Iot intercom host adapter board circuit

Abstract

The utility model discloses an intercom host adapter plate circuit of internet of things, include: core control chip U2, adopt ML160 chip, be used for realizing the core control and communication function of equipment, host docking interface circuit is linked with core control chip U2, be used for with host mainboard transmission audio signal and serial communication, and power connection, mobile phone card circuit is linked with core control chip U2, be used for providing power, clock, reset and the condition of data transmission for USIM card, realizes the data interaction with external equipment. Core control chip U2 adopts ML160 chip, integrates 3G, 4G network communication function, breaks through the limitation that traditional intercom system only supports 2G network. Effectively solved the problem that equipment can not be used because of 2G base station is closed, expands network coverage, ensures that can stable communication under different scenes, adapts to the network upgrading demand of all places.

Description

Technical Field

[0001] This utility model relates to the field of intercom host technology, specifically to the Internet of Things intercom host adapter board circuit. Background Technology

[0002] As a core vertical transportation tool in high-rise buildings, the safe operation and emergency communication capabilities of elevators are directly related to passenger safety. Elevator intercom systems are crucial equipment for ensuring emergency communication. In emergencies such as elevator entrapment or malfunctions, passengers can establish real-time communication with the monitoring center, property management office, or rescue personnel through the intercom device inside the car. Therefore, stable, clear, and timely intercom functionality is a mandatory requirement of elevator safety standards. With the development of elevator technology and the increasing complexity of application scenarios, intercom systems have gradually revealed a series of technical shortcomings.

[0003] 1. System compatibility issues are prominent. Early elevator intercom systems primarily used analog signals, while in recent years, digital intercom systems, such as those using IP and bus protocols, have become mainstream due to their strong anti-interference capabilities and rich functionality. However, in practical applications, both old and new systems coexist. When upgrading older elevators, some analog equipment is retained, and different brands of equipment use different protocols. For example, the intercom host, car intercom units, and monitoring center platform may come from different manufacturers, resulting in inability for the devices to communicate directly. This necessitates frequent replacements of the entire system, leading to extremely high costs.

[0004] 2. The signal type does not match the transmission requirements. Analog signals are easily affected by electromagnetic interference during elevator operation, resulting in noise and disconnection during calls. Although digital signals are more resistant to interference, they require specific protocol support and cannot be directly connected to analog equipment.

[0005] 3. Regulatory requirements are becoming increasingly stringent. Elevator safety regulations in various countries clearly require intercom systems to have functions such as two-way communication, priority for emergency calls, and real-time connection with the monitoring center. Some regions also require integration with fire protection systems and public security emergency platforms, which places higher demands on the system's protocol compatibility and scalability, making it difficult for traditional single-function intercom devices to meet these requirements.

[0006] To address this, an IoT intercom host adapter board circuit is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide an IoT intercom host adapter board circuit to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: an IoT intercom host adapter board circuit, comprising:

[0009] The core control chip U2 uses the ML160 chip to realize the core control and communication functions of the device;

[0010] The host interface circuit is connected to the core control chip U2 and is used to transmit audio signals and serial communication with the host motherboard, as well as for power connection.

[0011] The SIM card circuit, connected to the core control chip U2, provides power, clock, reset, and data transmission conditions for the USIM card, enabling data interaction with external devices.

[0012] The software programming circuit is connected to the core control chip U2 and is used to realize USB data transmission and power supply between devices;

[0013] The voltage regulator circuit, connected to the core control chip U2, is used to step down the 12V input voltage to the 3.8V output.

[0014] Preferably, the core control chip U2 has a capacitor C32 and a resistor R13 connected to pin 46, and a capacitor C33, a bidirectional diode D10 and an antenna ANT connected to the resistor R13.

[0015] Preferably, the host interface circuit includes connector J1;

[0016] Pin 1 of connector J1 is connected to diode D1, and pins 3 and 4 of connector J1 are connected to pins 33 and 34 of core control chip U2.

[0017] The connector J1 has a 6-pin connector connected to one end of a capacitor C4. The other end of the capacitor C4 is connected to capacitors C11 and C12 and a resistor R4. The resistor R4 is connected to pin 24 of the core control chip U2.

[0018] The connector J1 has one end of capacitor C3 connected to pin 7. The other end of capacitor C3 is connected to capacitors C9 and C10 and resistor R3. Resistor R3 is connected to pin 23 of the core control chip U2.

[0019] The connector J1 has its 8th pin connected to one end of capacitor C2, and the other end of capacitor C2 is connected to capacitors C7 and C8 and resistor R2. Resistor R2 is connected to pin 22 of the core control chip U2.

[0020] The connector J1 has a capacitor C1 connected to one end of its 9th pin. The other end of the capacitor C1 is connected to capacitors C5 and C6 and resistor R1. Resistor R1 is connected to pin 21 of the core control chip U2.

[0021] Preferably, the SIM card circuit includes a SIM card slot (SIM1).

[0022] Pin 1 of the SIM1 slot is connected to a bidirectional diode D5, a capacitor C16 and a resistor R8, and the resistor R8 is connected to pin 6 of the core control chip U2.

[0023] Pin 2 of the SIM1 card slot is connected to a bidirectional diode D4, a capacitor C15 and a resistor R7, and the resistor R7 is connected to pin 5 of the core control chip U2.

[0024] The SIM1 card slot has a bidirectional diode D3, a capacitor C14 and a resistor R6 connected to pin 4. The resistor R6 is connected to pin 7 of the core control chip U2.

[0025] Pin 6 of the card slot SIM1 is connected to a bidirectional diode D2, capacitor C13, and resistor R5, and is connected to pin 8 of the core control chip U2. The other end of the resistor R5 is connected to pin 1 of the card slot SIM1.

[0026] Preferably, the software programming circuit includes a Type-C interface connector J3;

[0027] Pins A4 and A9 of the Type-C interface connector J3 are connected, and pin A9 of the Type-C interface connector J3 is connected to diode D8 and capacitor C17.

[0028] The Type-C interface connector J3 has a resistor R9 connected to pin A5.

[0029] The Type-C interface connector J3 has a diode D6 connected to pin A6, which is also connected to pin 26 of the core control chip U2.

[0030] The Type-C interface connector J3 has a diode D7 connected to pin A7, which is connected to pin 27 of the core control chip U2.

[0031] Preferably, pins B9 and B4 of the Type-C interface connector J3 are connected and connected to pin 28 of the core control chip U2;

[0032] Pins B7 and B6 of the Type-C interface connector J3 are connected to pins 27 and 26 of the core control chip U2, respectively.

[0033] The B5 pin of the Type-C interface connector J3 is connected to a resistor R10.

[0034] Preferably, the voltage regulator circuit includes a DC-DC converter chip U1;

[0035] A capacitor C21 is connected between pins 2 and 6 of the chip U1;

[0036] Pin 2 of the chip U1 is also connected to one end of an inductor L1, and the other end of the inductor L1 is connected to capacitors C25, C24, C23, resistor R16, and resistor R17.

[0037] The chip U1 has capacitors C20, C19 and C18 connected to pin 3.

[0038] Pin 5 of the chip U1 is connected to resistors R14 and R15.

[0039] Compared with the prior art, the beneficial effects of this utility model are:

[0040] 1. The core control chip U2 uses the ML160 chip, which integrates 3G and 4G network communication functions, breaking through the limitation of traditional intercom systems that only support 2G networks. This effectively solves the problem of equipment unusability due to the shutdown of 2G base stations, expands network coverage, ensures stable communication in different scenarios, and adapts to the network upgrade needs of various regions.

[0041] 2. The host interface circuit uses connectors to achieve audio signal, serial communication, and power connection with the host motherboard, making it compatible with both analog and digital signal systems. Interoperability between new and old devices, and devices from different brands, can be achieved without replacing the entire system, solving the pain point of inconsistent protocols and significantly reducing the upgrade cost of older elevator intercom systems.

[0042] 3. The audio signal transmission adopts a differential circuit, and with the help of filter capacitors, high-frequency noise is filtered out, reducing the impact of electromagnetic interference during elevator operation on the call, reducing noise and the probability of disconnection. At the same time, through the digital signal processing capabilities of the core chip, anti-interference and compatibility with analog equipment are taken into account, solving the transmission problem caused by signal type mismatch.

[0043] 4. Through 4G network and mobile phone card circuit, it can realize real-time connection with monitoring center, property duty room, fire protection system, public security emergency platform, etc., and supports two-way calling, emergency call priority and other functions. It complies with the mandatory requirements of elevator safety regulations in various countries for emergency communication, has strong scalability and adapts to diverse regulatory scenarios. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the core control chip of this utility model;

[0045] Figure 2 This is a schematic diagram of the host interface circuit of this utility model;

[0046] Figure 3 This is a schematic diagram of the mobile phone card circuit of this utility model;

[0047] Figure 4 This is a schematic diagram of the software programming circuit of this utility model;

[0048] Figure 5 This is a schematic diagram of the voltage regulator circuit of this utility model. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0050] Please see Figure 1-5 This utility model provides a technical solution:

[0051] I. Core control chip: Embedded system circuit based on ML160 chip.

[0052] Core chip: U2 uses the ML160, which is a multi-functional main control / communication chip.

[0053] RF / Antenna: The ANT and matching circuits R13, C32, C33 and D2 are responsible for wireless signal transmission and reception, realizing the communication function.

[0054] Power supply and reset: VBAT power supply, combined with reset, enable and other pins, controls the chip to power on and restart.

[0055] Peripheral interfaces: including GPIO, serial port, and USB, which can be connected to external sensors, communication modules, storage devices, etc.

[0056] LED indicators: LED1, LED2 and transistor driver circuit are used for status display, such as working, communication, and abnormal status.

[0057] II. Host Interface Circuit: This circuit connects to the host motherboard for audio signals, serial communication, and power supply. The following is a description of its working principle and the function of each component:

[0058] 1. Interface and connection parts

[0059] J1: Serves as the interface for external connections, enabling signal and power transmission between external devices and this circuit. The pin definitions clearly define the different functional lines, such as audio input / output (MIC, SPK), serial communication (TXD, RXD), and power supply (VCC, 12V, GND).

[0060] D1: This is a rectifier diode, which prevents reverse power connection. When an external +12V power supply is connected, it ensures unidirectional current flow to power the circuit. If the power supply polarity is reversed, the diode will cut off, protecting subsequent circuits from reverse voltage damage.

[0061] +12V and GND: Provide the DC power required for the circuit to operate. GND is the common ground reference point for the circuit.

[0062] 2. Audio signal path (MIC microphone input, SPK speaker output)

[0063] Capacitors C1 to C4, with a capacitance of 1µF, are electrolytic or monolithic capacitors; C5 to C12, 33pF and 10pF, are small-capacity ceramic capacitors.

[0064] C1 to C4 are audio coupling capacitors, whose function is to block DC and pass AC. For the MIC input and SPK output signals, they block the DC component in the circuit, allowing only the audio AC signal to pass through, thus preventing DC from affecting the operation of the audio equipment, and at the same time achieving signal coupling transmission.

[0065] C5-C12: These are filter capacitors used to filter audio signals and remove high-frequency noise. 33pF and 10pF capacitors can filter out high-frequency interference in different frequency bands, resulting in a purer audio signal and ensuring audio quality.

[0066] Resistors R1 to R4: 0-ohm resistors mainly function as conductors here, used for connecting audio signal paths. They can also be used for debugging and jumper wiring during PCB routing. They also have certain current limiting and impedance matching auxiliary functions, facilitating flexible handling during circuit debugging and production.

[0067] Signal definitions: SW MIC N / P, SW SPK P / N, etc.: SW MIC N / P is the microphone differential input signal, and SW SPKP / N, etc. are the speaker differential output signals. Differential signal transmission can enhance anti-interference capability, improve audio signal transmission quality, and reduce the impact of external noise on audio.

[0068] 3. Serial communication path (TXD1, RXD1 and SW TXD, SW RXD)

[0069] This section is the serial communication line. TXD1 and RXD1 connect to the serial port of external devices via the J1 interface to achieve data transmission and reception. SW TXD and SW RXD are the converted serial port signals, which can be used to communicate with other serial port devices to transmit control commands, data, and other information. They are physically independent of the audio section and can work simultaneously without interfering with each other.

[0070] III. SIM Card Circuit: This is the USIM card interface circuit, used to provide the USIM card with the necessary conditions such as power, clock, reset, and data transmission, enabling data interaction with external devices, such as baseband chips and communication modules. The following explains its working principle and the function of each component:

[0071] 1. Core Interface: USIM Card Slot SIM1

[0072] As the physical connection carrier of the USIM card, it provides pins such as VCC, GND, RST, CLK, and I / O, enabling the USIM card to establish an electrical connection with external circuits and transmit various signals.

[0073] 2. Power supply and filtering section

[0074] SW USIM VDD: Power input line for the USIM card, providing power to the USIM card and ensuring the normal operation of the internal circuitry.

[0075] C13: Filter capacitor. Its function is to filter out high-frequency noise on the power line, making the power input to the USIM card cleaner and more stable, and avoiding voltage fluctuations from interfering with the normal operation of the card.

[0076] R5: Pull-up resistor. When the power path of the USIM card requires a stable level, it is pulled up to SW USIM VDD to ensure that the voltage at the VCC terminal is stable within a reasonable range. It can also limit the current to a certain extent and protect the circuit.

[0077] 3. Signal control and transmission section

[0078] R6, R7, and R8 are all current-limiting and matching resistors.

[0079] Current limiting: Limits the current on the SW USIM RST, SW USIM CLK, and SW USIM DATA lines to prevent excessive current from damaging the USIM card or interface.

[0080] Impedance matching: Makes the impedance of the signal transmission line more compatible with the USIM card and back-end circuitry, reduces signal reflection, improves signal transmission quality, and ensures accurate interaction of reset, clock, and data signals.

[0081] SW USIM RST: Reset signal, used to initialize the USIM card, put the card into the initial working state, and control the card's reset and wake-up process.

[0082] SW USIM CLK: Clock signal, providing a clock reference for USIM card communication. The internal circuitry of the card uses this clock cycle to transmit, receive, and process data, ensuring synchronized communication timing.

[0083] SW USIM DATA: Data signal, enabling bidirectional data transmission between the USIM card and external devices, including authentication information, communication data, etc.

[0084] 4. Protection and Filtering Auxiliary Section

[0085] D2~D5: Transient voltage suppression diodes. When a surge voltage occurs in the circuit, the diodes will quickly conduct, clamping the excessive voltage within a safe range and protecting the USIM card and back-end circuitry from high voltage damage.

[0086] C14 through C16 are all filter capacitors. The 33pF small-capacity capacitors mainly filter out high-frequency noise, further purifying the signal and reducing interference for high-frequency signal lines such as clock and data signals.

[0087] IV. Software Programming Circuit: This is the USB Type-C interface circuit, used to realize USB data transfer and power supply between devices, and to adapt to the Type-C interface specification. The following is an analysis of the core principles and component functions:

[0088] 1. Overall working principle

[0089] The circuit is built around the Type-C interface J3 and implements three core functions:

[0090] Power transmission: The SW VBUS introduces the power supply voltage, which is then transmitted to the connected devices via the VBUS pins A4 / A9, B5 / B9, etc. of the Type-C interface. C17 filters out high-frequency noise on the VBUS line to ensure stable power supply.

[0091] Data communication: SW USB DP / SW USB DM are USB differential data signals, which enable high-speed data transmission between devices through the DP and DM pins A6 / A7, B6 / B7 of the Type-C interface; the CC1 and CC2 pins A5 and B4 are used for protocol negotiation of the Type-C interface.

[0092] Protection and Matching: TVS diodes suppress static electricity and surge voltage, protecting the interface and back-end circuitry; R9 and R10 are pull-up and pull-down resistors, participating in USB device identification and signal matching to make data communication more stable.

[0093] 2. Functions of key components D6~D8

[0094] Function: Transient voltage suppression. When the circuit encounters abnormal high voltage such as electrostatic discharge or power surge, the TVS diode will quickly conduct, clamping the excessive voltage within a safe range and preventing high voltage from damaging the Type-C interface and downstream circuitry.

[0095] V. The voltage regulator circuit is a power conversion circuit based on the DC-DC converter chip H9118. The following describes the working principle of this circuit in stepping down 12V to VBAT 3.8V, and the function of each component:

[0096] 1. Overall Working Principle: This circuit utilizes the internal switching transistor of the H9118 chip for high-frequency switching. Through the energy storage and dissipation characteristics of the inductor and the filtering effect of the capacitor, combined with a feedback control mechanism, it stably steps down the 12V input voltage to a 3.8V output. The H9118 chip adjusts the on and off times of the internal switching transistor based on the voltage signal from the feedback pin, thereby regulating the output voltage.

[0097] 2. Working principle of each component

[0098] (1) H9118 chip U1, core component: It is the core chip of DC-DC step-down converter, which integrates switching transistors and control circuits. It regulates the output voltage by controlling the on and off time of the internal switching transistors. When the switching transistor is on, the current passes through the inductor to store energy; when the switching transistor is off, the inductor releases energy to maintain the output voltage.

[0099] Feedback regulation: The chip's FB pin is used to receive a feedback signal of the output voltage. By comparing it with the internal reference voltage of the chip, the chip automatically adjusts the duty cycle of the switching transistor to ensure that the output voltage is stable at the set value of 3.8V.

[0100] Enable control: The EN pin is the enable pin, which can control whether the chip works through components such as R14. When the EN pin is high, the chip works normally; when it is low, the chip enters a low-power standby state.

[0101] (2) L1, Energy Storage and Energy Conversion: During the conduction period of the switching transistor, the inductor stores energy. At this time, the current gradually increases, and the electrical energy is converted into magnetic energy and stored in the inductor. When the switching transistor is turned off, the magnetic energy in the inductor is converted into electrical energy, releasing energy to maintain the stability of the output current and help maintain the output voltage.

[0102] (3) C18 and C23, low-frequency filtering: Large-capacity electrolytic capacitors have good low-frequency characteristics and are used to filter out low-frequency ripple in the output voltage, making the output voltage smoother and more stable. C18 mainly filters the output 3.8V voltage, while C23 filters the input 12V voltage, reducing the impact of power input fluctuations on the circuit.

[0103] (4) C19, C20, C24, C25, high frequency filtering: ceramic capacitors have good impedance characteristics for high frequency signals, which can effectively filter out high frequency ripple and noise generated when the switching power supply is working, and further improve the purity of the output voltage.

[0104] (5) R14, Enable control: Connected to the EN pin of the chip, it is used to set the enable conditions of the chip. By cooperating with other circuits, it can realize the control of the chip's working state, such as undervoltage protection.

[0105] (6) R15, reserved function: can be reserved to meet the needs of different application scenarios. In some cases, soldering this resistor can change some parameters or functions of the circuit.

[0106] (7) R16 and R17, feedback voltage divider: These form a voltage divider circuit to sample the output voltage and feed the sampled voltage signal back to the FB pin of the chip. By adjusting the resistance values ​​of these two resistors, the output voltage can be set. According to the voltage divider principle, VFB = VBAT * [R17 / (R16+R17)], the chip adjusts the duty cycle based on this feedback voltage to achieve a stable output of 3.8V.

[0107] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An IoT intercom host adapter board circuit, characterized in that, include: The core control chip U2 uses the ML160 chip to realize the core control and communication functions of the device; The host interface circuit is connected to the core control chip U2 and is used to transmit audio signals and serial communication with the host motherboard, as well as for power connection. The SIM card circuit, connected to the core control chip U2, provides power, clock, reset, and data transmission conditions for the USIM card, enabling data interaction with external devices. The software programming circuit is connected to the core control chip U2 and is used to realize USB data transmission and power supply between devices; The voltage regulator circuit, connected to the core control chip U2, is used to step down the 12V input voltage to the 3.8V output.

2. The IoT intercom host adapter board circuit according to claim 1, characterized in that: The core control chip U2 has a capacitor C32 and a resistor R13 connected to pin 46. The resistor R13 is connected to a capacitor C33, a bidirectional diode D10, and an antenna ANT.

3. The IoT intercom host adapter board circuit according to claim 1, characterized in that: The host interface circuit includes connector J1; Pin 1 of connector J1 is connected to diode D1, and pins 3 and 4 of connector J1 are connected to pins 33 and 34 of core control chip U2. The connector J1 has a 6-pin connector connected to one end of a capacitor C4. The other end of the capacitor C4 is connected to capacitors C11 and C12 and a resistor R4. The resistor R4 is connected to pin 24 of the core control chip U2. The connector J1 has one end of capacitor C3 connected to pin 7. The other end of capacitor C3 is connected to capacitors C9 and C10 and resistor R3. Resistor R3 is connected to pin 23 of the core control chip U2. The connector J1 has its 8th pin connected to one end of capacitor C2, and the other end of capacitor C2 is connected to capacitors C7 and C8 and resistor R2. Resistor R2 is connected to pin 22 of the core control chip U2. The connector J1 has a capacitor C1 connected to one end of its 9th pin. The other end of the capacitor C1 is connected to capacitors C5 and C6 and resistor R1. Resistor R1 is connected to pin 21 of the core control chip U2.

4. The IoT intercom host adapter board circuit according to claim 1, characterized in that: The SIM card circuit includes a SIM slot 1; Pin 1 of the SIM1 slot is connected to a bidirectional diode D5, a capacitor C16 and a resistor R8, and the resistor R8 is connected to pin 6 of the core control chip U2. Pin 2 of the SIM1 card slot is connected to a bidirectional diode D4, a capacitor C15 and a resistor R7, and the resistor R7 is connected to pin 5 of the core control chip U2. The SIM1 card slot has a bidirectional diode D3, a capacitor C14 and a resistor R6 connected to pin 4. The resistor R6 is connected to pin 7 of the core control chip U2. Pin 6 of the card slot SIM1 is connected to a bidirectional diode D2, capacitor C13, and resistor R5, and is connected to pin 8 of the core control chip U2. The other end of the resistor R5 is connected to pin 1 of the card slot SIM1.

5. The IoT intercom host adapter board circuit according to claim 1, characterized in that: The software programming circuit includes a Type-C interface connector J3; Pins A4 and A9 of the Type-C interface connector J3 are connected, and pin A9 of the Type-C interface connector J3 is connected to diode D8 and capacitor C17. The Type-C interface connector J3 has a resistor R9 connected to pin A5. The Type-C interface connector J3 has a diode D6 connected to pin A6, which is also connected to pin 26 of the core control chip U2. The Type-C interface connector J3 has a diode D7 connected to pin A7, which is connected to pin 27 of the core control chip U2.

6. The IoT intercom host adapter board circuit according to claim 5, characterized in that: The B9 and B4 pins of the Type-C interface connector J3 are connected and connected to pin 28 of the core control chip U2; Pins B7 and B6 of the Type-C interface connector J3 are connected to pins 27 and 26 of the core control chip U2, respectively. The B5 pin of the Type-C interface connector J3 is connected to a resistor R10.

7. The IoT intercom host adapter board circuit according to claim 1, characterized in that: The voltage regulator circuit includes a DC-DC converter chip U1; A capacitor C21 is connected between pins 2 and 6 of the chip U1; Pin 2 of the chip U1 is also connected to one end of an inductor L1, and the other end of the inductor L1 is connected to capacitors C25, C24, C23, resistor R16, and resistor R17. The chip U1 has capacitors C20, C19 and C18 connected to pin 3. Pin 5 of the chip U1 is connected to resistors R14 and R15.

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