Internet of Things development board, Internet of Things development system and error correction method

Abstract

The invention provides an Internet of Things development board, an Internet of Things development system and an error correction method, and the Internet of Things development board is provided with a core board and at least one expansion interface. The core board is detachably connected with a bottom board of the Internet of Things development board, the expansion interfaces are used for being connected with an external expansion module to expand the Internet of Things development board, and all the expansion interfaces are connected with the core board through a bus. Therefore, the use of a bread board, a hole board or the re-drawing of a PCB can be avoided, and a required circuit can be quickly built. Besides, the core board is detachably connected with the bottom board of the Internet of Things development board, so that when a developer needs to use other core boards, the developer does not need to purchase a new development board again and can directly replace the core board, the research and development efficiency is improved, and the research and development cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of Internet of Things, and in particular to an Internet of Things development board, an Internet of Things development system and an error correction method. Background Art

[0002] With the popularity of the Internet of Things and smart devices, the Internet of Things development board is used in the process of traditional Internet of Things devices and hardware development. The Internet of Things development board is an electronic device that integrates processors, memory, storage, and various interfaces and protocols. It provides a platform for developers to easily design and implement various Internet of Things applications.

[0003] However, the current IoT development boards have relatively simple functions. If you want to expand more external devices, you need to use breadboards, perforated boards or redraw PCBs to build or develop them yourself. The entire construction process is lengthy and cumbersome, and requires a lot of time and cost. Summary of the invention

[0004] The embodiments of the present invention provide an Internet of Things development board, an Internet of Things development system and an error correction method to solve the problem that the current Internet of Things development board has a single function.

[0005] In the first aspect, an embodiment of the present invention provides an Internet of Things development board, which is provided with a core board and at least one expansion interface; the core board is detachably connected to the base plate of the Internet of Things development board, and the expansion interface is used to connect the peripheral expansion module to expand the Internet of Things development board, and all expansion interfaces are connected to the core board through a bus.

[0006] In a possible implementation, the core board and the base plate of the Internet of Things development board are connected via a board-to-board connector or via a BGA.

[0007] In a possible implementation, the expansion interface is at least one of a horn socket, a flexible printed circuit board socket, or a row socket.

[0008] In a second aspect, an embodiment of the present invention provides an Internet of Things development system, including the Internet of Things development board, standard device library and schematic library of the first aspect;

[0009] The IoT development board is provided with a core board, multiple independent modules, at least one expansion interface and multiple external interfaces; the core board is detachably connected to the bottom plate of the IoT development board, and the expansion interface is used to connect the peripheral expansion module to expand the IoT development board;

[0010] The standard device library includes a variety of peripheral expansion modules, which include components or core boards. All peripheral expansion modules are packaged based on the preset standard bus connection standard of the IoT development board. Each core board corresponds to a micro control unit.

[0011] The schematic library includes schematics and PCB diagrams of all components and core boards in the standard device library;

[0012] When the IoT development board needs external expansion, select components from the standard device library and connect them to the expansion interface; when the required components do not exist in the standard device library, modify and draw a new schematic or PCB diagram based on the schematic library;

[0013] When the microcontroller unit of the IoT development board needs to be replaced, the core board corresponding to the microcontroller unit to be replaced is selected from the standard device library to replace the original core board on the IoT development system.

[0014] In a possible implementation, the expansion interface includes a first bull socket and a second bull socket, the first bull socket is used to lead out a first bus of the core board, and the second bull socket is used to lead out a second bus of the core board, the first bus and the second bus together constitute all the buses of the core board, and the first bus and the second bus are different; the selection of the pins of the first bull socket and the second bull socket and the general input and output port of the core board is based on bus direct or isolation; the first bull socket and the second bull socket are both provided with 5V power pins and 3.3V power pins that do not interfere with each other.

[0015] In one possible implementation, the expansion interface includes a flexible printed circuit board socket, which is used to lead out all the general input and output ports of the core board. The selection of the pins of the flexible printed circuit board socket and the general input and output ports of the core board is based on bus pass-through or isolation; the flexible printed circuit board socket is provided with a 5V power pin and a 3.3V power pin that do not interfere with each other.

[0016] In one possible implementation, the expansion interface includes at least one double-row socket, which is used to lead out all the general input and output ports of the core board. The selection of the pins of the double-row socket and the general input and output ports of the core board is based on bus direct or isolated selection; the double-row socket is provided with 5V power pins and 3.3V power pins that do not interfere with each other.

[0017] In a possible implementation, the independent module includes a display screen module, a clock chip module, and a gyroscope chip module connected in parallel on the IIC bus;

[0018] The independent modules also include an Ethernet module, a TF card interface module, an SD card interface module and a TFT screen interface module connected in parallel on the SPI bus;

[0019] The independent module also includes an IIS circuit and an antenna module. The IIS circuit includes an audio decoding circuit and an audio encoding circuit. The antenna module is a ceramic antenna or an antenna module led out through a board-to-board connector.

[0020] The independent modules also include a multi-way independent key switch module, a multi-way touch key switch module, a multi-way DIP switch module, a monochrome LED module, a color LED module and a buzzer connected to the general input and output ports;

[0021] External interfaces include USB interface, SIM interface, audio interface, SD interface, TF interface and Ethernet interface;

[0022] The microcontroller unit of the core board is an ESP32 chip, and the core board is equipped with a FreeRTOS operating system.

[0023] In one possible implementation, the IoT development board also includes a jumper cap;

[0024] When the general input and output ports in the IoT development board or the devices in the IoT development board have multi-function multiplexed pins, modify the IoT development board based on jumper caps;

[0025] When the pins of independent modules in the IoT development board need to be modified, they are brought out through the double-row socket;

[0026] When multiple peripheral expansion modules need to use the same pins, a cascade design is performed through the expansion interface.

[0027] In a third aspect, the present invention further provides an error correction method for an Internet of Things development system, the error correction method is applied to the Internet of Things development system of any one of the second aspects, the expansion interface of the Internet of Things development system needs to cascade multiple peripheral expansion modules, and the peripheral expansion module is provided with at least one of a jumper cap, a 0 ohm resistor or a dip switch; the error correction method comprises:

[0028] When the target peripheral expansion module fails to work properly, the error is located based on adjusting the connection order of all peripheral expansion modules on the expansion interface; the target peripheral expansion module is any peripheral expansion module; and / or

[0029] When the target peripheral expansion module fails to work properly, locate the error based on voltage and current testing of the expansion interface; and / or

[0030] When the target peripheral expansion module fails to work properly, the error is located based on code scanning of all peripheral expansion modules;

[0031] After the error is located, the error is corrected by adjusting the jumper cap on the peripheral expansion module; and / or

[0032] After the error is located, the error is corrected by adjusting the DIP switch on the peripheral expansion module; and / or

[0033] After the error is located, the error is corrected by adjusting the 0 ohm resistor on the peripheral expansion module.

[0034] The embodiment of the present invention provides an Internet of Things development board, which not only designs an expansion interface for connecting peripheral expansion modules, thereby avoiding the use of a breadboard, a perforated board or redrawing a PCB board, but also can quickly build the required circuit. In addition, by detachably connecting the core board to the bottom plate of the Internet of Things development board, when the developer needs to use another core board, there is no need to repurchase a new development board, and the core board can be directly replaced, thereby improving R&D efficiency and reducing R&D costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative labor.

[0036] Figure 1 is a block diagram of an Internet of Things development board provided by an embodiment of the present invention;

[0037] Figure 2 is a schematic diagram of the cascading of peripheral expansion modules provided by an embodiment of the present invention;

[0038] Figure 3 It is a structural schematic diagram of an Internet of Things development board provided by an embodiment of the present invention;

[0039] Figure 4 is a circuit diagram of an OLDE12864 display screen module provided by an embodiment of the present invention;

[0040] Figure 5 It is a circuit diagram of the RX8025 clock chip module provided by an embodiment of the present invention;

[0041] Figure 6 is a circuit diagram of the MPU6050 gyroscope chip module provided by an embodiment of the present invention;

[0042] Figure 7 It is a circuit diagram of the interface circuit of the W5500 network card provided by an embodiment of the present invention;

[0043] Figure 8 is a circuit diagram of a network connection of a W5500 network card provided by an embodiment of the present invention;

[0044] Fig. 9 is a circuit diagram of a TF card interface module provided by an embodiment of the present invention;

[0045] Fig.10 is a circuit diagram of an SD card interface module provided by an embodiment of the present invention;

[0046] Fig.11 is a circuit diagram of a 1-way independent key switch provided by an embodiment of the present invention;

[0047] Fig.12 4 is a circuit diagram of a 4-way 3-speed DIP switch provided by an embodiment of the present invention;

[0048] Fig.13 is a circuit diagram of one of the four-way touch key switch modules provided in an embodiment of the present invention;

[0049] Fig.14 is a circuit diagram of a 5V step-down circuit provided in an embodiment of the present invention;

[0050] Fig.15 is a circuit diagram of a 3.3V step-down circuit provided by an embodiment of the present invention;

[0051] Fig.16 An ESP32-based Internet of Things development board is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0053] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0054] As described in the background technology, in the traditional IoT device and hardware development process, engineers will use development boards, and traditional development boards have relatively fixed functions and a relatively single product development direction. If you want to expand more external devices in a traditional development board, engineers need to use breadboards, perforated boards, or redraw PCBs for development. The entire environment construction process is lengthy and cumbersome, which not only requires a lot of cost and time, but also easily leads to various unpredictable problems, causing the R&D cost and R&D cycle to grow exponentially.

[0055] In addition, the inventors found that multiple microcontroller units (MCUs) and multiple peripheral components are also needed during the hardware development process. However, for current development boards, one development board only corresponds to one MCU, so when another MCU is needed, it is also necessary to use or purchase another development board, resulting in a sharp increase in R&D costs.

[0056] In order to solve the problems of the prior art, the embodiments of the present invention provide an Internet of Things development board, an Internet of Things development system and an error correction method. The Internet of Things development board provided by the embodiments of the present invention is first introduced below.

[0057] An Internet of Things development board is provided with a core board and at least one expansion interface. The core board is detachably connected to a bottom plate of the Internet of Things development board, the expansion interface is used to connect a peripheral expansion module to expand the Internet of Things development board, and all expansion interfaces are connected to the core board through a bus.

[0058] In some embodiments, in order to meet the needs of users for different MCUs without the need to purchase a development board separately, the core board and the base plate of the Internet of Things development board are connected by a board to board (BTB) connection seat or by a BGA connection. Exemplary, two BTB wiring seats can be provided for the connection between the core board and the base plate. By making the core board into an independent device, the packaging form can be a BTB or BGA form, so that it can be fixed on the base plate by welding or plugging.

[0059] In this embodiment, the baseboard of the development board is connected to the core board through a BTB connector or BGA interface with a marked line sequence, ensuring the consistency of the expansion circuit and other circuits installed on the baseboard. The core board provides connection with the baseboard through a BTB connector or BGA interface with a standard line sequence.

[0060] Specifically, the core board includes necessary circuits and necessary chips such as MCU, Flash, RAM, crystal oscillator, antenna, etc., and the core board develops pins according to unified standards. In addition, the bus positions and line sequences of IIC, SPI, CAN, I2S, etc. between the MCU core board and the baseboard are kept consistent to ensure the consistency of the device circuit.

[0061] In this embodiment, in traditional hardware development, different circuits and devices are involved, so there are very few standard codes that can be used, which leads to most engineers choosing to repeatedly develop the control code of each circuit and device, and affects the efficiency of research and development. In this embodiment, the microcontroller unit of the core board is an ESP32 chip, and the core board comes with an operating system based on FreeRTOS secondary development, and supports MicroPython language development. There are schematic libraries, PCB libraries, and code libraries for each circuit, and engineers can migrate directly, greatly shortening the development time and cost.

[0062] In some embodiments, the expansion interface is at least one of a header, a flexible printed circuit board socket, or a strip socket.

[0063] In this embodiment, when the expansion interface is a horn seat, the expansion interface includes the first horn seat and the second horn seat, the first horn seat is used to lead to the first bus of the core board, the second horn seat is used to lead to the second bus of the core board, the first bus and the second bus jointly constitute all the buses of the core board, and the first bus and the second bus are different. The selection of the pins of the first horn seat and the second horn seat and the universal input and output port of the core board is based on bus direct or selected in an isolated manner, so as to avoid IO confusion causing imperceptible BUG. The first horn seat and the second horn seat are both provided with 5V power pins, 3.3V power pins and ground pins that do not interfere with each other.

[0064] Bus pass-through means that when using a header for expansion, if the peripheral expansion module is used in a bus connection mode, the bus extends from the input header to the output header. All expansion modules are connected in series using bus pass-through, which can enhance the expansion capability.

[0065] Used isolation means that when using a header for expansion, if a pin of the core board is used in a peripheral expansion module and is used exclusively, the network connection of the pin will be disconnected at the output end of the header to avoid incorrect reuse of subsequent peripheral expansion modules, thereby ensuring the stability of external expansion.

[0066] Exemplarily, the first horn seat A contains 20 pins, and the second horn seat B contains 34 pins. The first horn seat A leads to the first bus of the core board, including IIC-0, SPI-0, CAN-0, I2S bus, and UART0 / 1, and the horn seat provides the connection requirements of commonly used devices. The second horn seat B leads to the second bus of the core board, including IIC-0, SPI-0, CAN-1 and other remaining UART ports. The horn seat is used as a backup solution to connect other uncommon devices or multi-connection device requirements. In addition, the two horns can also be shared, that is, the joint application of all general-purpose input / output ports (General-purpose input / output, GPIO). At this time, some pins will cover the original bus function, which is generally used for device access with more pin multiplexing, such as display devices. For the peripheral expansion module, the right side is the access port of the horn seat, which can be plugged into the IoT development board, and the left side is the access port, and the expansion cascade can also be performed, so as to enhance the research and development capabilities of the development board.

[0067] In this embodiment, when the expansion interface is a flexible printed circuit board socket FPC, the FPC is used to lead out all GPIO pins of the core board. The selection of the pins of the flexible printed circuit board socket and the general input and output port of the core board is based on bus direct or isolation; the flexible printed circuit board socket is provided with a 5V power pin, a 3.3V power pin and a ground pin that do not interfere with each other.

[0068] In this embodiment, FPC is used for the lead-out of special equipment, such as engineering mainboard, equipment mainboard, and also has the function of cascade lead-out. In addition, FPC also has a standard line sequence.

[0069] Similarly, bus pass-through means that when using FPC for expansion, if the peripheral expansion module is used in a bus connection mode, the bus extends from the access FPC to the output FPC. Using bus pass-through to connect all expansion modules in series can enhance the expansion capability.

[0070] The FPC connector includes 3.3V and 5V power pins, GND ground connection pins, and all GPIOs of the core board, including IIC, SPI, CNA, I2S, and all channels of the serial port. In addition, the order and position of the pins in the FPC connector are defined and cannot be changed. However, in different MCU core boards, the pins used by each peripheral may be different.

[0071] Used isolation means that when using FPC for expansion, if a pin of the core board is used in a peripheral expansion module and is used exclusively, the network connection of the pin will be disconnected at the output end of the FPC to avoid incorrect reuse of subsequent peripheral expansion modules, thereby ensuring the stability of external expansion.

[0072] In this embodiment, the expansion interface includes at least one double-row socket, which is used to lead out all the general input and output ports of the core board. The selection of the pins of the double-row socket and the general input and output ports of the core board is based on bus direct or isolation. The double-row socket is provided with a 5V power pin and a 3.3V power pin that do not interfere with each other.

[0073] In order to meet different needs, bull horn sockets, flexible printed circuit board sockets and row sockets can be set up at the same time.

[0074] In some embodiments, the IoT development board also includes commonly used OLED display screens, RX8025 clock chips, MPU6050 gyroscope chips, W5500 Ethernet chips, 4G network card chips, TF / SD card circuits, TFT screen circuits, 4-way independent key switches, 4-way touch switches, 4-way dip switches, monochrome LEDs, color WS2812B, buzzers, audio codec chips and other externally connected independent modules, and has the ability to develop commonly used IoT devices. In addition, the IoT development board also includes multiple external interfaces, such as serial ports of different specifications, 1 USB interface, 1 Ethernet interface, 1 TF card interface, 1 SD card interface, 1 3.5mm audio interface, 1 2P2.54 audio output port, and 1 SIM card interface.

[0075] In order to facilitate the use of the Internet of Things development board for design, the Internet of Things development board provided by the present invention not only designs an expansion interface that can be used to connect peripheral expansion modules, thereby avoiding the use of a breadboard, a perforated board or redrawing a PCB board, but can quickly build the required circuit. In addition, by detachably connecting the core board to the bottom plate of the Internet of Things development board, when the developer needs to use another core board, there is no need to repurchase a new development board, and the core board can be directly replaced, thereby improving the efficiency of research and development and reducing research and development costs.

[0076] In a second aspect, the present invention further provides an Internet of Things development system, comprising the Internet of Things development board, standard device library and schematic library provided in the first aspect.

[0077] like Figure 1 As shown, the IoT development board is provided with a core board, multiple independent modules, at least one expansion interface and multiple external interfaces. The core board is detachably connected to the bottom plate of the IoT development board, and the expansion interface is used to connect the peripheral expansion module to expand the IoT development board.

[0078] The standard device library includes a variety of peripheral expansion modules, which include components or core boards. All peripheral expansion modules are packaged based on the preset standard bus connection standard of the IoT development board, and each core board corresponds to a microcontroller unit. By setting up a standard device library, designers can directly use the peripheral expansion modules in the standard device library for external expansion without having to look for other devices for design. In addition, since all peripheral expansion modules are packaged based on the preset standard bus connection standard of the IoT development board, they can be used directly without considering issues such as interfaces, which can save development time and avoid connection errors caused by inconsistent interface standards.

[0079] The schematic library includes schematics and PCB diagrams of all components and core boards in the standard device library. When the standard device library does not have the peripheral expansion module required by the designer, the designer does not need to redraw the schematic or PCB diagram, and can directly use the schematic and PCB diagram in the schematic library, greatly shortening the R&D time and cost.

[0080] When the IoT development board needs external expansion, select components from the standard device library and connect them to the expansion interface. When the required components do not exist in the standard device library, modify and draw a new schematic or PCB diagram based on the schematic library.

[0081] When the microcontroller unit of the IoT development board needs to be replaced, the core board corresponding to the microcontroller unit to be replaced is selected from the standard device library to replace the original core board on the IoT development system.

[0082] The expansion interface is a bull horn socket, a flexible printed circuit board socket or a socket strip, which will not be described in detail here. Please refer to the relevant introduction of the bull horn socket, the flexible printed circuit board socket or the socket strip in the first aspect.

[0083] In addition, in order to facilitate subsequent testing and error location, voltage and current test pins are also set on the expansion interface to facilitate subsequent error correction. Voltage and current test pins can be set on the horn socket, flexible printed circuit board socket or strip socket.

[0084] The development board and peripheral expansion module in the present invention adopt standardized interface rules. During the development process, the designer does not need to redesign the PCB board or the components that need to be expanded and used, and can directly select components from the standard component library. In addition, the peripheral expansion module can also be used in cascade. For the pins of GPIO or device multi-function reuse, the development board can be modified by using jumper caps, and cascading can be achieved without using any welding equipment.

[0085] In addition, for bus-type peripheral expansion modules, in order to prevent pin misalignment, a standard interface cascade design can be used, that is, a cascade design can be performed with a header, a flexible printed circuit board socket, or a strip socket.

[0086] There are two types of peripheral expansion modules, one with only an input port but no output port, and the other with both an input port and an output port. For peripheral expansion modules with only an input port, there is no need to consider the external expansion connection task, only the line sequence of the input port needs to be ensured. For peripheral expansion modules with both an input port and an output port, they can be cascaded for expansion when in use. When cascading, if it is a bus pin, it is directly led out to the next level peripheral expansion module through the lead-out pin, such as Figure 2 However, if the peripheral expansion module has already occupied the GPIO, in order to avoid pin multiplexing, the peripheral expansion module will not be brought out.

[0087] For easier understanding, see Figure 3 IoT development board in Figure 3 The black part in the figure is the core board of the replaceable MCU, the gray grid is the bus, the gray blocks are the external interfaces, and the white blocks are the independent modules or chips on the baseboard. Figure 3 The expansion interfaces include double bull-horn socket expansion interface, double-row socket expansion interface and FPC expansion interface.

[0088] In some embodiments, Figure 3 As shown, the independent modules include a display screen module, a clock chip module and a gyroscope chip module connected in parallel on the IIC bus.

[0089] In this embodiment, the OLDE12864 display screen module on the IIC bus is used as a display device during the development process, and can also be used to display device information in the development project. The RX8025 clock chip module is used as a device during the development process, and is also used as a clock calibration device for the development board. The MPU6050 gyroscope chip module is used as a device during the development process.

[0090] In this embodiment, if Figure 4 The figure shows the circuit principle diagram of the OLDE12864 display module, which consists of a driver chip, a control circuit and a power supply. The display principle is to control the light-emitting state of each pixel by current. The driver chip receives instructions from the microcontroller of the core board, transmits data through the I2C interface, and controls the switch of the pixel to display the required graphics and text. Each pixel is composed of organic light-emitting materials and emits light after power is turned on, thereby realizing high-contrast and wide-viewing-angle image display.

[0091] In this embodiment, Figure 5This is the schematic diagram of the RX8025 clock chip module. The RX8025 is an integrated real-time clock (RTC) chip that contains an oscillator, timer, alarm, and other control circuits. An internal crystal oscillator is used to provide a stable clock signal. The RX8025 counts the clock signal through an internal counter and updates the time data according to the set time base (such as increasing once per second).

[0092] In this embodiment, Figure 6 This is the schematic diagram of the MPU6050 gyroscope chip module. The MPU6050 gyroscope chip is used to monitor the acceleration and angular velocity of an object and perform attitude detection. The working principle is that the sensor component includes a three-axis accelerometer for measuring the linear acceleration of an object in the three directions of X, Y, and Z, and a three-axis gyroscope for measuring the angular velocity of an object around the X, Y, and Z axes. The analog signal is converted into a digital signal through the internal ADC (analog-to-digital converter) for data processing. It communicates with the main control chip (such as a microcontroller) through the I2C interface to transmit acceleration and gyroscope data. The built-in digital motion processing unit (DMP) can perform sensor data fusion to provide more accurate attitude and motion status.

[0093] In some embodiments, Figure 3 As shown, the independent modules include an Ethernet module, a TF card interface module, an SD card interface module and a TFT screen interface module connected in parallel on the SPI bus.

[0094] In this embodiment, the Ethernet module is Figure 3 The W5500 network card in the system consists of a W5500 chip, an Ethernet interface, and related circuits. It is used as a device during the development process, and can also be used as a network card for the development board to connect to the network. The peripheral circuit principles of W5500 include power management, SPI interface connection, reset circuit, and external crystal oscillator circuit. The power management part usually provides a 3.3V power supply to ensure the normal operation of the chip. Figure 7-8 As shown, the SPI interface is used to communicate with the main control chip, including MOSI, MISO, SCK and CS signal lines. The reset circuit ensures that the chip can be reset when powered on through a button or circuit. The external crystal oscillator circuit provides a clock signal to ensure stable data transmission. In addition, W5500 realizes network connection through an RJ45 interface with a network transformer. The transformer is used for isolation and signal matching to enhance the stability and reliability of the network signal. These peripheral circuits jointly support the functions of W5500 and ensure its reliable connection to the network.

[0095] In this embodiment, if Fig. 9The TF card interface module shown in the figure mainly includes data storage, control signals and power management. The data exchange between the master control and the TF card is realized through the 4-wire method of SPI communication, including SCK (clock), MOSI (master output slave input), MISO (master input slave output) and CS (chip select). The master control reads or writes data by sending commands, and the TF card stores the data in the internal flash memory. Power management usually provides 3.3V power supply to ensure the normal operation of the card. The entire circuit design needs to pay attention to signal integrity and power stability to ensure the reliability of data transmission.

[0096] In this embodiment, if Fig.10 The SD card interface module shown in the figure mainly includes data storage, control signals and power management. Through SDMMC communication, data is transmitted through multiple signal lines, usually including command lines, clock lines and data lines. The master reads or writes data by sending commands, and the SD card stores the data in the internal flash memory. The power management part usually provides 3.3V power supply to ensure the normal operation of the card. The entire circuit design needs to pay attention to signal integrity and power stability to ensure the reliability and efficiency of data transmission.

[0097] In some embodiments, Figure 3 As shown, the independent module also includes an IIS circuit, an antenna module, and a multi-way independent key switch module connected to the general input and output port, a multi-way touch key switch module, a multi-way dip switch module, a monochrome LED module, a color LED module, a buzzer, and a serial port device.

[0098] In this embodiment, the IIS circuit includes an audio decoding circuit and an audio encoding circuit, and leads to a 3.5mm microphone interface and a 2P2.54 specification speaker interface, and also includes a set of power amplifier circuits, which are used as equipment in audio development. In this application, the ES8311 audio circuit is used in combination with the NS4150. The ES8311 is a high-performance audio decoding chip, which is mainly used for the conversion and processing of audio signals and includes analog and digital circuits. The analog part receives and amplifies the audio signal, and the digital part is responsible for decoding the audio data, supports I2S and PCM interfaces, and communicates with the main control. NS4150 is an efficient audio power amplifier chip that uses Class D amplification technology and can efficiently amplify the audio signal to the speaker. Its circuit principle includes modulation, amplification and output of the input audio signal, and has the characteristics of high efficiency and low distortion. The combination of the two can achieve high-quality audio playback and is suitable for various audio devices.

[0099] In this embodiment, the present application uses a 4-way independent button switch, the positive pole of the button is connected to GPIO, and the negative pole is connected to GND. It can be triggered by interrupt or scan mode and used as a scan button or interrupt button during the development process. Fig.11 The circuit diagram of one of the independent key switches is provided. When the key is not pressed, the pull-up resistor pulls the microcontroller input pin high, and the input pin voltage is Vcc. When the key is pressed, one end of the key is connected to the ground, causing the input pin voltage to drop to 0V instantly.

[0100] In this embodiment, if Fig.12 As shown, this application uses a 4-way 3-position dip switch. The switch access end is connected to the GPIO, and the middle position is the short-circuit position. When the switch is in the middle position, it does not affect other operations of the GPIO. The upper position is connected to the 3.3V power supply, and when it is in the upper position, the GPIO can be detected as a high level. The lower position is connected to GND, and when it is in the lower position, the GPIO can be detected as a low level. The dip switch can be used for startup status detection during the development process.

[0101] In this embodiment, if Fig.13 As shown, this application uses a 4-way touch button switch module. Fig.13 T0 in the figure is the touch pad. The ESP32 touch sensor works using capacitive touch technology. The ESP32 built-in touch sensor detects touch by measuring changes in capacitance. When a finger approaches the sensor, it affects the surrounding electric field, causing the capacitance value to change. The ESP32 reads the capacitance value change through an analog-to-digital converter and converts it into a digital signal to determine whether a touch has occurred.

[0102] In this embodiment, a passive buzzer is also included. The device includes a buzzer and a control circuit. The control circuit includes a triode. The base of the triode is connected to GPIO. The buzzer is controlled by PWM. The device is used for device control during the development process. A blue LED is also included. The positive pole of the device is connected to VCC and the negative pole is connected to GPIO to form a cathode control circuit. The device is used for device control during the development process. A color LED is also included. The device is a WS2812B model LED, which is controlled by GPIO single line and used as a control device during the development process. The blue LED, color LED, IIS power amplifier circuit, and passive buzzer circuit above are all controlled by GPIO9 and can be controlled and selected by jumper caps. The jumper cap is a four-item jumper cap connected to GPIO9. At the same time, only one way is available. When the jumper cap is on the upper side, GPIO9 is used to control the LED. When on the left side, GPIO9 is used to control the color LED of WS2812. When on the lower side, GPIO9 I2S power amplifier is enabled. When on the right side, use GPIO9 to control the buzzer.

[0103] In some embodiments, the MCU chip adopts the ESP32 series chip, which is fixed to the base plate through the BTB connection method, or is welded to the base plate through the BGA package. For the antenna module, it can be a ceramic antenna, which is fixed to the core board by welding. It is also possible to use four specifications of antenna bases, IPX1, IPX2, IPX3, and IPX4, to fix the antenna base on the core board by welding, and the antenna base can lead out antennas of different specifications by external means. It is also possible to use a wireless antenna, which is led out to the base plate by BTB.

[0104] In addition, the present invention also provides two different step-down circuits. Fig.14 Step down DC12 / 24V to DC5V as the system 5V power supply. TPS5430 uses a switch mode power supply to control the transfer of energy through an internal MOSFET switch. The switch opens and closes at a certain frequency to adjust the output voltage. Feedback control: TPS5430 has a feedback loop to monitor the output voltage in real time and compare it with the reference voltage. By adjusting the duty cycle of the switch, that is, the ratio of the on time to the cycle, a stable output voltage is achieved. Inductor and output capacitor: The inductor and output capacitor together form a low-pass filter to smooth the output voltage and reduce ripple. Fig.15 To step down DC5V to DC3.3V as the system 3.3V power supply. SY8088AAC has a built-in power switch, usually a MOSFET, which is periodically turned on and off under the control signal to adjust the output voltage. Y8088AAC is equipped with a feedback loop to monitor the output voltage in real time and compare it with the internal reference voltage. By adjusting the duty cycle of the switch, a stable output voltage is maintained.

[0105] In some embodiments, the Internet of Things development board is also provided with a variety of external interfaces, such as a USB interface, a SIM interface, an audio interface, an SD interface, a TF interface, an Ethernet interface and a serial port.

[0106] In this embodiment, the UART0 interface is used for firmware burning and debugging log input, and is used in the REPL dialog window in the MicroPython development environment. The UART1 circuit contains a MAX level conversion chip that can output the MAX232 protocol for device-to-device connection. The UART2 circuit directly leads to the serial port for PCB-to-PCB connection. In UART2, a 4G network card module is also connected for use as a device during the development process, and can also be used as a network card for network connection of the development board.

[0107] The Internet of Things development system provided by the present invention, by the core board of the Internet of Things development board and the base plate being detachably connected, can make the designer only need to replace the core board when other types of micro-control units are needed, without having to replace the entire Internet of Things development board. By arranging at least one expansion interface on the Internet of Things development board, when the designer needs to carry out external expansion, the peripheral expansion module can be directly connected through the expansion port, without having to complete the expansion by building a perforated board, a breadboard or a PCB board. In addition, when carrying out external expansion, in order to further facilitate expansion, commonly used components and core boards are all prepared into a standard device library by corresponding packaging, and when expansion is needed, it is directly selected in the standard device library, and further research and development efficiency is improved. In addition, a schematic library is also provided, so that the designer can modify the existing schematic or PCB diagram in the schematic library when finding that there is no suitable device in the standard device library, so as to avoid wasting time by repeated drawing, and the error probability when drawing can also be reduced, and development time is further saved.

[0108] like Fig.16As shown, an ESP32-based IoT development board provided by the present invention, wherein the core board 10 is a MooPi-ES core board, which is connected to the bottom board through a BTB and can be replaced when another MCU needs to be replaced. The 12V-24V external power supply DC socket 12 is controlled by a self-locking power switch 11 to convert the access voltage to 5V or 3.3V. The RJ-45 network interface 13 is an interface of the W5500 driver chip, and the access pin is SPI2. The USB interface 14 can provide a USB-OTG, and the pins are USB-DN: GPIO19, USB-DP: GPIO20. FPC15, large horn socket 34, small horn socket 35, and row socket 30 are all expansion interfaces for external peripheral expansion modules. The large horn socket 34 leads out, and together with the small horn socket 35, all pins in the chip are led out, which is usually used to expand the access of the learning board. The UART2 interface 16 is directly led out by the chip, without level conversion, and the pins are TX=GPIO45, RX=GPIO46. UART1 interface 17 This interface is led out from the chip and converted to a level through RS-232. It can be directly connected to the host computer through a serial port line. The pins are TX=GPIO38 and RX=GPIO39. The OLED12832 display screen 18 is mounted on I2C1, and the ML307A4G core module 19 is mounted on UART2. The module can be enabled or disabled through the POWER pin. The ML307A4G core module 19 is mounted on UART2. The module can be enabled or disabled through the POWER pin. The 4G network connection and power supply indicator 20 is used to display the power supply and network connection status. The ML307A serial port debugging pin 21 can output the debugging information of the module, G=GND, T=TX, R=RX. The ML307A IPX antenna base 22 can be connected to an external antenna, and the 4G SIM card slot 23 is used to install the SIM. The passive buzzer 24 is connected to GPIO9 through four jumper caps. Only one of the four jumper caps 38 is available at the same time. When on the upper side, GPIO9 is used to control the LED, when on the left side, GPIO9 is used to control the WS2812, when on the lower side, GPIO9 is used to enable the I2S amplifier, and when on the right side, GPIO9 is used to control the buzzer. The MPU6050 six-axis gyroscope chip 25 is hung on I2C1. The control pins of the four groups of touch buttons 26 are GPIO11~14 in sequence. Capacitors are added to this group of pins. Try not to use them for other functions. If multiplexing is required, the capacitor on the left side of touch button 0 needs to be manually removed, but this is not recommended. The four-way three-way selection switch 27 is used for level detection. The middle is open, the upper side is connected to power, and the lower side is grounded. The output pins are GPIO47, GPIO48, GPIO43, and GPIO44 in sequence. The control pins of the four independent buttons 28 are GPIO0~3 in sequence. The reset button 29 can be used to reset the development board. The 3.5mm audio interface 30 has not been through the amplifier and can be connected to a microphone and headphones.The I2S speaker external interface 31 can be connected to the external speaker after passing through the power amplifier. The back of the TF card jack 32 is the SD card slot. UART033 is transferred out through CP2102 for MicroPython REPL environment debugging or serial port burning. The RX8025 clock chip 36 and the battery can run independently after the development board is powered off. The jumper cap 37 is from top to bottom: AUDIO: I2S function switch, audio acquisition function on the left, audio output function on the right; RX8025 interrupt pin: the right side is connected to GPIO17, the left side is disconnected; 4G module power: used to control the 4G module power, the right side is connected, the left side is disconnected, and UART2 is occupied after connection; MPU6050 interrupt: the right side is connected to GPIO18, and the left side is disconnected. The indicator light 39 has a WS2812 color indicator on the upper side and a monochrome LED on the lower side, which is connected to GPIO9 through the 28th jumper for control. The TFT screen leads out 41 display part using SPI3, CS=GPIO10, DC=GPIO45, RES=GPIO46, BUSY=GPIO0, and touch is led out through I2C2, RES=GPIO1, INT=GPIO2, BL=GPIO3.

[0109] In the third aspect, the present invention also provides an error correction method for an Internet of Things development system, which is applied to the Internet of Things development system of the second aspect. Multiple peripheral expansion modules need to be cascaded on the expansion interface of the Internet of Things development system, and the multiple peripheral expansion modules are provided with at least one of a jumper cap, a 0 ohm resistor or a dip switch.

[0110] When the target peripheral expansion module fails to work properly, the error is located by adjusting the connection order of all peripheral expansion modules on the expansion interface; the target peripheral expansion module is any peripheral expansion module. And / or

[0111] When the target peripheral expansion module fails to work properly, the error is located based on the voltage and current test of the expansion interface. And / or

[0112] When the target peripheral expansion module fails to work properly, the error is located based on code scanning of all peripheral expansion modules.

[0113] After the error is located, the error is corrected by adjusting the jumper cap on the peripheral expansion module; and / or

[0114] After the error is located, the error is corrected by adjusting the DIP switch on the peripheral expansion module; and / or

[0115] After the error is located, the error is corrected by adjusting the 0 ohm resistor on the peripheral expansion module.

[0116] Specifically, the present invention performs cascade expansion by adopting an expansion interface. When the target peripheral expansion board fails to work properly, the bullnose socket or flexible printed circuit board socket facilitates the removal of peripheral expansion modules one by one to troubleshoot errors and quickly locate the errors.

[0117] In addition, if the error cannot be located by removing them one by one, the power supply voltage qualification test can be performed through the voltage and current test pins reserved on the expansion interface to locate the error. Of course, it is also possible to remove them and perform voltage and current tests on the expansion interface to locate the error.

[0118] In addition, you can also use the Internet of Things development system to scan the codes of each peripheral expansion module, so that the code can feedback the connection status, power supply status, and protocol status of the peripheral expansion module, and the error can be located through the feedback data. Of course, you can also combine these three methods to achieve error location.

[0119] After the error is located, it is necessary to correct the error. The specific correction method is:

[0120] After the error is located, the error is corrected by adjusting the jumper cap on the peripheral expansion module and adjusting the operation pins of the peripheral expansion module on the IoT development board. And / or

[0121] After locating the error, the error is corrected by adjusting the DIP switch on the peripheral expansion module to turn on or off the working status of some functions in the peripheral expansion module. And / or

[0122] After the error is located, the error is corrected by adjusting the 0 ohm resistor on the peripheral expansion module, adjusting the working state of the device in the peripheral expansion module, or modifying the pin sequence used in the peripheral expansion module.

[0123] The present invention can quickly locate the circuit where the error occurs through the above error locating method, and then after locating the error, the error can be quickly corrected through the jumper cap, dip switch and 0Ω resistor on the peripheral expansion module, saving error checking time.

[0124] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0125] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. An Internet of Things development board, characterized in that: The Internet of Things development board is provided with a core board and at least one expansion interface; the core board is detachably connected to the bottom plate of the Internet of Things development board, the expansion interface is used to connect the peripheral expansion module to expand the Internet of Things development board, and all expansion interfaces are connected to the core board through a bus.

2. The Internet of Things development board as claimed in claim 1, characterized in that: The core board and the bottom plate of the Internet of Things development board are connected via a board-to-board connector or via a BGA.

3. The Internet of Things development board as claimed in claim 1 or 2, characterized in that: The expansion interface is at least one of a bull horn socket, a flexible printed circuit board socket or a row socket.

4. An Internet of Things development system, characterized in that: The invention comprises the Internet of Things development board, the standard device library and the schematic library as described in any one of claims 1 to 3; The Internet of Things development board is provided with a core board, multiple independent modules, at least one expansion interface and multiple external interfaces; the core board is detachably connected to the bottom plate of the Internet of Things development board, and the expansion interface is used to connect the peripheral expansion module to expand the Internet of Things development board; The standard device library includes a variety of peripheral expansion modules, which include components or core boards. All peripheral expansion modules are packaged based on the preset standard bus connection standard of the Internet of Things development board, and each core board corresponds to a micro control unit; The schematic library includes schematic diagrams and PCB diagrams of all components and core boards in the standard device library; When the Internet of Things development board needs to be externally expanded, components are selected from the standard device library and connected to the expansion interface; when the required components do not exist in the standard device library, a new schematic or PCB diagram is modified based on the schematic library; When the microcontroller unit of the Internet of Things development board needs to be replaced, a core board corresponding to the microcontroller unit to be replaced is selected from the standard device library to replace the original core board on the Internet of Things development system.

5. The Internet of Things development system as claimed in claim 4, characterized in that: The expansion interface includes a first bullhorn socket and a second bullhorn socket, the first bullhorn socket is used to lead out a first bus of the core board, and the second bullhorn socket is used to lead out a second bus of the core board, the first bus and the second bus together constitute all the buses of the core board, and the first bus and the second bus are different; the selection of the pins of the first bullhorn socket and the second bullhorn socket and the general input and output port of the core board is based on bus direct or isolation; the first bullhorn socket and the second bullhorn socket are both provided with a 5V power pin and a 3.3V power pin that do not interfere with each other.

6. The Internet of Things development system as claimed in claim 4, characterized in that: The expansion interface includes a flexible printed circuit board socket, which is used to lead out all the general input and output ports of the core board. The selection of the pins of the flexible printed circuit board socket and the general input and output ports of the core board is based on bus direct or isolated selection; the flexible printed circuit board socket is provided with a 5V power pin and a 3.3V power pin that do not interfere with each other.

7. The Internet of Things development system as claimed in claim 4, characterized in that: The expansion interface includes at least one double-row seat, which is used to lead out all the general input and output ports of the core board. The selection of the pins of the double-row seat and the general input and output ports of the core board is based on bus direct or isolated selection; the double-row seat is provided with 5V power pins and 3.3V power pins that do not interfere with each other.

8. The Internet of Things development system according to any one of claims 4 to 7, characterized in that: The independent modules include a display screen module, a clock chip module and a gyroscope chip module connected in parallel on the IIC bus; The independent module also includes an Ethernet module, a TF card interface module, an SD card interface module and a TFT screen interface module connected in parallel on the SPI bus; The independent module further includes an IIS circuit and an antenna module, wherein the IIS circuit includes an audio decoding circuit and an audio encoding circuit; the antenna module is a ceramic antenna or an antenna module led out through a board-to-board connector; The independent module also includes a multi-way independent key switch module, a multi-way touch key switch module, a multi-way DIP switch module, a monochrome LED module, a color LED module and a buzzer connected to the general input and output port; The external interfaces include a USB interface, a SIM interface, an audio interface, an SD interface, a TF interface and an Ethernet interface; The microcontroller unit of the core board is an ESP32 chip, and the core board is provided with a FreeRTOS operating system.

9. The Internet of Things development system as claimed in claim 7, characterized in that: The Internet of Things development board also includes a jumper cap; When there are multi-function multiplexed pins on the general input / output ports in the Internet of Things development board or on the devices in the Internet of Things development board, modify the Internet of Things development board based on the jumper cap; When the pins of the independent module in the Internet of Things development board need to be modified, they are led out through the double-row socket; When multiple peripheral expansion modules need to use the same pins, a cascade design is performed through the expansion interface.

10. An error correction method for an Internet of Things development system, characterized in that: The error correction method is applied to the Internet of Things development system according to any one of claims 4 to 9, wherein the expansion interface of the Internet of Things development system is used to cascade multiple peripheral expansion modules, and the peripheral expansion module is provided with at least one of a jumper cap, a 0 ohm resistor or a dip switch; the error correction method comprises: When the target peripheral expansion module fails to work properly, the error is located based on adjusting the connection order of all peripheral expansion modules on the expansion interface; the target peripheral expansion module is any peripheral expansion module; and / or When the target peripheral expansion module fails to work properly, locating the error based on voltage and current testing of the expansion interface; and / or When the target peripheral expansion module fails to work properly, the error is located based on code scanning of all peripheral expansion modules; After the error is located, the error is corrected by adjusting the jumper cap on the peripheral expansion module; and / or After the error is located, the error is corrected by adjusting the DIP switch on the peripheral expansion module; and / or After the error is located, the error is corrected by adjusting the 0 ohm resistor on the peripheral expansion module.

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