4G network mobile station base module adaptive to serial port RTK module

Abstract

The utility model discloses a 4G network mobile station base module adaptive to a serial port RTK module, which relates to the technical field of GNSS positioning and comprises a single chip microcomputer system circuit, a display screen circuit, a Bluetooth circuit, a channel control circuit and a 4G communication circuit which are integrated on the same circuit board. Wherein the single-chip microcomputer system circuit comprises a single-chip microcomputer minimum system circuit, the single-chip microcomputer minimum system circuit comprises a single-chip microcomputer, the display screen circuit, the Bluetooth circuit and the channel control circuit are connected to the single-chip microcomputer, the channel control circuit comprises an analog switch chip and an RTK base circuit which are connected with each other, and the 4G communication circuit is connected with the analog switch chip. And the RTK base circuit is connected with an external serial port RTK module. The network RTK mobile station can be matched with an RTK module with a serial port function, RTK module communication switching is carried out through the channel control circuit, and the network RTK mobile station function which is high in compatibility, flexible and convenient is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of GNSS positioning, and in particular to a 4G network mobile station base module adapted to a serial port RTK module. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] RTK (Real-time kinematic) carrier phase differential technology is a common technology in the field of GNSS positioning. It achieves centimeter-level positioning accuracy by processing the observed values ​​of the carrier phase of two reference measurement stations in real time. With this positioning technology, it is necessary to set up a reference station, a mobile station and related communication equipment to work, and its working range is limited. At present, network RTK is an improved RTK technology that is widely used. It is a real-time differential positioning system that uses a multi-reference station network, also known as multi-reference station RTK technology. This technology is an improvement on the ordinary RTK method. It connects multiple surrounding CORS reference stations through the network to achieve real-time differential positioning. Network RTK can overcome the shortcomings of conventional RTK, does not require the establishment of a special reference station, and can achieve long-distance RTK positioning more quickly.

[0004] However, the secondary development of RTK software and hardware is currently limited and costly, making it difficult to meet the expansion needs of high-precision positioning and high flexibility in detection application scenarios carried out by robots and drones. The functional compatibility of existing network RTK mobile stations is poor. Utility Model Content

[0005] In view of the above-mentioned problems and defects in the prior art, the utility model provides a 4G network mobile station base module adapted to a serial port RTK module, which can be adapted to an RTK module with a serial port function, configure the 4G network CORS server through Bluetooth, connect to the CORS server base station through the 4G network, and then switch the RTK module communication through the channel control circuit, and use the RTK technology to display the positioning status in real time, thereby realizing a network RTK mobile station function with strong compatibility, flexibility and convenience.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A 4G network mobile station base module adapted to a serial port RTK module, comprising a single-chip system circuit, a display circuit, a Bluetooth circuit, a channel control circuit and a 4G communication circuit integrated on the same circuit board;

[0008] Among them, the single-chip microcomputer system circuit includes a single-chip microcomputer minimum system circuit, the single-chip microcomputer minimum system circuit includes a single-chip microcomputer, the display screen circuit, the Bluetooth circuit, and the channel control circuit are respectively connected to the single-chip microcomputer, the channel control circuit includes an analog switch chip and an RTK base circuit connected to each other, the 4G communication circuit is connected to the analog switch chip, and the RTK base circuit is connected to an external serial port RTK module.

[0009] According to a further technical solution, the single-chip microcomputer system circuit also includes a custom button, an SD memory card circuit and a burning circuit connected to the single-chip microcomputer minimum system circuit; the display screen circuit includes a TFT display screen module and a brightness adjustment circuit connected to each other; the Bluetooth circuit includes a Bluetooth module and a Bluetooth enabling circuit; and the 4G communication circuit includes a 4G module and a reset circuit connected to each other.

[0010] According to a further technical solution, the TFT display screen module, the Bluetooth module, the Bluetooth enabling circuit, the analog switch chip, the RTK base circuit and the reset circuit are all connected to the single-chip microcomputer.

[0011] A further technical solution is that the single-chip microcomputer minimum system circuit includes a crystal oscillator and peripheral circuits connected to the single-chip microcomputer; the custom button is a self-reset button, and the self-reset button is connected to the single-chip microcomputer and GND; the SD memory card circuit includes an SDIO interface chip, and the SDIO interface chip is connected to the single-chip microcomputer; the burning circuit adopts SW serial debugging mode, including a burning port terminal, and the burning port terminal is connected to the single-chip microcomputer.

[0012] According to a further technical solution, the TFT display module adopts a TFT color display, and the TFT color display adopts an SPI interface; the brightness adjustment circuit is a power supply switching circuit, and the power supply switching circuit includes a switching switch, and the switching switch connects the TFT color display, a 5V power supply, and a 3.3V power supply.

[0013] According to a further technical solution, the Bluetooth module supports SPP Bluetooth and BLE Bluetooth protocols, and the Bluetooth enabling circuit is used to control the turning on and off of the Bluetooth module.

[0014] A further technical solution is that the common port of the analog switch chip is connected to the 4G communication circuit, the normally closed port is connected to the single-chip microcomputer, and the normally open port is connected to the RTK base circuit. The single-chip microcomputer is used to control the switching of the 4G communication circuit and the RTK base circuit.

[0015] A further technical solution also includes a power supply circuit integrated on the same circuit board; the power supply circuit includes a lithium battery charging / power supply circuit, a DC-5V circuit, a DC-3.3V circuit, and an ADC circuit. The power supply circuit is connected to the single-chip system circuit, the display circuit, the Bluetooth circuit, the channel control circuit, and the 4G communication circuit to supply power to each circuit part.

[0016] In a further technical solution, the lithium battery charging / power supply circuit includes a lithium battery, a power switch, and a charging circuit; the lithium battery charging / power supply circuit is connected to a DC-5V circuit, a DC-3.3V circuit, and an ADC circuit;

[0017] The lithium battery is connected to a power switch, which is a self-locking switch. The charging circuit is connected to the lithium battery. A charging indicator light and a charging interface are provided in the charging circuit, and the charging interface adopts a Type-C interface.

[0018] A further technical solution is that the DC-5V circuit is a boost circuit, the input end of the DC-5V circuit is connected to the lithium battery charging / power supply circuit, and the output end of the DC-5V circuit is connected to the 5V port as a 5V electrical output end;

[0019] The DC-3.3V circuit is a step-down circuit, the input end of the DC-3.3V circuit is connected to a 5V port, and the output end of the DC-3.3V circuit is connected to a 3.3V port as a 3.3V power supply output end;

[0020] The ADC circuit includes a reference source circuit and a voltage divider measurement circuit. The reference source circuit is a step-down circuit. The input end of the reference source circuit is connected to a 3.3V port, and the output end of the reference source circuit is connected to a reference source 3V port. The 3.3V port and the lithium battery charging / power supply circuit are respectively connected to the voltage divider measurement circuit. The voltage divider measurement circuit is used to divide the lithium battery voltage and then output it. The power output end of the voltage divider measurement circuit is connected to the single-chip computer system circuit.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] The utility model provides a 4G network mobile station base module adapted to a serial port RTK module, which can be adapted to an RTK module with a serial port function, and has strong adaptability and compatibility; the cost is low, the size is portable, and the 4G network CORS server is configured through Bluetooth, and the secondary development of software and hardware is flexible; the CORS server base station is connected to the 4G network, and the communication between the RTK module and the single-chip microcomputer and the 4G module is switched through the channel control circuit, and physical switching is used to solve the problems of data loss and errors; finally, the RTK technology is used to display the positioning status in real time, so as to realize the network RTK mobile station function with strong compatibility, flexibility and convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0024] Figure 1 This is the overall framework diagram of the 4G network mobile station base module adapted to the serial port RTK module of the utility model;

[0025] Figure 2 It is a circuit connection diagram of the power supply circuit in the utility model;

[0026] Figure 3 It is a circuit connection diagram of the single chip computer system circuit in the utility model;

[0027] Figure 4 It is a circuit connection diagram of the display screen circuit in the utility model;

[0028] Figure 5 It is a circuit connection diagram of the Bluetooth circuit in the utility model;

[0029] Figure 6 It is a circuit connection diagram of the channel control circuit and the 4G communication circuit in the utility model. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] like Figure 1As shown, the utility model discloses a 4G network mobile station base module adapted to a serial port RTK module, including a single-chip system circuit, a display screen circuit, a Bluetooth circuit, a channel control circuit, a 4G communication circuit and a power supply circuit integrated on the same circuit board. Among them, the display screen circuit, the Bluetooth circuit, and the channel control circuit are respectively connected to the single-chip system circuit, the 4G communication circuit is connected to the channel control circuit, and the channel control circuit is connected to an external serial port RTK module; the power supply circuit is connected to the single-chip system circuit, the display screen circuit, the Bluetooth circuit, the channel control circuit, and the 4G communication circuit, and is used to supply power to each circuit part.

[0033] Specifically, the single-chip microcomputer system circuit includes a single-chip microcomputer minimum system circuit, which includes a single-chip microcomputer and a crystal oscillator and peripheral circuits connected thereto. The display circuit, the Bluetooth circuit, and the channel control circuit are respectively connected to the single-chip microcomputer in the single-chip microcomputer system circuit. The channel control circuit includes an analog switch chip and an RTK base circuit connected to each other. The 4G communication circuit is connected to the analog switch chip, and the RTK base circuit is connected to an external serial port RTK module.

[0034] Furthermore, the single-chip system circuit also includes a custom key, an SD memory card circuit, and a burning circuit connected to the single-chip minimum system circuit; the display circuit includes a TFT display module and a brightness adjustment circuit connected to each other; the Bluetooth circuit includes a Bluetooth module and a Bluetooth enabling circuit; and the 4G communication circuit includes a 4G module and a reset circuit connected to each other. The above-mentioned TFT display module, Bluetooth module, Bluetooth enabling circuit, analog switch chip, RTK base circuit, and reset circuit are all connected to the single-chip.

[0035] like Figure 3As shown, the single-chip microcomputer system circuit includes a single-chip microcomputer minimum system circuit, a custom button, a Micro SD memory card circuit and a burning circuit. Among them, the single-chip microcomputer minimum system circuit includes a single-chip microcomputer and a crystal oscillator connected thereto and necessary peripheral circuits, and the single-chip microcomputer minimum system circuit is a core control unit. The single-chip microcomputer U5 model used in the utility model is STM32F407VET6, the crystal oscillator Y1 is 8Mhz, and the pins 2 and 1 of the crystal oscillator Y1 are respectively connected to the pins 12 and 13 of the single-chip microcomputer U5, and are also connected to GND through a 20pF capacitor; the pins 10, 20, 27, 74, 94, 99 of the single-chip microcomputer U5 are connected to GND; the pins 6, 22, 19, 28, 50, 75, 100 of the single-chip microcomputer U5 are connected to the 3.3V port (i.e., the STM-3.3V port ); the VDD pins 11, 19, 22, 28, 50, 75, and 100 of the single-chip computer U5 are connected to the STM-3.3V port together, and are also connected in parallel to 0.1uF capacitors C23, C24, C25, C26, C27, C28, and C29 and then grounded for power decoupling; the pin 21 of the single-chip computer U5 is connected to the VREF+3V port for the ADC external reference source; the pins 14, 49, and 73 of the single-chip computer U5 are connected to 0.1uF, 2.2uF, 2.2uF capacitors C20, C21, and C22 are grounded; pins 25 and 26 of the microcontroller U5 are connected to resistors with a resistance value of 22Ω and then connected to UARTBK_TX and UARTBK_RX ports, which are used to reserve functional serial ports; pins 68 and 69 of the microcontroller U5 are connected to 4G-RXD and 4G-TXD ports, respectively, for communicating with the 4G module in the 4G communication circuit; pins 72 and 76 of the microcontroller U5 are connected to SWDIO and SWSCL ports, respectively, for firmware burning; Pin 33 of MCU U5 is connected to BAT_ADC port for battery voltage ADC acquisition; Pin 64 of MCU U5 is connected to RTK-TXD port for RTK NMEA protocol monitoring and parsing, that is, reading and parsing NMEA protocol data output by RTK to obtain real-time latitude and longitude, number of satellites, positioning mode, etc.; Pins 65, 66, 78, 79, 80, and 83 of MCU U5 are respectively connected to SDIO_D0, SDIO_D1, SDIO_D2, SDIO_D3 and SDIO_SCK and SDIO_CMD ports are used to read and write SD cards; pins 97 and 98 of the microcontroller U5 are connected to the BLE_STA and BLE_EN ports respectively, which are used for Bluetooth status reading and Bluetooth enable control respectively; pin 2 of the microcontroller U5 is connected to the 4G-RESET port for resetting the 4G module; pins 39 to 46 of the microcontroller U5 are connected to BACK0 to BACK7 respectively, which are used to reserve functional pins; pin 95 of the microcontroller U5 is connected to the SWITCH port for controlling the switching of the communication between the 4G module, the RTK module and the microcontroller; pin 96 of the microcontroller U5 is connected to SD_IN for MicroSD card insertion detection; pins 47 and 48 of the microcontroller U5 are connected to BLE_RXD and BLE_TXD respectively for Bluetooth communication; pins 57 to 62 of the microcontroller U5 are connected to TFT_BLK, TFT_CS, TFT_DC, TFT_RST, TFT_SDA, and TFT_SCL respectively for screen display; other pins of the microcontroller U5 are left floating. .

[0036] The above-mentioned custom button SW1 is a self-reset button, which is connected to the microcontroller and GND, and is valid at a low level. Specifically, pins 3 and 4 of the custom button SW1 are connected to GND, and pins 1 and 2 of the custom button SW1 are connected to a 22Ω resistor R6 and then to pin 24 of the microcontroller U5, and at the same time, a 0.1uF capacitor C16 is connected for key jitter filtering.

[0037] The above-mentioned Micro SD memory card circuit includes an SDIO interface chip SD1, which is connected to the single-chip microcomputer. The model of the SDIO interface chip SD1 is DM3AT-SF-PEJM5. Pins 7, 8, 1, 2, 5, and 4 of SD1 are respectively connected to SDIO_D0, SDIO_D1, SDIO_D2, SDIO_D3 and SDIO_SCK and SDIO_CMD ports to achieve connection with the single-chip microcomputer U5; pin 4 of SD1 is connected to the STM-3.3V port, and is connected to the 1uF capacitor C17 and then grounded for power supply filtering; pins 6, 11, 12, and 13 of SD1 are connected to GND; pin 9 of SD1 is connected to the SD_IN port; pins 10 and 14 of SD1 are suspended.

[0038] The above burning circuit adopts SW (Serial Wire Debug) mode, including a 6-pin burning port terminal P2, which is connected to the single-chip computer U5. Specifically, pins 3, 5, and 6 of the burning port terminal P2 are connected to GND; pin 4 of P2 is connected to the STM-3.3V port; pins 1 and 2 of P2 are respectively connected to 22Ω resistors and then connected to SWDIO and SWSCL ports.

[0039] like Figure 4 As shown, the display screen circuit includes a TFT display screen module and a brightness adjustment circuit connected to each other. In the utility model, the above-mentioned TFT display screen module U6 adopts a 1.44-inch TFT color display screen with a resolution of 128×160, and its interface is an SPI interface; Pin 1 of U6 is connected to GND, and Pin 2 of U6 is connected to Pin 2 of the switching switch SW2; A 0.1uF capacitor C30 is connected between Pin 1 and Pin 2 of U6 for power supply filtering; Pins 3, 4, 5, 6, 7, and 8 of U6 are respectively connected to TFT_SCL, TFT_SDA, TFT_RST, TFT_DC, TFT_CS, and TFT_BLK ports. The above-mentioned brightness adjustment circuit is a power supply switching circuit, which includes a switching switch SW2, which is connected to the TFT color display screen, 5V power supply, and 3.3V power supply, and the display screen is switched between 5V and 3.3V power supply by switching switch SW2; Pin 1 of switching switch SW2 is connected to the 5V port, Pin 3 of switching switch SW2 is connected to the STM-3.3V port, and Pins 4 and 5 of switching switch SW2 are connected to GND.

[0040] like Figure 5As shown, the Bluetooth circuit includes a Bluetooth module and a Bluetooth enabling circuit. In the utility model, the model of the Bluetooth module U7 is HC-04, which supports SPP Bluetooth and BLE Bluetooth protocols, and has an onboard PCB antenna. Pin 1 of U7 is connected to GND; Pin 2 of U7 is connected to the BLE_3.3V port, and a 10uF capacitor C31 is also connected to GND for power supply filtering; Pin 3 and Pin 4 of U7 are respectively connected to 22Ω resistors R10 and R11 to BLE_TXD and BLE_RXD ports; Pin 9 of U7 is connected to the BLE_STA port; and the other pins of U7 are left floating. In addition, the Bluetooth enabling circuit is a step-down circuit with enable, which is used to control the opening and closing of the Bluetooth module. The main chip U8 of this circuit is LP5907MFX-3.3 / NOPB. Pin 1 of U8 is connected to the Power_In port, and the 10uF capacitor C32 is connected to GND for power filtering; Pin 2 of U8 is connected to GND; Pin 3 of U8 is connected to the BLE_EN pin for controlling circuit enable; Pin 4 of U8 is left floating; Pin 5 of U8 is connected to the BLE_3.3V port, and two parallel 0.1uF capacitors C33 and C34 are connected for power filtering.

[0041] like Figure 6 As shown, the channel control circuit includes an analog switch chip and an RTK base circuit connected to each other, and the 4G communication circuit includes a 4G module and a reset circuit connected to each other. Among them, the common port of the analog switch chip is connected to the 4G communication circuit, the normally closed port is connected to the single-chip microcomputer, and the normally open port is connected to the RTK base circuit, and the single-chip microcomputer is used to control the switching of the 4G communication circuit and the RTK base circuit. In the utility model, the model of the analog switch chip U10 is TS5A23157DGSR, and the pin 1 and pin 5 of U10 are connected to the SWITCH port for channel switching control; the pin 2 and pin 4 of U10 are respectively connected to the RTK-TXD port and the RTK-RXD port; the pin 3 of U10 is connected to GND; the pin 7 and pin 9 of U10 are respectively connected to the 22Ω resistors R16 and R17 and then connected to the 4G-TXD and 4G-RXD ports; the pin 8 of U10 is connected to the STM-3.3V port, and the 0.1uF capacitor C35 is connected to GND for power supply filtering. In addition, the RTK base circuit includes the RTK chip U11, which is connected using terminals. Pins 2, 5, and 6 of U11 are connected to GND; Pin 1 of U11 is connected to the 5V port, and a 10uF capacitor C37 is connected to GND for power supply filtering; Pins 3 and 4 of U11 are connected to 22Ω capacitors R14 and R15 respectively and then connected to the RTK-RXD and RTK-TXD ports. Here, the RTK-RXD port is only connected to the 4G module, which is used to transmit the RTCM data returned by the CORS server back to RTK for solution.

[0042] In the present utility model, the model of 4G module U9 is EC800M, and pin 2 of U9 is connected to the reset circuit; pins 3, 5, and 19 of U9 are connected to GND; pin 4 of U9 is connected to the Power_In port, and is also connected to a 0.1uF capacitor C36 and then grounded for power supply filtering; pins 15 and 16 of U9 are respectively connected to pins 6 and 10 of the analog switch chip U10. In addition, the reset circuit includes a transistor Q1, the model of which is S8050, and pin 2 of U9 is connected to the collector of Q1 in the reset circuit, and a resistor R2 is connected between the emitter and base of Q1, one end of the resistor R2 is grounded, and the other end is connected to the resistor R13 and then connected to the 4G-RESET port.

[0043] Furthermore, the power supply circuit includes a lithium battery charging / power supply circuit, a DC-5V circuit, a DC-3.3V circuit, and an ADC circuit, and the lithium battery charging / power supply circuit is connected to the DC-5V circuit, the DC-3.3V circuit, and the ADC circuit.

[0044] like Figure 2 As shown, the lithium battery charging / power supply circuit includes a lithium battery, a power switch, and a charging circuit, wherein the lithium battery is connected to the power switch, the power switch is a self-locking switch, the charging circuit is connected to the lithium battery, and a charging indicator light and a charging interface are provided in the charging circuit, and the charging interface adopts a Type-C interface. Specifically, the lithium battery is a standard voltage 3.7V lithium battery, which is connected through a 2pin battery interface P1. In the utility model, a 3.7V, 2000mAh lithium battery is used; the power switch is a self-locking switch. In the utility model, a 6-pin self-locking switch POWER1 is used, the output pin of the self-locking switch is connected to the system power supply port Power_In, and the 100uF capacitor C7 is connected to GND; the main chip U3 of the charging circuit is TP4056X, pins 1 and 3 of U3 are connected to GND, pin 2 is connected to a 1kΩ resistor to GND, and pin 4 is connected to two parallel 4.7uF capacitors C12 and C15 to GND for filtering. At the same time, a 2kΩ resistor R4 is also connected to pin 2 of the charging indicator LED1, and pin 1 of LED1 is connected to pin 7 of U3, indicating that charging is in progress. At this time, LED1 displays red, and pin 3 of LED1 is connected to pin 6 of U3, indicating that charging is complete. At this time, LED1 displays green. Preferably, the LED1 is a 3-pin red and green two-color common anode LED lamp. In addition, the interface of the charging circuit is a Type-C interface USB1, and the Type-C interface adopts a 7pin interface.

[0045] The above-mentioned DC-5V circuit is a boost circuit. The main chip U2 of the circuit is TPS613222ADBVR. The input end of the DC-5V circuit is connected to the system power supply port Power_In of the lithium battery charging / power supply circuit. The system power supply port Power_In is connected to a 2.2uF capacitor C8 for input filtering. The system power supply port Power_In is also connected to a 4.7uH inductor L1. The other end of L1 is connected to pin 1 of U2. Pin 2 of U2 is connected to GND. Pin 3 and pin 5 of U2 are suspended. Pin 4 of U2 is the output end. The output end is connected to the 5V port as a 5V electrical output end. A Schottky diode D3 is connected between pin 1 and pin 4 of U2. The model of D3 is B340A. A 22uF capacitor C6 is connected between the output 5V port and GND for output filtering.

[0046] The above-mentioned DC-3.3V circuit is a step-down circuit, which steps down the voltage from 5.0V to 3.3V. The main chip U4 of the circuit is TPS76633DR. Pins 5 and 6 of U4 are connected to the 5V port as the input end of the DC-3.3V circuit, and the 10uF capacitor C9 is also connected to GND for input filtering; pins 3 and 4 of U4 are connected to GND; pins 1 and 2 of U4 are suspended; pins 7 and 8 of U4 are the output ends of the DC-3.3V circuit, which are connected to the 3.3V port (i.e., the STM-3.3V port) as the 3.3V power supply output end, and are connected to the 10uF capacitor C13 and the 4.7uF capacitor C14 and then grounded for output filtering.

[0047] The above-mentioned ADC circuit includes a reference source circuit and a voltage division measurement circuit. The reference source circuit is a step-down circuit, which steps down the voltage from 3.3V to 3.0V. The main chip U1 of the circuit is REF3030AIDBZR. Pin 1 of U1 serves as the input end of the reference source circuit, connected to the STM-3.3V port, and connected to 0.1uF capacitor C2 and 1uF capacitor C3 and then grounded for input filtering; Pin 2 of U1 serves as the output end of the reference source circuit, connected to the reference source 3V port (i.e., VREF+3V port), and also connects 1uF capacitor C4 and 0.1uF capacitor C5 to GND for output filtering; Pin 3 of U1 is connected to GND. In addition, the 3.3V port and the lithium battery charging / power supply circuit are respectively connected to the voltage divider measurement circuit, which is used to divide the lithium battery voltage and then output it. The power output end of the voltage divider measurement circuit is connected to the single-chip system circuit. Specifically, the voltage divider measurement circuit includes diodes D1 and D2, 0.1uF capacitor C1, 100KΩ resistors R1 and R2, and its connection method is as follows: Figure 2As shown, diodes D1 and D2 are connected in series and then connected to the STM-3.3V port and GND in reverse; 100KΩ resistors R1 and R2 are connected in series and then connected to Power_In and GND; the midpoint of the series connection of D1 and D2 is connected to the midpoint of the series connection of R1 and R2, and is also connected to the BAT_ADC port; capacitor C1 is connected to the BAT_ADC port and GND for ADC filtering.

[0048] Through the above circuit design, when powered on, the channel control circuit remains normally closed, the 4G module communicates with the MCU minimum system, and connects to the CORS server; after the CORS server is successfully connected, the channel control circuit is opened, the 4G module communicates with the RTK module, the communication protocols are RTCM and NMEA, and the MCU minimum system monitors NMEA communications and parses the positioning data.

[0049] Furthermore, after successfully connecting to the CORS server, the display screen shows the positioning mode (GNSS, DGNSS, RTK_float, RTK-fixed), satellite time, number of satellites (0-12), and longitude and latitude information. In addition, when powered on, the Bluetooth circuit is enabled, and the CORS server IP, user name, account, and password are input through the Bluetooth terminal (mobile phone, tablet, computer and other Bluetooth devices). After successfully connecting to the CORS server, the Bluetooth circuit is disabled, and the server IP, user name, account, and password are saved to the built-in FLASH of the microcontroller minimum system, and automatically connected and working after the power is turned on again.

[0050] Furthermore, after successfully connecting to the CORS server, when the positioning mode is RTK-float or RTK-fixed, short press the custom button to record the current coordinate position, and the screen displays "P1-"; short press the custom button again to record the coordinate position of the second point, the screen displays "P1-P2", and calculate the distance between the two points; short press the custom button again, the screen displays "P1-", and the first point position is re-recorded, and so on.

[0051] Furthermore, when the CORS server connection fails, the display screen displays a connection failure prompt, enables the Bluetooth module, and prompts to re-enter the CORS server IP, user name, account, and password.

[0052] As another implementation method, when powered on, long press the custom button to exit the current CORS server connection and enable the Bluetooth module. You can re-enter the CORS server IP, user name, account, and password to connect.

[0053] The 4G network mobile station base module adapted to the serial port RTK module proposed in the utility model can adapt to the RTK module with a serial port function, configure the 4G network CORS server through Bluetooth, connect to the CORS server base station through the 4G network, and then switch the RTK module communication through the channel control circuit, and use the RTK technology to display the positioning status in real time, thereby realizing a network RTK mobile station function with strong compatibility, flexibility and convenience.

[0054] Although the above describes the specific implementation methods of the utility model in combination with the accompanying drawings, it is not intended to limit the scope of protection of the utility model. Technical personnel in the relevant field should understand that on the basis of the technical solution of the utility model, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the utility model.

Claims

1. A 4G network mobile station base module adapted to the serial port RTK module, It is characterized in that Including single chip system circuit, display circuit, Bluetooth circuit, channel control circuit and 4G communication circuit integrated on the same circuit board; Among them, the single-chip microcomputer system circuit includes a single-chip microcomputer minimum system circuit, the single-chip microcomputer minimum system circuit includes a single-chip microcomputer, the display screen circuit, the Bluetooth circuit, and the channel control circuit are respectively connected to the single-chip microcomputer, the channel control circuit includes an analog switch chip and an RTK base circuit connected to each other, the 4G communication circuit is connected to the analog switch chip, and the RTK base circuit is connected to an external serial port RTK module.

2. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 1, It is characterized in that The single-chip microcomputer system circuit also includes a custom button, an SD memory card circuit and a burning circuit connected to the single-chip microcomputer minimum system circuit; the display screen circuit includes a TFT display screen module and a brightness adjustment circuit connected to each other; the Bluetooth circuit includes a Bluetooth module and a Bluetooth enabling circuit; the 4G communication circuit includes a 4G module and a reset circuit connected to each other.

3. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 2, It is characterized in that The TFT display screen module, the Bluetooth module, the Bluetooth enabling circuit, the analog switch chip, the RTK base circuit and the reset circuit are all connected to the single chip microcomputer.

4. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 2, It is characterized in that The single-chip microcomputer minimum system circuit also includes a crystal oscillator and peripheral circuits connected to the single-chip microcomputer; the custom button is a self-reset button, and the self-reset button is connected to the single-chip microcomputer and GND; the SD memory card circuit includes an SDIO interface chip, and the SDIO interface chip is connected to the single-chip microcomputer; the burning circuit adopts the SW serial debugging mode, including a burning port terminal, and the burning port terminal is connected to the single-chip microcomputer.

5. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 2, It is characterized in that The TFT display screen module adopts a TFT color display screen, and the TFT color display screen adopts an SPI interface; the brightness adjustment circuit is a power supply switching circuit, and the power supply switching circuit includes a switching switch, and the switching switch connects the TFT color display screen, a 5V power supply, and a 3.3V power supply.

6. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 2, It is characterized in that The Bluetooth module supports SPP Bluetooth and BLE Bluetooth protocols, and the Bluetooth enabling circuit is used to control the opening and closing of the Bluetooth module.

7. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 2, It is characterized in that The common port of the analog switch chip is connected to the 4G communication circuit, the normally closed port is connected to the single-chip microcomputer, and the normally open port is connected to the RTK base circuit. The single-chip microcomputer is used to control the switching of the 4G communication circuit and the RTK base circuit.

8. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 1, It is characterized in that It also includes a power supply circuit integrated on the same circuit board; the power supply circuit includes a lithium battery charging / power supply circuit, a DC-5V circuit, a DC-3.3V circuit, and an ADC circuit. The power supply circuit is connected to the single-chip computer system circuit, the display circuit, the Bluetooth circuit, the channel control circuit, and the 4G communication circuit to supply power to each circuit part.

9. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 8, It is characterized in that The lithium battery charging / power supply circuit includes a lithium battery, a power switch, and a charging circuit; the lithium battery charging / power supply circuit is connected to a DC-5V circuit, a DC-3.3V circuit, and an ADC circuit; The lithium battery is connected to a power switch, which is a self-locking switch. The charging circuit is connected to the lithium battery. A charging indicator light and a charging interface are provided in the charging circuit, and the charging interface adopts a Type-C interface.

10. The 4G network mobile station base module adapted to the serial port RTK module as claimed in claim 9, It is characterized in that The DC-5V circuit is a boost circuit, the input end of the DC-5V circuit is connected to the lithium battery charging / power supply circuit, and the output end of the DC-5V circuit is connected to the 5V port as a 5V electrical output end; The DC-3.3V circuit is a step-down circuit, the input end of the DC-3.3V circuit is connected to a 5V port, and the output end of the DC-3.3V circuit is connected to a 3.3V port as a 3.3V power supply output end; The ADC circuit includes a reference source circuit and a voltage divider measurement circuit; the reference source circuit is a step-down circuit, the input end of the reference source circuit is connected to a 3.3V port, and the output end of the reference source circuit is connected to a reference source 3V port; the 3.3V port and the lithium battery charging / power supply circuit are respectively connected to the voltage divider measurement circuit, the voltage divider measurement circuit is used to evenly divide the lithium battery voltage and then output it, and the power supply output end of the voltage divider measurement circuit is connected to the single-chip computer system circuit.

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