A multifunctional PPS pulse-per-second signal generator based on SoC

Abstract

A multifunctional PPS pulse-per-second signal generator based on an SoC relates to the technical field of satellite timing. It addresses the existing problem that actual satellite signals are limited by factors such as satellite visibility, signal strength, and environmental interference, resulting in inevitable errors during testing and verification. The timing process is not intuitive and flexible, and compared to the SoC core, other main control cores have fewer resources, making it unable to cope with various timing situations and different devices requiring timing. The present invention includes a power supply circuit, an SoC main control circuit, an RS422 bus transmission circuit, a CAN bus transmission circuit, an OLED display circuit, a key circuit, a bidirectional voltage conversion circuit, a DIP switch, and wiring terminals. The present invention simulates satellite signals to generate pulse signals and time information, uses RS422 and CAN bus data transmission, and improves the signal generator's anti-interference capability.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite timing, and in particular to a multifunctional PPS pulse-per-second signal generator based on SoC (System on Chip). Background Art

[0002] Satellite navigation systems such as the Global Positioning System (GPS) and the Beidou Navigation Satellite System (BDS) are now widely used in both civilian and commercial sectors. Beyond positioning and navigation, these systems also provide high-precision time synchronization, which is crucial for power systems, communications networks, financial transactions, and scientific research. To test and verify the performance of various devices when receiving and processing satellite signals, signal generators that simulate satellite signals for timing have emerged.

[0003] With the booming aerospace industry and advancements in electronic communications, more and more practical applications require timing for testing and verification, and the time information and other data received must be more accurate. Currently, timing devices primarily use satellite signal receivers to receive satellite signals, process the data, and transmit it for timing. However, real satellite signals are limited by factors such as satellite visibility, signal strength, and environmental interference, which can introduce inevitable errors during testing and verification. The timing process is not intuitive and flexible, and compared to other main control cores in the SoC core, it has fewer resources and cannot cope with various timing scenarios and different devices requiring timing. Signal generators that simulate satellite signals can generate controllable and accurate satellite signals in a laboratory environment, resulting in more accurate results for testing and verification. Furthermore, buttons, displays, and other devices allow for visualization and high customization of timing methods, transmission speeds, and real-time timing processes, greatly meeting diverse timing requirements. This is essential for developing, optimizing, and troubleshooting existing systems.

[0004] In short, signal generators that simulate satellite signals for timing play an important role in modern technologies such as aerospace, providing reliable testing and verification methods for various applications that require timing. Summary of the Invention

[0005] The present invention aims to solve the problems in the prior art that real satellite signals are limited by factors such as satellite visibility, signal strength and environmental interference, which inevitably lead to errors in the test and verification process. The timing process is not intuitive and flexible, and compared with the SoC core, other main control cores have fewer resources and cannot cope with various timing situations and different devices requiring timing. A multifunctional PPS second pulse signal generator based on SoC is provided to solve the problems.

[0006] A multifunctional PPS pulse-per-second signal generator based on SoC, comprising an SoC main control circuit, a bidirectional voltage conversion circuit, an RS422 bus transmission circuit, a CAN bus transmission circuit, an OLED display circuit, a key circuit, a dip switch, and wiring terminals;

[0007] The SoC main control circuit is used to simulate and generate PPS second pulse signals, UTC time information, receive key circuit information and drive the OLED display circuit for display;

[0008] The RS422 bus transmission circuit is used to send PPS second pulse signals or select to send UTC time information; the CAN bus transmission circuit is used to send UTC time information;

[0009] The OLED display circuit is used to display current information, including time information, CAN bus information and modifiable mode prompt information;

[0010] The button circuit cooperates with the OLED display circuit and the SoC main control circuit to switch the menu, select and preset the initial function data of the screen;

[0011] The bidirectional voltage conversion circuit realizes the conversion of voltage between circuits according to the different circuit power supply voltages; the dip switch selects the corresponding dip switch through the module switching prompt on the screen, and switches different mode ports according to the displayed prompt information;

[0012] The terminal block serves as a data connection port for the required timing equipment, generates a PPS pulse-per-second signal and UTC time information by simulating satellite signals, and transmits the generated signal data through the signal generator to perform accurate timing work.

[0013] Beneficial effects of the present invention:

[0014] The signal generator described in this invention leverages the high-speed processing capabilities of the SoC to achieve precise time control of the PPS pulse-per-second signal, ensuring the signal's frequency accuracy. It also outputs time information data immediately upon the falling edge of the PPS pulse-per-second signal, achieving synchronized output of the PPS signal and time information.

[0015] To improve signal anti-interference performance, the present invention uses RS422 and CAN buses to transmit pulse-per-second signals and time information, ensuring signal stability and reliability. Furthermore, through DIP switches and key settings, signal channels can be easily switched on and off, as well as parameter configurations. Multiple ports can be provided for signal data transmission, enhancing the device's flexibility and applicability.

[0016] The present invention also provides an intuitive visual operation interface, where key information and operations are displayed visually on the screen, greatly simplifying the operation process and reducing the difficulty of use. Therefore, the multifunctional PPS pulse-per-second signal generator based on the present invention has the advantages of high precision, anti-interference, high flexibility and visualization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of the circuit functional structure of a multifunctional PPS pulse-per-second signal generator based on SoC described in the present invention.

[0019] Figure 2 This is a flow chart of the OLED display module of the SoC-based multifunctional PPS pulse per second signal generator SoC main control circuit described in the present invention.

[0020] Figure 3 This is a schematic diagram of the key arrangement of the multifunctional PPS pulse per second signal generator based on SoC described in the present invention.

[0021] Figure 4 This is a flowchart of the key part of the multifunctional PPS pulse-per-second signal generator based on SoC described in the present invention; (a) is a flowchart of the key circuit; (b) is a flowchart of controlling the system timing by pressing the key when the system is in timing.

[0022] Figure 5 This is a schematic diagram of the modules and signal flow relationships of the SoC main control circuit of the multifunctional PPS pulse per second signal generator based on SoC described in the present invention.

[0023] Figure 6 This is a timing diagram of the PPS pulse-per-second differential signal of the multifunctional PPS pulse-per-second signal generator based on SoC described in the present invention.

[0024] Figure 7 This is a flow chart of the pulse-per-second signal generator module and the UTC time information generation module of the SoC main control circuit of a multifunctional PPS pulse-per-second signal generator based on SoC described in the present invention; (a) is a flow chart of the pulse-per-second signal generator module; (b) is a flow chart of the UTC time information generation module.

[0025] Figure 8This is a timing diagram of the PPS pulse per second signal generator based on SoC and data synchronization described in the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] It should be noted that references to "one embodiment," "an embodiment," "an example embodiment," etc., in this specification indicate that the described embodiment may include specific features, structures, or characteristics. However, not every embodiment must include these specific features, structures, or characteristics. In addition, such references do not necessarily refer to the same embodiment. Furthermore, when specific features, structures, or characteristics are described in conjunction with an embodiment, whether or not explicitly described, it is indicated that it is within the knowledge of those skilled in the art to incorporate such features, structures, or characteristics into other embodiments.

[0028] In addition, certain words are used in the specification and subsequent claims to refer to specific components or parts. It should be understood by those with ordinary knowledge in the relevant field that manufacturers may use different nouns or terms to refer to the same component or part. This specification and subsequent claims do not use differences in names as a way to distinguish components or parts, but rather use differences in the functions of components or parts as the criteria for distinction. The words "including" and "comprising" mentioned throughout the specification and subsequent claims are open-ended terms and should be interpreted as "including but not limited to". In addition, the word "connect" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0029] This embodiment provides a multifunctional SoC-based PPS signal generator that simulates satellite signals to generate PPS signals and UTC time information. The generated signals are transmitted via RS422 and CAN buses. The generated PPS signals are highly synchronized with the current time information, enabling the generation of controllable, accurate GPS signals in laboratory environments. This allows for more accurate testing and verification results, meeting the precise timing requirements of most scientific and industrial testing environments.

[0030] like Figure 1 As shown, the multifunctional PPS pulse per second signal generator based on SoC includes a power supply circuit, an SoC main control circuit, an RS422 bus transmission circuit, a CAN bus transmission circuit, an OLED display circuit, a button circuit, a bidirectional voltage conversion circuit, a dip switch and a wiring terminal;

[0031] The power supply circuit supplies power to each circuit;

[0032] The SoC main control circuit is used to simulate and generate PPS second pulse signals, UTC time information, receive key circuit information and drive the OLED display circuit for display;

[0033] The RS422 bus transmission circuit transmits the PPS pulse-per-second signal and can also optionally transmit the UTC time information;

[0034] The CAN bus transmission circuit transmits UTC time information;

[0035] The OLED display circuit is used to display current information, including time information, CAN bus information, modifiable mode prompt information, etc.

[0036] The button circuit, in conjunction with the OLED display circuit and the SoC main control circuit, is used for menu switching, selection, and initial function data preset on the screen;

[0037] The bidirectional voltage conversion circuit has different power supply voltages for different circuits. In order to meet the information exchange between different circuits, voltage conversion is required between different circuits for connection;

[0038] The DIP switch selects the corresponding DIP switch through the module switching prompt on the screen, and switches to different mode ports according to the displayed prompt information;

[0039] The terminal block is the data connection hole for the required timing equipment. By simulating satellite signals, a PPS pulse-per-second signal and UTC time information are generated, and the signal generator transmits the generated signal data to perform accurate timing work.

[0040] In this embodiment, the power supply circuit requires a 12V power input, which is converted to the required voltages by a voltage conversion chip within the power supply circuit. Specifically, the 12V voltage is converted to 5V, 3.3V, and 1.5V to power the various circuits. A 50MHz external crystal oscillator is used, and a phase-locked loop (PLL) is used to generate 10MHz and 50MHz frequency clocks for the various modules within the SoC's main control circuit.

[0041] In this embodiment, the RS422 bus transmission circuit primarily comprises four RS422 drivers, two RS422 transmitter circuits, and two RS422 receiver circuits. Each circuit has four channels connected to terminal blocks, transmitting the PPS pulse-per-second signal and UTC time information. The differential output improves signal interference resistance and stability, ensuring data accuracy.

[0042] The RS422 bus transmission circuit includes two pairs of RS422 transceiver circuits, four for transmission and four for reception. To meet different timing requirements, one pair of RS422 transceiver circuits uses a 3.3V power supply, while the other pair uses a 5V power supply. One end is connected to the pins of the main control chip in the SoC main control circuit, and the other end is connected to the wiring terminal. Because the pins of the main control chip can only input and output 3.3V voltage signals, a bidirectional voltage conversion circuit is installed between the SoC main control circuit and the 5V RS422 transceiver circuit. The 5V voltage is bidirectionally converted to 3.3V to prevent pin damage.

[0043] In this embodiment, the CAN bus transmission circuit includes a CAN bus controlled by two CAN control circuits. The channel to be transmitted can be selected according to the dip switch, and the UTC time information is sent through the CAN bus protocol. The differential line output improves the anti-interference and stability of the signal data, ensuring the accuracy of the data.

[0044] The CAN bus transmission circuit includes two CAN control circuits and four CAN transceiver circuits. To meet different timing requirements, the CAN transceiver circuits include two 5V voltage and two 3.3V voltage power supply types, and each CAN control circuit can control two different voltage types of CAN transceiver circuits. All CAN transceiver circuits can also be directly connected to the SoC main control circuit, and the SoC main control circuit can directly transmit and receive CAN bus data. The above connection conditions can all be selected by the DIP switch. Because the CAN control circuits are all powered by 5V, 5V and 3.3V bidirectional voltage conversion circuits are used when connecting to the SoC main control circuit and the CAN transceiver circuit for signal transmission.

[0045] In this embodiment, the OLED display circuit is mainly used to display various status information, such as: menu page, display of current UTC time information, baud rate of CAN bus, description and prompts of various modes of DIP switch, etc.

[0046] The OLED display circuit uses an IIC communication OLED display screen. The OLED display module in the SoC main control circuit transmits data to the OLED display circuit for display via the IIC protocol. The software flow is as follows Figure 2 As shown:

[0047] First, the OLED display is initialized. After the initialization is completed, it is determined whether a key signal is detected. If so, the display switches prompt information. The display menu displays prompt information of preset information and mode by pressing the key; then it is determined whether the preset information is set by pressing the key. If so, the preset information can be preset by pressing the key. After the information is preset, the preset information that has been set is displayed; finally, when the system starts to synchronize time, the OLED synchronously displays the real-time information of the system.

[0048] In this embodiment, the button circuit includes multiple buttons, which are used in conjunction with other circuits such as the OLED display circuit. The pages can be switched by buttons according to the menu page, and operations such as up, down, left, right, confirm, and return can be performed. Other preset information can also be set by buttons, such as setting the baud rate of the CAN bus and pausing and starting sending during timing.

[0049] like Figure 3 As shown, the key circuit is mainly divided into five keys, Figure 3 As shown in the arrangement, when the button is pressed, a high level is sent to the corresponding pin of the main control chip of the SoC main control circuit, and the high level is transmitted to the satellite signal generation module, OLED display module and CAN bus control module in the SoC main control circuit. Figure 3 As shown in the arrangement, button SW2 is up, button SW4 is down, button SW5 is left (return), button SW1 is right, and button SW3 is confirm. Figure 4 As shown in (a), the system initializes. Pressing a button, after key debounce processing, displays real-time system information, changes CAN bus parameters, and sets the initial UTC time. Specifically, through the cooperation of the CAN bus control module, preset settings such as the CAN bus baud rate, CAN bus drive mode, and the IDs used to identify other bus devices can be changed. The UTC time generator module can also be used to set the initial UTC time. Furthermore, the OLED display module can be controlled to switch between different menu pages and display real-time information from the PPS signal generator. The system then determines whether it has started timing. If so, it transmits the PPS pulse-per-second signal and UTC time information. Otherwise, the system returns to initialization.

[0050] like Figure 4 As shown in (b) in the figure, when the system is synchronizing time, you can also control the stop or continue of the system timing by pressing a button.

[0051] In this embodiment, the bidirectional voltage conversion circuit is connected to different power supply circuits to convert the voltage into the voltage corresponding to the different power supply circuits, thereby preventing the signal pins from being damaged by the voltage.

[0052] The bidirectional voltage conversion circuit contains 6 8-channel bidirectional voltage conversion chips, which are respectively connected to the SoC main control circuit, CAN control circuit, RS422 transceiver circuit and CAN transceiver circuit. Different circuits use different power supply voltages. The bidirectional voltage conversion circuit converts different voltage signals 3.3V and 5V in both directions, so that different circuits receive corresponding voltage signals for data transmission, preventing damage to hardware signal pins and ensuring stable signal transmission.

[0053] In this embodiment, the DIP switch selects the CAN bus data transmission channel by toggling the switch, meeting the timing requirements of different devices by switching between different transmission channels. Specifically, the DIP switch controls the connection between the 3.3V CAN transceiver circuit and the CAN control circuit, the connection between the 5V CAN transceiver circuit and the CAN control circuit, and the direct connection between the CAN transceiver circuit and the SoC main control circuit. Mode selection is performed by toggling the DIP switch, and each mode is indicated by the OLED display circuit.

[0054] In this embodiment, the wiring terminals are mainly used for RS422 and CAN data communication transmission ports. The wiring terminals are respectively connected to each bus channel, and signals and data are transmitted to other devices that need timing through the wiring terminals.

[0055] like Figure 5 As shown, in this embodiment, the SoC main control circuit includes a second pulse signal generation module, a UTC time signal generation module, a CAN bus control module and an OLED display module;

[0056] The second pulse signal generating module is used to generate a PPS second pulse signal and transmit the rising edge signal of the generated PPS second pulse signal to the UTC time information generating module and the CAN bus control module;

[0057] The UTC time signal generating module is used to generate UTC time information and transmit it to the CAN bus control module and the OLED display module;

[0058] The CAN bus control module is used to control the sending time information and reading data of the CAN control circuit by configuring the UTC time information in the register of the CAN controller of the CAN control circuit;

[0059] The OLED display module includes four parts: an OLED initialization part, which is used to initialize the OLED display screen of the OLED display circuit; an OLED data output part, which is used to output the data information that the OLED needs to display; an OLED control part, which is used to control the display of the OLED display circuit; and an IIC drive part. The information interaction between the OLED display circuit and the SoC main control circuit is transmitted through the IIC protocol.

[0060] In this embodiment, the pulse-per-second signal generation module and the UTC time signal generation module simulate a 10 MHz clock to generate a PPS pulse-per-second signal and UTC time information. These signals are transmitted to the RS422 bus transmission circuit and the CAN bus transmission circuit, respectively, via the RS422 bus protocol and the CAN bus protocol. UTC time information and other relevant information are also transmitted to the OLED display module via the internal logic of the SoC main control circuit, driving the OLED display circuit to display current PPS signal generator information, including time information, baud rate, and the ID of the device currently receiving data on the bus. The module also receives signals from the keypad module to switch menu display, select options, and other operations. Furthermore, through coordination with the CAN bus control module, it can change preset settings such as the CAN bus baud rate, CAN bus driver mode, and the IDs of other bus devices.

[0061] In this embodiment, the UTC signal generating module and the second pulse signal generating module use a divided clock 10MHZ clock input. When powered on or reset, the module is initialized. After the initialization is completed, the initial value of the PPS second pulse is 0, and the internal counter of the module starts counting the clock cycle.

[0062] like Figure 6 and Figure 7 As shown in the figure, the PPS pulse signal is composed of a high level of 1ms and a low level of 999ms, and the clock period of 10MHZ frequency is 100ns. Figure 7 As shown in (a), the counter counts up by 1 every 100ns clock cycle. When the counter counts to 9999, that is, after 1ms, the PPS second pulse is set to 1, and the counter continues counting. When the time passes another 999ms, the PPS second pulse level is pulled low, and the counter is cleared to 0 and counts again. Thus, a 1s second pulse signal is generated, and the next step is carried out.

[0063] Since the UTC time information and the second pulse need to be synchronized, the PPS second pulse needs to be delayed by one cycle to align the timing and achieve the purpose of time synchronization. After the PPS second pulse is delayed by one cycle, it is sent through the RS422 bus. The rising edge of the undelayed PPS second pulse signal is taken and transmitted to the UTC time generation module, such as Figure 7 As shown in (b), the UTC time defaults to 0, and the initial value can be set by pressing the button. When the rising edge of the PPS second pulse is detected, the UTC time is increased by 1, thereby simulating the generation of the UTC time signal.

[0064] After the UTC time simulation is generated, the generated information is transmitted to the CAN control circuit. The CAN control circuit controls the CAN transceiver circuit to send the UTC time information data through the CAN bus protocol, and sends it synchronously with the PPS second pulse to perform accurate time synchronization.

[0065] like Figure 8 As shown, in this embodiment, when the PPS pulse per second rises, the time information data starts to be sent through the CAN bus, and it only takes 260us for the time information data to be sent.

[0066] In this embodiment, a counter in the pulse-per-second signal generator module within the SoC's main control circuit counts clock cycles, enabling precise time control of each pulse-per-second signal cycle and ensuring signal frequency accuracy. The PPS pulse-per-second signal is then transmitted with a delay of one cycle. This allows the PPS signal to be aligned with the UTC time signal within a single clock cycle, thus ensuring signal time accuracy. Furthermore, the signal data transmission is extremely fast: upon the rising edge of the PPS pulse-per-second signal, the UTC time data transmission is completed 260µs later, ensuring extremely low latency for the PPS pulse-per-second signal generator.

[0067] This embodiment uses RS422 and CAN bus to transmit second pulse signals and time information, ensuring the stability and reliability of the signal. In addition, through the setting of the dial switch and button, it is possible to easily switch or control the opening and closing of the signal channel, as well as to configure the parameters, and provide multiple ports for sending signal data, thereby enhancing the flexibility and applicability of the device. The present invention also provides an intuitive visual operation interface, and key information and operations can be intuitively displayed on the screen, which greatly simplifies the operation process and reduces the difficulty of use. Therefore, the multifunctional PPS second pulse signal generator based on SoC of the present invention has the advantages of high precision, anti-interference, high flexibility and visualization.

[0068] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. Multifunctional PPS pulse-per-second signal generator based on SoC, characterized by: The signal generator includes a SoC main control circuit, a bidirectional voltage conversion circuit, an RS422 bus transmission circuit, a CAN bus transmission circuit, an OLED display circuit, a button circuit, a dip switch and a wiring terminal; The SoC main control circuit is used to simulate and generate PPS second pulse signals, UTC time information, receive key circuit information and drive the OLED display circuit for display; The RS422 bus transmission circuit is used to send PPS pulse-per-second signals or select to send UTC time information; the CAN bus transmission circuit is used to send UTC time information; The OLED display circuit is used to display current information, including time information, CAN bus information and modifiable mode prompt information; The button circuit cooperates with the OLED display circuit and the SoC main control circuit to switch the menu, select and preset the initial function data of the screen; The bidirectional voltage conversion circuit realizes voltage conversion between circuits according to the different power supply voltages of the circuits; The DIP switch selects the corresponding DIP switch through the module switching prompt on the screen, and switches to different mode ports according to the displayed prompt information; The terminal block serves as a data connection port for the required timing equipment, generates a PPS pulse-per-second signal and UTC time information by simulating satellite signals, and transmits the generated signal data through the signal generator to perform accurate timing work.

2. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: It also includes a power supply circuit, which has a 12V power input and converts the voltage into the required voltage through a voltage conversion chip in the power supply circuit to power various circuits.

3. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The SoC main control circuit includes a second pulse signal generation module, a UTC time information generation module, a CAN bus control module and an OLED display module; The second pulse signal generating module is used to generate a PPS second pulse signal and transmit the rising edge signal of the PPS second pulse signal to the UTC time information generating module and the CAN bus control module; The UTC time information generating module is used to generate UTC time information and transmit it to the CAN bus control module and the OLED display module; The CAN bus control module is used to control the sending time information and reading data of the CAN control circuit by configuring the UTC time information in the register of the CAN controller of the CAN control circuit; The OLED display module includes four parts: an OLED initialization part for initializing the OLED display screen of the OLED display circuit; an OLED data output part for outputting data information required to be displayed by the OLED; The OLED control part is used to control the display of the OLED display circuit; the IIC drive part transmits the information interaction between the OLED display circuit and the SoC main control circuit through the IIC protocol.

4. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The RS422 bus transmission circuit includes two pairs of RS422 transceiver circuits, one pair of RS422 transceiver circuits is powered by a 3.3V voltage, and the other pair of RS422 transceiver circuits is powered by a 5V voltage; one end of the RS422 transceiver circuit is connected to the main control chip pin in the SoC main control circuit, and the other end is connected to the wiring terminal; a bidirectional voltage conversion circuit is set between the SoC main control circuit and the 5V RS422 transceiver circuit to realize bidirectional conversion of 5V voltage to 3.3V.

5. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The CAN bus transmission circuit includes a CAN bus controlled by two CAN control circuits, and the CAN bus to be transmitted is selected according to the DIP switch, and the UTC time information is sent through the CAN bus protocol; The CAN bus transmission circuit includes two CAN control circuits and four CAN transceiver circuits. Each CAN transceiver circuit includes two power supply types, namely 5V voltage and 3.3V voltage, and each CAN control circuit controls two CAN transceiver circuits with different voltage types, or all CAN transceiver circuits are directly connected to the SoC main control circuit, and the SoC main control circuit directly transmits and receives CAN bus data; both situations are selected by the dip switch; When the CAN control circuit is connected to the SoC main control circuit and the CAN transceiver circuit, a 5V and 3.3V bidirectional voltage conversion circuit is used for signal transmission.

6. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The OLED display circuit uses an OLED display screen with IIC communication. The OLED display module in the SoC main control circuit transmits data to the OLED display circuit through the IIC protocol for display. The specific process is as follows: The OLED display is initialized. After initialization is completed, it determines whether a key signal is detected. If so, the display switches prompt information. The display menu displays prompt information of preset information and mode by pressing the key; then it determines whether the preset information is set by pressing the key. If so, the preset information is preset by pressing the key. After the information is preset, the preset information that has been set is displayed; finally, when the system starts to serve time, the OLED synchronously displays the real-time information of the system.

7. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The button circuit includes multiple buttons that are used in conjunction with other circuits to switch pages according to the menu page, perform up, down, left, right, confirm, return operations, or set other preset information through buttons.

8. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The bidirectional voltage conversion circuit includes a plurality of bidirectional voltage conversion chips connected to different power supply circuits to convert voltages corresponding to the different power supply circuits.

9. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The DIP switch is used to select the data transmission channel of the CAN bus by toggling the DIP switch, and the timing requirements of different devices are met by switching different transmission channels.

10. The multifunctional PPS pulse per second signal generator based on SoC according to claim 1, characterized in that: The wiring terminals are used for RS422 and CAN data communication transmission ports.

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