the antenna matching circuit 80 when receiving the digital baseband signal, so that the RF signal is converted into an electromagnetic wave through the antenna matching circuit 80 and the antenna ANT and then wirelessly transmitted to the base station 90.

[0047] It should be noted that, in this embodiment, after the baseband chip 30 establishes communication with the SIM card, it can read the user information stored in the SIM card and other data provided by the operator (such as the access point name, address, etc.). During the network access process, it can also generate and transmit authentication data through an encryption algorithm, and transmit it in the communication signal described above, or it can be understood as transmitting it in the form of a digital baseband signal. After generating the digital baseband signal, the baseband chip 30 can transmit it to the radio frequency circuit 70. The radio frequency circuit 70 performs signal modulation and power amplification based on the received digital baseband signal and transmits it to the antenna matching circuit 80. The antenna matching circuit 80 performs impedance matching between the radio frequency circuit 70 and the antenna ANT, so that the antenna ANT can convert the impedance-matched radio frequency signal into an electromagnetic wave and then transmit it outward. The base station 90 can absorb the converted electromagnetic wave and forward it to other surrounding communication devices or communication equipment (not shown in the figure). In addition, the antenna ANT can also receive electromagnetic waves sent by the base station 90, convert them into radio frequency signals, and transmit the radio frequency signals to the radio frequency circuit 70. After the radio frequency circuit 70 performs filtering, frequency conversion, amplification, demodulation and other processing, the corresponding digital signals are obtained, and then the digital signals are transmitted to the baseband chip 30. Among them, impedance matching can reduce signal reflection and loss, and improve the transmission efficiency and performance of the system.

[0048] Through the above two working modes, the baseband chip 30 can communicate wirelessly with an external communication device or communication equipment, and the baseband chip 30 can communicate with the visual module 60 via a USB bus, so that the image data of the visual module 60 can be transmitted to the communication device or communication equipment, so that the communication device or communication equipment can quickly obtain the image data stored in the visual module 60 and convert it into an image or video, which is convenient for the staff to observe the specific events that occurred in the target area within the corresponding time period. In addition, the visual module 60 can also obtain the control instructions sent by the communication device or communication equipment in the above manner, so as to change the monitoring mode, such as changing the monitoring angle, or switching to infrared monitoring and other functions.

[0049] Furthermore, in this embodiment, the antenna matching circuit 80 is also used to convert the RF signal sent by the RF circuit 70 into electromagnetic waves in cooperation with the antenna ANT and then wirelessly transmit it to the target communication module 91 within a preset range.

[0050] It should be noted that the preset range refers to a range in which one end can ensure relatively good communication quality between communication modules, which can be within 100m. In this embodiment, the antenna ANT can also convert the RF signal adapted by the impedance matching circuit 80 into a corresponding electromagnetic wave, and send it to the target communication module 91 within the preset range, or receive the electromagnetic wave sent by the target communication module 91 within the preset range, thereby realizing wireless communication with the target communication module 91.

[0051] It is easy to understand that in this embodiment, the target communication module 91 can be regarded as a small transfer station. When the communication quality between the current antenna ANT and the base station 90 is poor or it is impossible to directly communicate wirelessly with the base station 90, the surrounding target communication modules 91 can be used as transfer stations to first communicate wirelessly with the target communication module 91, and then communicate wirelessly with the base station 90 through the target communication module 91, thereby indirectly realizing wireless communication between the current antenna ANT and the base station 90. In this way, even if the signal in the area where the current communication module is located is poor, wireless communication with a distant communication device or communication equipment can be indirectly realized through wireless communication between modules.

[0052] As a special case, see Figure 3If there are multiple target communication modules 91 around, and the target communication modules 91 within the preset range cannot directly communicate with the base station 90, one of the other target communication modules 91 within the preset range of each target communication module 91 can be used as the next transfer station until the last target communication module 91 successfully establishes a wireless communication relationship with the base station 90. The longer communication line formed by the above target communication modules 91 can also enable relatively stable wireless communication between the antenna ANT and the base station 90.

[0053] Further, in this embodiment, the antenna matching circuit 80 includes: a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, and a third inductor L3; The first end of the sixth capacitor C6 is connected to the output end of the RF circuit 70, the second end of the sixth capacitor C6 is respectively connected to the first end of the seventh capacitor C7 and the first end of the eighth capacitor C8, the second end of the seventh capacitor C7 is respectively connected to the first end of the ninth capacitor C9, the first end of the third inductor L3 and the antenna ANT; the second end of the eighth capacitor C8, the second end of the ninth capacitor C9, and the second end of the third inductor L3 are grounded.

[0054] It should be noted that, in this embodiment, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9 and the third inductor L3 form a π-type antenna matching circuit 80, and its wiring impedance is maintained at 50Ω. The antenna ANT frequency can be 703~5000MHZ.

[0055] It is worth noting that, in actual situations, the antenna matching circuit 80 may also be a double L-shape, and there may be two antenna matching circuits 80 , and the structures of the two antenna matching circuits 80 remain the same and will not be described in detail.

[0056] The embodiment of the present application also provides a communication module that can be applied to smart vision scenes, and the communication module adopts the communication circuit that can be applied to smart vision scenes as described above. The communication module provided in the embodiment of the present application adopts the communication circuit that can be applied to smart vision scenes as described above, which can solve the technical problem of how to make the baseband chip communicate more stably with one of the SIM cards in dual-card single-standby mode. Compared with the prior art, the beneficial effects of the communication module provided in the embodiment of the present application are the same as the beneficial effects of the communication circuit that can be applied to smart vision scenes provided in the above-mentioned embodiment, which will not be repeated here.

[0057] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent processing scope of the present application.

Claims

1. A communication circuit applicable to intelligent visual scenes, characterized in that: The communication circuit comprises: a first selection circuit, a second selection circuit and a baseband chip; The first output end of the baseband chip is connected to the control end of the first selection circuit and the control end of the second selection circuit, the first communication end of the baseband chip is connected to the first end of the second selection circuit, the second end of the second selection circuit is connected to the first communication end of the first SIM card holder, the third end of the second selection circuit is connected to the first communication end of the second SIM card holder, the first output end of the first selection circuit is connected to the detection end of the first SIM card holder and the first input end of the baseband chip, and the second output end of the first selection circuit is connected to the detection end of the second SIM card holder and the second input end of the baseband chip; the first SIM card holder and the second SIM card holder send actual detection signals to the baseband chip when the SIM card is connected; The first selection circuit is used to send a corresponding analog detection signal to the baseband chip based on a selection signal sent by the baseband chip; The second selection circuit is used to connect the communication channel between the baseband chip and the first SIM card holder or the second SIM card holder based on the selection signal; The baseband chip is used to communicate with the corresponding SIM card through the corresponding communication channel based on the simulated detection signal and the actual detection signal.

2. The communication circuit applicable to intelligent visual scenes as claimed in claim 1, characterized in that: The first selection circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first NMOS transistor, a first PMOS transistor and a first N-type triode; The first output end of the baseband chip is connected to the first end of the first resistor, and the second end of the first resistor is respectively connected to the first end of the second resistor and the base of the first N-type transistor; the emitter of the first N-type transistor and the second end of the second resistor are grounded, the collector of the first N-type transistor is respectively connected to the second end of the third resistor, the first end of the fourth resistor and the detection end of the second SIM card holder, the second end of the fourth resistor is respectively connected to the gate of the first NMOS tube and the gate of the first PMOS tube, the source of the first NMOS tube is grounded, the drain of the first NMOS tube is connected to the drain of the first PMOS tube and the first end of the fifth resistor, the first end of the third resistor and the source of the first PMOS tube are connected to the first power supply, and the second end of the fifth resistor is connected to the detection end of the first SIM card holder.

3. The communication circuit applicable to intelligent visual scenes as claimed in claim 1, characterized in that: The communication circuit also includes: a signal detection circuit: The signal detection circuit is also connected to the baseband chip via a serial port bus; The signal detection circuit is used to detect the signal strength of the current baseband chip and send it to the baseband chip; The baseband chip is further used to generate the corresponding selection signal based on the comparison result between the signal strength and the preset signal strength; The preset signal strength is the signal strength of the baseband chip corresponding to a preset time before.

4. The communication circuit applicable to intelligent visual scenes as claimed in claim 1, characterized in that: The communication circuit also includes: USB interface circuit: The USB interface circuit is connected to the second communication terminal of the baseband chip; The USB interface circuit is used to enable the baseband chip to communicate with the vision module through the USB interface when the vision module is connected.

5. The communication circuit applicable to intelligent visual scenes as claimed in claim 4, characterized in that: The USB interface circuit comprises: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first inductor and a second inductor; The second communication end includes a first differential signal line and a second differential signal line, and the USB interface includes a first USB data interface and a second USB data interface; The first end of the first inductor is used to connect the first USB data interface, the first end of the second inductor is used to connect the second USB data interface, the second end of the first inductor is connected to the first differential signal line of the baseband chip, and the second end of the second inductor is connected to the second differential signal line of the baseband chip; the first end of the first inductor is also connected to the first end of the first capacitor, the first end of the second capacitor and the first end of the third capacitor respectively, and the second end of the first inductor is also connected to the second end of the first capacitor; the first end of the second inductor is also connected to the second end of the third capacitor, the first end of the fourth capacitor and the first end of the fifth capacitor respectively, and the second end of the second inductor is also connected to the second end of the fourth capacitor; the second end of the second capacitor and the second end of the fifth capacitor are grounded.

6. The communication circuit applicable to intelligent visual scenes as claimed in claim 5, characterized in that: The USB interface circuit further includes: a sixth resistor, a seventh resistor, a first TVS tube and a second TVS tube; The second end of the sixth resistor is connected to the second end of the first inductor, the first end of the sixth resistor is respectively connected to the first test interface and the cathode of the first TVS tube, and the anode of the first TVS tube is grounded; the second end of the seventh resistor is connected to the second end of the second inductor, the first end of the seventh resistor is respectively connected to the second test interface and the cathode of the second TVS tube, and the anode of the second TVS tube is grounded.

7. The communication circuit applicable to intelligent visual scenes as claimed in claim 5, characterized in that: The USB interface circuit further includes: an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a second NMOS transistor and a third NMOS transistor; The USB interface also includes a USB power interface; The first end of the eighth resistor is connected to the first differential signal line of the baseband chip and the source of the second NMOS tube, and the drain of the second NMOS tube is respectively connected to the first end of the ninth resistor and the second end of the first inductor; the second end of the ninth resistor is connected to the USB power interface; the second end of the eighth resistor and the gate of the second NMOS tube are connected to the first power supply; the first end of the tenth resistor is connected to the second differential signal line of the baseband chip and the source of the third NMOS tube, and the drain of the third NMOS tube is respectively connected to the first end of the eleventh resistor and the second end of the second inductor; the second end of the eleventh resistor is connected to the USB power interface; the second end of the eleventh resistor and the gate of the third NMOS tube are connected to the second power supply.

8. The communication circuit applicable to intelligent visual scenes as claimed in claim 4, characterized in that: The communication circuit also includes: a radio frequency circuit and an antenna matching circuit; The input end of the radio frequency circuit is connected to the radio frequency output end of the baseband chip, the output end of the radio frequency circuit is connected to the antenna matching circuit, and the antenna matching circuit is also connected to the antenna; The baseband chip is further used to convert the image data sent by the visual module into a digital baseband signal when communicating with the SIM card and the visual module, and send the digital baseband signal to the radio frequency circuit; The RF circuit is used to send a corresponding RF signal to the antenna matching circuit when receiving the digital baseband signal, so that the RF signal can be converted into electromagnetic waves through the antenna matching circuit in cooperation with the antenna and then wirelessly transmitted to the base station.

9. The communication circuit applicable to intelligent visual scenes as claimed in claim 8, characterized in that: The antenna matching circuit includes: a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, and a third inductor; The first end of the sixth capacitor is connected to the output end of the RF circuit, the second end of the sixth capacitor is respectively connected to the first end of the seventh capacitor and the first end of the eighth capacitor, the second end of the seventh capacitor is respectively connected to the first end of the ninth capacitor, the first end of the third inductor and the antenna; the second end of the eighth capacitor, the second end of the ninth capacitor, and the second end of the third inductor are grounded.

10. A communication module applicable to intelligent visual scenes, characterized in that: The communication module adopts a communication circuit applicable to smart vision scenarios as described in any one of claims 1-9.

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