阅读说明：本技术 一种基于51单片机插针插孔结合的综合能力实训平台 (Comprehensive capability training platform based on 51-single-chip microcomputer pin and jack combination ) 是由 肖艳军 温博 孟召宗 于 2019-09-06 设计创作，主要内容包括：本发明公开了一种基于51单片机插针插孔结合的综合能力实训平台,包括印刷电路板PCB和面包板模块；所述印刷电路板PCB上设置有单片机最小系统、选择下载电路及USB供电电路、超声波传感器模块、霍尔传感器模块和热电阻温度传感器等。采用插针与插孔相结合的方式,有利于连接的稳固,减小接触不良的可能。将STC51和AT51单片机的下载电路集成于选择下载电路及USB供电电路,减少占用区域,下载电路的切换更为方便快捷。增加了三种传感器模块,扩展了实验项目。外围芯片的管脚全部引出,使用者可自主连接所需的器件,实现了平台的实践价值。增加了面包板模块,可以通过面包板模块自行扩展所需功能组件。(the invention discloses a comprehensive capability training platform based on 51-singlechip pin and jack combination, which comprises a Printed Circuit Board (PCB) and a wrapper sheet module; the PCB is provided with a singlechip minimum system, a selective download circuit, a USB power supply circuit, an ultrasonic sensor module, a Hall sensor module, a thermal resistance temperature sensor and the like. The mode of combining the contact pin and the jack is adopted, so that the connection stability is facilitated, and the possibility of poor contact is reduced. The download circuit of the STC51 and the AT51 single chip microcomputer is integrated in the selective download circuit and the USB power supply circuit, so that the occupied area is reduced, and the download circuit is more convenient and faster to switch. Three sensor modules are added, and the experimental project is expanded. Pins of the peripheral chip are all led out, and a user can independently connect required devices, so that the practical value of the platform is realized. The bread board module is added, and the required functional components can be automatically expanded through the bread board module.)

1. a comprehensive capability training platform based on 51-singlechip pin jack combination is characterized by comprising a Printed Circuit Board (PCB) and a wrapper sheet module; a core circuit and a peripheral circuit are arranged on the printed circuit board PCB; the peripheral circuit controls and realizes corresponding functions through the core circuit; the core circuit comprises a singlechip minimum system, a selective downloading circuit and a USB power supply circuit; the peripheral circuit comprises independent keys, a communication module, a temperature sensor module, a serial-to-parallel module, a transistor array, a parallel-to-serial module, a Darlington transistor, an eight-input NAND gate, an eight-bit buffer, an eight-input trigger, a four-way photoelectric coupler, a display module, an ultrasonic sensor module, a thermal resistance temperature sensor module, a keyboard module, a 3-8 decoder, a 595 latch, a 4-16 decoder, a light emitting diode module, an operational amplifier module, a pull-up resistor module, a switching interface module, an OR gate module, a clock circuit, a dial switch module, a frequency divider module, an I/O expansion module, a relay module, a Hall sensor module, a buzzer module, a three-color lamp module, a four-bit common-cathode common-anode digital tube, a dot matrix module, a precision adjustable resistor, a 573 latch, a DAC conversion module, a 373 latch, a latch, ADC conversion module, resistance module and serial port module.

2. the 51-singlechip pin and jack combination-based comprehensive capacity practical training platform as claimed in claim 1, wherein the singlechip minimum system comprises an STC 51-series singlechip, an AT 51-series singlechip, a crystal oscillator circuit, a reset circuit and a pin and a jack led out from each interface of the singlechip.

3. the 51-singlechip pin and jack combination-based comprehensive capability practical training platform as claimed in claim 2, wherein the selective download circuit and the USB power supply circuit comprise a USB power supply circuit, an STC series 51-singlechip USB program download circuit and an AT series 51-singlechip USBASP program download circuit, and are used for power supply and program download of the whole platform; the USB power supply circuit is simultaneously connected with the STC series 51 single-chip microcomputer USB program downloading circuit and the AT series 51 single-chip microcomputer USBASP program downloading circuit, the USB power supply circuit is connected with the jumper cap, and the corresponding downloading circuit of the single-chip microcomputer is selected by changing the access position of the jumper cap; the STC series 51 single chip microcomputer is connected with an STC series 51 single chip microcomputer USB program downloading circuit, and the AT series 51 single chip microcomputer is connected with an AT series 51 single chip microcomputer USBASP program downloading circuit.

4. the comprehensive ability training platform based on 51-singlechip pin and jack combination as claimed in claim 3, wherein the USB power supply circuit comprises: the GND end of the USB interface is connected with GND; pin 1 of the capacitor J2C1 and pin 1 of the electrolytic capacitor J2C2 are connected with a VCC end of the USB interface, and pin 2 of the capacitor J2C1 and pin 2 of the electrolytic capacitor J2C2 are both connected with GND; pin 1 of fuse F1 is connected to pin 1 of electrolytic capacitor J2C2, pin 2 of fuse F1 is connected to pin 1 of switch SW, and pin 2 of switch SW is connected to pin 1 of resistor J2R 1; pin 2 of the resistor J2R1 is connected to the anode of the LED1, and the cathode of the LED1 is grounded; pin 2 of the switch SW is used as VCC and connected with pin 2 of the three-position wiring terminal J2, and pin 1 and pin 3 of the three-position wiring terminal J2 are respectively used as power supplies of an AT series 51 single chip microcomputer and an STC series 51 single chip microcomputer and are respectively marked as VCC _ AT and VCC _ STC; the VCC _ AT is terminated with a pin 1 of the resistor J2R2, and then is connected with the anode of the LED2 through a pin 2 of the J2R2, and the cathode of the LED2 is grounded; VCC _ STC is terminated with pin 1 of resistor J2R3, and then is connected with the anode of LED3 through pin 2 of J2R3, and the cathode of LED3 is grounded; the VCC _ AT end and the pin 2 of the three-position wiring terminal J2 are respectively connected through a jumper cap, so that power supply for the USBASP program downloading circuit of the AT series 51 single-chip microcomputer is realized; and the jumper cap is respectively connected with a pin 2 of the three-position wiring terminal J2 and a VCC _ STC terminal, so that the USB program downloading circuit of the STC series 51 single-chip microcomputer is powered.

5. the comprehensive capability training platform based on 51-single-chip microcomputer pin jack combination according to claim 4, wherein the STC series 51-single-chip microcomputer USB program downloading circuit comprises: pin 1 of the electrolytic capacitor STCC3, pin 1 of the capacitor STCC4 and a VCC pin of the CH340 chip are connected with a VCC _ STC end of a three-position wiring terminal J2 of the USB power supply circuit; pin 2 of the electrolytic capacitor STCC3, pin 2 of the capacitor STCC4, pin 2 of the capacitor STCC5 and a GND pin of the CH340 chip are all connected with GND; pin 1 of the capacitor STCC5 is connected with pin V3 of the CH340 chip; the D-end of the USB interface of the USB power supply circuit is connected with the VD-pin of the CH340 chip, the D + end of the USB interface of the USB power supply circuit is connected with the VD + pin of the CH340 chip, the X0 and X1 pins of the CH340 chip are respectively connected with the pin 1 and the pin 2 of the crystal oscillator Y1, the pin 1 of the crystal oscillator Y1 is connected with the pin 2 of the capacitor STCC7, the pin 2 of the crystal oscillator Y1 is connected with the pin 1 of the capacitor STCC6, and the pin 2 of the STCC6 is connected with the pin 1 of the STCC7 and is grounded; a TXD pin of the CH340 chip is connected with the cathode of a Schottky diode CH340D3, and the anode of the Schottky diode CH340D3 is connected with an RXD pin of an STC series 51 single chip microcomputer; the RXD pin of the CH340 chip is connected with the pin 1 of the resistor STCR4, and the pin 2 of the resistor STCR4 is connected with the TXD pin of the STC series 51 single chip microcomputer.

6. the comprehensive capacity training platform based on 51-single-chip microcomputer pin and jack combination as claimed in claim 4, wherein the circuit of the AT series 51-single-chip microcomputer USBASP program downloading circuit comprises: the D-of USB interface of the USB power supply circuit connects the negative pole of the switching diode ATD1, pin 1 of resistor ATR5 and pin 1 of resistor ATR6, the positive pole of the switching diode ATD1 is grounded, pin 2 of resistor ATR5 connects VCC _ AT end of three-position connecting terminal J2 of the USB power supply circuit, pin 2 of resistor ATR6 connects PB0 pin of ATMEGA8A chip; the D + of the USB interface of the USB power supply circuit is connected with the cathode of a switch diode ATD2 and a pin 1 of a resistor ATR7, the anode of the switch diode ATD2 is grounded, and a pin 2 of the resistor ATR7 is connected with a pin PB1 and a pin PD2 of an ATMEGA8A chip; three GND pins of the ATMEGA8A chip are grounded, two VCC pins, an AVCC pin and an AREF pin are connected with a VCC _ AT end of a three-position wiring terminal J2 of the USB power supply circuit, pins PB6 and PB7 of the ATMEGA8A chip are respectively connected with pin 1 and pin 2 of a crystal oscillator Y2, pin 1 of the crystal oscillator Y2 is connected with pin 2 of a capacitor ATC8, pin 2 of the crystal oscillator Y2 is connected with pin 2 of a capacitor ATC9, and pin 1 of the capacitor ATC8 is connected with pin 1 of the capacitor ATC9 and both are grounded; a PC1 pin of the ATMEGA8A chip is connected with the cathode of the light-emitting diode LED4, a PC0 pin of the ATMEGA8A chip is connected with the cathode of the light-emitting diode LED5, the anode of the light-emitting diode LED4 is connected with a pin 1 of a resistor ATR9, the anode of the light-emitting diode LED5 is connected with a pin 1 of an ATR10, a pin 2 of the resistor ATR9 is connected with a pin 2 of a resistor ATR10, and the pins are connected with a VCC _ AT end of a three-position wiring terminal J2 of the USB power supply circuit; the PC6 of the ATMEGA8A chip is connected with a pin 1 of a two-position connecting terminal J1, the PD2 of the ATMEGA8A chip is connected with a pin 2 of a resistor ATR8, and a pin 1 of a resistor ATR8 is connected with a VCC _ AT end of a three-position connecting terminal J2 of the USB power supply circuit; pin 2 of the two-bit terminal J1 is connected to the PB2 pin of the ATMEGA8A chip; RESET, SCK, MOSI and MISO pins of the ATMEGA8A chip are respectively connected with RESET, P1.6, P1.5 and P1.7 pins of the AT series 51 singlechip; one side of the capacitor C10 is connected with the VCC _ STC end of the three-position wiring terminal J2 of the USB power supply circuit, and the other side is connected with the VCC _ AT end of the three-position wiring terminal J2 of the USB power supply circuit.

7. the comprehensive ability training platform based on 51-singlechip pin and jack combination as claimed in claim 1, wherein the circuit of the thermal resistance temperature sensor module comprises: the VIN terminal VCC of the REF3030 chip is connected with the pin 2 of WD _ C1 and is connected to GND through the pin 1 of WD _ C1; the VOUT of the REF3030 chip is connected with a pin 1 of WD _ R1 and a pin 1 of WD _ R2, a pin 2 of WD _ R1 is connected with a pin 2 of PT100 and is also connected with a pin 1 of WD _ R4, the pin 2 of WD _ R4 is connected with a pin 2 of WD-LM340 and is also connected with a pin 1 of WD _ R6, and a pin 2 of WD _ R6 is connected with an output OUT end; pin 2 of WD _ R2 is connected to pin 1 of WD _ R3 and pin 1 of WD _ R5, pin 2 of WD _ R3 is connected to GND, pin 2 of WD _ R5 is connected to pin 1 of WD-LM340, pin 2 of WD _ R5 is connected to pin 2 of pull-up resistor WD _ R7, and pin 1 of WD _ R7 is connected to VCC; the GND end of the REF3030 chip is connected with GND; pin 1 of PT100 is connected to GND.

8. the comprehensive ability training platform based on 51-singlechip pin jack combination as claimed in claim 1, wherein the circuit of the hall sensor module comprises: the VCC end of ACS712 is connected to VCC and then to pin 1 of 712_ C1, and pin 2 of 712_ C1 is connected to GND; VIOUT of ACS712 is brought OUT to the OUT terminal; the FILTER terminal of ACS712 is connected to pin 1 of 712_ C2, and then connected to GND through pin 2 of 712_ C2; GND of ACS712 is terminated with GND; the 4 input ends of ACS712 are connected in parallel to form two pins, pin 1 and pin 2, which are led out and connected to 712_ P1 respectively; where 712_ C1 is a capacitance of 0.1 μ F and 712_ C2 is a capacitance of 104.

Technical Field

the invention relates to a single-chip microcomputer platform for teaching and practical training, in particular to a comprehensive capability practical training platform based on combination of 51 single-chip microcomputer contact pins and jacks.

Background

At present, the single chip microcomputer is widely used in various industrial control systems. In teaching, a teacher explains related theoretical knowledge to students through language, but the theoretical knowledge and the practical and manual practice have various differences, and particularly various troubles are encountered in hardware debugging, so that a practical training platform for the students to practice in combination with the theory is necessary.

the 51 SCM is the simplest SCM, and for a person entering the door, after learning the 51 SCM, the person can learn a higher-level and deeper SCM. Various problems exist in the current experimental box, experimental board or practical training platform: 1. although the modules are modularized, the modules are relatively few and are scattered devices, and chips are lacked, so that various chips cannot be skillfully applied through practice; 2. the service cycle is short, the maintainability and the replaceability are poor, the chip is directly welded on the board, and once the chip is damaged, some experiments cannot be carried out; 3. the AT series 51 single chip microcomputer needs to be externally connected with a special downloader or two core boards, and is not easy and inconvenient to use; 4. the hardware connection is fixed, and a user cannot change a hardware circuit according to requirements and cannot realize effective learning through practice.

Application number 201710402527.0's document discloses a real platform system of instructing based on singlechip and embedded, it is various to be used to multiple singlechip and module, but uses different 51 singlechips to need to change nuclear core plate, needs to reconnect, and the download mode also needs to be changed, connects inconveniently, and five nuclear core plates are put on the laboratory sheet and must be increased the area of laboratory sheet moreover, and the quantity of peripheral module also has certain reduction simultaneously.

disclosure of Invention

Aiming at the defects in the prior art, the invention aims to solve the technical problem of providing a comprehensive capability training platform based on 51-singlechip pin and jack combination.

the technical scheme for solving the technical problem is to provide a comprehensive capability training platform based on 51-singlechip pin and jack combination, which is characterized by comprising a Printed Circuit Board (PCB) and a wrapper sheet module; a core circuit and a peripheral circuit are arranged on the printed circuit board PCB; the peripheral circuit controls and realizes corresponding functions through the core circuit; the core circuit comprises a singlechip minimum system, a selective downloading circuit and a USB power supply circuit; the peripheral circuit comprises independent keys, a communication module, a temperature sensor module, a serial-to-parallel module, a transistor array, a parallel-to-serial module, a Darlington transistor, an eight-input NAND gate, an eight-bit buffer, an eight-input trigger, a four-way photoelectric coupler, a display module, an ultrasonic sensor module, a thermal resistance temperature sensor module, a keyboard module, a 3-8 decoder, a 595 latch, a 4-16 decoder, a light emitting diode module, an operational amplifier module, a pull-up resistor module, a switching interface module, an OR gate module, a clock circuit, a dial switch module, a frequency divider module, an I/O expansion module, a relay module, a Hall sensor module, a buzzer module, a three-color lamp module, a four-bit common-cathode common-anode digital tube, a dot matrix module, a precision adjustable resistor, a 573 latch, a DAC conversion module, a 373 latch, a latch, ADC conversion module, resistance module and serial port module.

compared with the prior art, the invention has the beneficial effects that:

1. the mode that the contact pin and the jack are combined is adopted, so that the connection stability is facilitated, the possibility of poor contact is reduced, the use is simple and convenient, and the operation is easy. Each module chip and each component functional pin are led out by matching of a contact pin and a jack, so that the situation that the length of a connecting wire is insufficient is avoided, and the convenience of installation and debugging is improved; compared with a mode of only adopting a contact pin, the wiring between the pins is clearer and quicker; compared with the DuPont wire connection, the connection is more firm and durable, and the possibility of poor contact is reduced; every pin all is furnished with corresponding mark, and the user can know the function and the pin distribution of each module of this platform fast, convenient operation, easily the shang.

the functional pins of each module chip and component are inserted on the chip base or the device pin base through pins and jacks for K2 series (K2A33) plugs, and are fixed on the platform circuit board through the chip base or the device pin base, so that all the pins are led out.

2. Has certain integration. Because the STC series 51 single-chip microcomputer and the AT series 51 single-chip microcomputer have different downloading modes, the AT series 51 single-chip microcomputer needs a special downloader and has complex downloading modes. The platform is respectively connected with AT and STC core chips, each chip is provided with a corresponding downloading circuit, and no additional downloader is needed; and two kinds of download circuits are integrated In one ISP (In-System Programming) download circuit, and the corresponding download circuit can be switched by only changing the access position of the jumper cap, so that the switching is more convenient and quicker, the occupied area is reduced, and the integration is realized.

3. comprehensive peripheral circuit and complete functional modules. Required functional components are automatically expanded on the platform through the bread board module, onboard resources are not limited, the bread board module and the platform share a power supply and a ground, the platform can be used for meeting the requirements of other experiments, and the application is wider. Three common and common sensor modules, namely an ultrasonic sensor module, a Hall sensor module and a thermal resistance temperature sensor module, are added, so that experimental projects which can be carried out are expanded. Different combinations can be carried out among the modules of the peripheral circuit, various experiments can be combined, and the diversity of the experimental types can be realized.

4. The manual practice is effectively realized. The platform only connects the hardware of the download circuit. The actual connection and operation of the pins of the single chip microcomputer and the peripheral chip need to be completed by a user independently, the problems in the connection process and the process are familiar, the user can independently connect the required devices, and the practical value of the platform is realized.

5. Long service life and strong maintainability. If the module has a problem, the module can be replaced by itself, and the maintainability is high.

6. the system has the external expansion and communication mode based on the 485 protocol and the RS232 serial port, and the expandability of the system is ensured.

7. the power supply is realized by adopting the same USB power supply circuit, a switch is arranged in front of a USB interface, the power supply is realized by opening a power switch and changing the access position of a jumper cap to supply power to the minimum system of the single chip microcomputer, the corresponding download circuit and the peripheral circuit, and the single chip microcomputer is independently provided with the power switch.

8. The adapter module is provided with two rows of connecting holes of VCC and GND for the conditions that the connecting wire is too short and a plurality of wires need to be connected to the same interface.

drawings

FIG. 1 is an overall block diagram of the present invention;

FIG. 2 is a circuit diagram of a USB power supply circuit according to the present invention;

FIG. 3 is a circuit diagram of a USB program downloading circuit of an STC series 51 single-chip microcomputer of the invention;

FIG. 4 is a circuit diagram of the USBASP program downloading circuit of the AT series 51 single chip microcomputer of the present invention;

FIG. 5 is a circuit diagram of a thermal resistance temperature sensor module of the present invention;

fig. 6 is a circuit diagram of a hall sensor module of the present invention.

Detailed Description

specific examples of the present invention are given below. The specific examples are only intended to illustrate the invention in further detail and do not limit the scope of protection of the claims of the present application.

The invention provides a comprehensive capability training platform (short for platform) based on 51 singlechip pin jack combination, which is characterized by comprising a Printed Circuit Board (PCB) and a wrapper sheet module 15; a core circuit and a peripheral circuit are arranged on the printed circuit board PCB; the peripheral circuit controls and realizes corresponding functions through the core circuit; the core circuit comprises a singlechip minimum system 1, a selective downloading circuit and a USB power supply circuit 2; the peripheral circuit comprises an independent key 3, a communication module 4, a temperature sensor module 5, a serial-parallel module 6, a transistor array 7, a parallel-serial module 8, a Darlington transistor 9, an eight-input NAND gate 10, an eight-bit buffer 11, an eight-input trigger 12, a four-way photoelectric coupler 13, a display module 14, an ultrasonic sensor module 16, a thermal resistance temperature sensor module 17, a keyboard module 18, a 3-8 decoder 19, a 595 latch 20, a 4-16 decoder 21, a light emitting diode module 22, an operational amplifier module 23, a pull-up resistor module 24, a switching port module 25, an OR gate module 26, a clock circuit 27, a dial switch module 28, a frequency divider module 29, an I/O expansion module 30, a relay module 31, a Hall sensor module 32, a buzzer module 33, a three-color lamp module 34, a four-bit common-cathode common-anode nixie tube 35, The device comprises a dot matrix module 36, a precision adjustable resistor 37, a 573 latch 38, a DAC conversion module 39, a 373 latch 40, an ADC conversion module 41, a resistor module 42 and a serial port module 43.

The single chip microcomputer minimum system 1 comprises an STC series 51 single chip microcomputer, an AT series 51 single chip microcomputer, a crystal oscillator circuit, a reset circuit and contact pins and jacks led out from interfaces of the single chip microcomputer.

The selective downloading circuit and the USB power supply circuit 2 comprise a USB power supply circuit, an STC series 51 single-chip microcomputer USB program downloading circuit and an AT series 51 single-chip microcomputer USBASP program downloading circuit, and are used for power supply and program downloading of the whole platform; the USB power supply circuit is simultaneously connected with the STC series 51 single-chip microcomputer USB program downloading circuit and the AT series 51 single-chip microcomputer USBASP program downloading circuit, the USB power supply circuit is connected with the jumper cap, and the corresponding downloading circuit of the single-chip microcomputer is selected by changing the access position of the jumper cap; the STC series 51 single chip microcomputer is connected with an STC series 51 single chip microcomputer USB program downloading circuit, and the AT series 51 single chip microcomputer is connected with an AT series 51 single chip microcomputer USBASP program downloading circuit;

The circuit of the USB power supply circuit is (see FIG. 2): assuming that pin No. 1 in 4 pins of the USB interface is a power supply, pin No. 2 is D-, pin No. 3 is D + and pin No. 4 is a power supply ground; the GND end of the USB interface is connected with GND; pin 1 of the capacitor J2C1 and pin 1 of the electrolytic capacitor J2C2 are connected with a VCC end of the USB interface, and pin 2 of the capacitor J2C1 and pin 2 of the electrolytic capacitor J2C2 are both connected with GND; pin 1 of fuse F1 is connected to pin 1 of electrolytic capacitor J2C2, pin 2 of fuse F1 is connected to pin 1 of switch SW, and pin 2 of switch SW is connected to pin 1 of resistor J2R 1; pin 2 of the resistor J2R1 is connected to the anode of the LED1, and the cathode of the LED1 is grounded; pin 2 of the switch SW is used as VCC and connected with pin 2 of the three-position wiring terminal J2, and pin 1 and pin 3 of the three-position wiring terminal J2 are respectively used as power supplies of an AT series 51 single chip microcomputer and an STC series 51 single chip microcomputer and are respectively marked as VCC _ AT and VCC _ STC; the VCC _ AT is terminated with a pin 1 of the resistor J2R2, and then is connected with the anode of the LED2 through a pin 2 of the J2R2, and the cathode of the LED2 is grounded; VCC _ STC is terminated with pin 1 of resistor J2R3, and then is connected with the anode of LED3 through pin 2 of J2R3, and the cathode of LED3 is grounded; the VCC _ AT end and the pin 2 of the three-position wiring terminal J2 are respectively connected through a jumper cap, so that power supply for the USBASP program downloading circuit of the AT series 51 single-chip microcomputer is realized; the pin 2 of the three-position wiring terminal J2 and a VCC _ STC end are respectively connected through a jumper cap, so that power supply for a USB program downloading circuit of an STC series 51 single-chip microcomputer is realized; wherein the resistance values of J2R1, J2R2 and J2R3 are 1K omega, the capacitance value of the electrolytic capacitor J2C2 is 10 muF, and the capacitance value of the capacitor J2C1 is 0.1 muF.

the circuit structure of the STC series 51 singlechip USB program downloading circuit is as follows (see figure 3): pin 1 of the electrolytic capacitor STCC3, pin 1 of the capacitor STCC4 and a VCC pin of the CH340 chip are connected with a VCC _ STC end of a three-position wiring terminal J2 of the USB power supply circuit; pin 2 of the electrolytic capacitor STCC3, pin 2 of the capacitor STCC4, pin 2 of the capacitor STCC5 and a GND pin of the CH340 chip are all connected with GND; pin 1 of the capacitor STCC5 is connected with pin V3 of the CH340 chip; the D-end of the USB interface of the USB power supply circuit is connected with the VD-pin of the CH340 chip, the D + end of the USB interface of the USB power supply circuit is connected with the VD + pin of the CH340 chip, the X0 and X1 pins of the CH340 chip are respectively connected with the pin 1 and the pin 2 of the crystal oscillator Y1, the pin 1 of the crystal oscillator Y1 is connected with the pin 2 of the capacitor STCC7, the pin 2 of the crystal oscillator Y1 is connected with the pin 1 of the capacitor STCC6, and the pin 2 of the STCC6 is connected with the pin 1 of the STCC7 and is grounded; a TXD pin of the CH340 chip is connected with the cathode of a Schottky diode CH340D3, and the anode of the Schottky diode CH340D3 is connected with an RXD (P3.0) pin of an STC series 51 single chip microcomputer; the RXD pin of the CH340 chip is connected with a pin 1 of a resistor STCR4, and a pin 2 of a resistor STCR4 is connected with a TXD (P3.1) pin of an STC series 51 single chip microcomputer; the capacitance value of the electrolytic capacitor STCC3 is 22 muF, the capacitance value of the capacitor STCC4 is 0.1 muF, the capacitance value of the capacitor STCC5 is 0.01 muF, the capacitance values of the capacitors STCC6 and STCC7 are both 22pF, the crystal oscillator Y1 is 12MHz, and the resistance value of the STCR4 is 1K omega.

the circuit of AT series 51 singlechip USBASP program download circuit constitutes (see fig. 4): the D-of USB interface of the USB power supply circuit connects the negative pole of the switching diode ATD1, pin 1 of resistor ATR5 and pin 1 of resistor ATR6, the positive pole of the switching diode ATD1 is grounded, pin 2 of resistor ATR5 connects VCC _ AT end of three-position connecting terminal J2 of the USB power supply circuit, pin 2 of resistor ATR6 connects PB0 pin of ATMEGA8A chip; the D + of the USB interface of the USB power supply circuit is connected with the cathode of a switch diode ATD2 and a pin 1 of a resistor ATR7, the anode of the switch diode ATD2 is grounded, and a pin 2 of the resistor ATR7 is connected with a pin PB1 and a pin PD2 of an ATMEGA8A chip; three GND pins of the ATMEGA8A chip are grounded, two VCC pins, an AVCC pin and an AREF pin are connected with a VCC _ AT end of a three-position wiring terminal J2 of the USB power supply circuit, pins PB6 and PB7 of the ATMEGA8A chip are respectively connected with pin 1 and pin 2 of a crystal oscillator Y2, pin 1 of the crystal oscillator Y2 is connected with pin 2 of a capacitor ATC8, pin 2 of the crystal oscillator Y2 is connected with pin 2 of a capacitor ATC9, and pin 1 of the capacitor ATC8 is connected with pin 1 of the capacitor ATC9 and both are grounded; a PC1 pin of the ATMEGA8A chip is connected with the cathode of the light-emitting diode LED4, a PC0 pin of the ATMEGA8A chip is connected with the cathode of the light-emitting diode LED5, the anode of the light-emitting diode LED4 is connected with a pin 1 of a resistor ATR9, the anode of the light-emitting diode LED5 is connected with a pin 1 of an ATR10, a pin 2 of the resistor ATR9 is connected with a pin 2 of a resistor ATR10, and the pins are connected with a VCC _ AT end of a three-position wiring terminal J2 of the USB power supply circuit; the PC6 of the ATMEGA8A chip is connected with a pin 1 of a two-position connecting terminal J1, the PD2 of the ATMEGA8A chip is connected with a pin 2 of a resistor ATR8, and a pin 1 of a resistor ATR8 is connected with a VCC _ AT end of a three-position connecting terminal J2 of the USB power supply circuit; pin 2 of the two-bit terminal J1 is connected to the PB2 pin of the ATMEGA8A chip; RESET, SCK, MOSI and MISO pins of the ATMEGA8A chip are respectively connected with RESET, P1.6, P1.5 and P1.7 pins of the AT series 51 singlechip; one side of the capacitor C10 is connected with a VCC _ STC end of a three-position wiring terminal J2 of the USB power supply circuit, and the other side of the capacitor C10 is connected with a VCC _ AT end of a three-position wiring terminal J2 of the USB power supply circuit, and is used for filtering two power supplies and reducing the interference between the power supplies; wherein the resistance of ATR5 is 2.2K Ω, the resistance of ATR6 and ATR7 is 68 Ω, the resistance of ATR8 is 10K Ω, the resistance of ATR9 and ATR10 is 1K Ω, and the capacitance of ATC8 and ATC9 is 27 pF; the capacitance value of the capacitor C10 is 0.1 muF; the crystal oscillator Y2 is 12 MHz; the switching diodes ATD1 and ATD2 are 1N 4148.

The independent keys 3 adopt 8 four-foot keys and can be used for corresponding control experiments;

The communication module 4 is in a 485 communication mode, the used core chip is MAX487, and a user can communicate and expand in a 485 bus mode;

The temperature sensor module 5 comprises a DS18B20 type temperature sensor and an AD590 type temperature sensor, and one of the temperature sensors can be selected for measuring temperature; the output current of the AD590 type temperature sensor is proportional to the absolute temperature, the temperature is measured through the output current, the measurement precision is high, and the method is used for industrial application; the DS18B20 type temperature sensor directly outputs digital signals, has a large temperature range and is used for conventional measurement;

The serial-to-parallel module 6 adopts a 74LS164 chip, and can realize 2-bit serial input and 16-bit parallel output at most;

the transistor array 7 adopts two ULN2803 chips, and the ULN2803 chips are 8-bit drivers;

the parallel-serial module 8 adopts a 74LS165 chip, and can realize 16-bit parallel input and 2-bit serial output;

The darlington transistor 9 adopts two ULN2003 chips, and the ULN2003 chip is a driver of 7-bit data;

the eight-input nand gate 10 adopts a 74LS30 chip (positive logic), and a user can output 1 signal after performing logical AND and logical NOT operation on 8 input signals;

the eight-bit buffer 11 adopts a 74LS244 chip, a user can input data through 8 data input ends, and the data can be output in a four-bit binary form;

The eight-input flip-flop 12 employs a 74LS273 chip, an 8-bit data/address latch, through which a user can operate on the currently displayed data;

the four-way photoelectric coupler 13 adopts a TLP521-4 chip, can be used for inputting and outputting 4-way signals at most, and can improve the stability of the signals;

the display module 14 comprises a number LCD1602 type display and an LCD12864 type display, which can be used for data display, and the LCD12864 type display can be used for Chinese character and graphic display;

the bread board module 15 is connected with a power supply, so that a user can conveniently and automatically expand equipment such as a direct current motor without being limited to onboard resources;

the ultrasonic sensor module 16 adopts an HC-SR04 type ultrasonic sensor;

the thermal resistance temperature sensor module 17 adopts a PT100 thermal resistance temperature sensor, and measures the temperature by using the principle that the resistance value of a conductor can change along with the change of the temperature; a voltage stabilizing chip REF3030 is used for supplying power to the thermal resistance temperature sensor module;

the circuit configuration of the thermal resistance temperature sensor module 17 is (see fig. 5): the VIN terminal VCC of the REF3030 chip is connected with the pin 2 of WD _ C1 and is connected to GND through the pin 1 of WD _ C1; the VOUT of the REF3030 chip is connected with a pin 1 of WD _ R1 and a pin 1 of WD _ R2, a pin 2 of WD _ R1 is connected with a pin 2 of PT100 and is also connected with a pin 1 of WD _ R4, the pin 2 of WD _ R4 is connected with a pin 2 of WD-LM340 and is also connected with a pin 1 of WD _ R6, and a pin 2 of WD _ R6 is connected with an output OUT end; pin 2 of WD _ R2 is connected to pin 1 of WD _ R3 and pin 1 of WD _ R5, pin 2 of WD _ R3 is connected to GND, pin 2 of WD _ R5 is connected to pin 1 of WD-LM340, pin 2 of WD _ R5 is connected to pin 2 of pull-up resistor WD _ R7, and pin 1 of WD _ R7 is connected to VCC; the GND end of the REF3030 chip is connected with GND; pin 1 of PT100 is connected with GND; wherein WD _ R1, WD _ R2, WD _ R3, WD _ R4 and WD _ R5 are 1K resistors, and WD _ R6 and WD _ R7 are 100K resistors; WD _ C1 is a capacitance of 0.1 μ F.

The keyboard module 18 adopts a 4 × 4 keyboard, has 16 four-pin switches, can be used as a matrix keyboard according to hardware circuit connection, and can also be used as an independent key by singly connecting out a key;

the 3-8 decoder 19 adopts a 74LS138 or 74HC138 chip, and can realize data decoding conversion from three lines to eight lines;

The 595 latch 20 adopts two 74HC595 chips, and each 74HC595 chip can realize the input and latch of 7-bit data, for example, for the data driving display of a nixie tube;

the 4-16 decoder 21 adopts a 74LS154 or 74HC154 chip, and can be used for decoding 4-bit data and converting the data into 16-bit output;

The light-emitting diode module 22 adopts an LED bulb light-emitting diode of type F3, the diameter of the light-emitting diode module is 3mm, the light-emitting diode module is composed of 8 light-emitting diodes additionally provided with current-limiting resistors, and each light-emitting diode is marked with an anode and a cathode;

The operational amplifier module 23 adopts a four-way operational amplifier LM324 chip, is used by combining a photoelectric coupler, and can be used for detecting weak signals;

The pull-up resistor module 24 adopts a pull-up resistor array of 10K;

The adapter interface module 25 comprises 8 1-to-1-wire interfaces, 4 1-to-2-wire interfaces and 2 8-bit pull-up resistors, so that the problem that multiple wires need to be connected to the same interface due to insufficient length of the DuPont wires or during some experiments can be solved, and the pull-up of parallel data ports of some devices can be realized;

the or gate module 26 adopts a 74HC02 chip, and can realize the logical or-not relational operation;

the clock circuit 27 adopts a DS1302 chip, which comprises 1 external battery, 1 DS1302 chip, 1 crystal oscillator and 2 capacitors, and can be used for corresponding experiments for displaying time;

The dial switch module 28 adopts an 8-bit dial switch, can be used for digital quantity input experiments and can be used for 16-bit binary number input at most, and is convenient for a user to carry out experiments such as parallel-serial conversion, D/A conversion and the like;

The frequency divider module 29 adopts a 74HC4040 chip, and can realize multi-stage frequency division from 2 to 512;

the I/O expansion module 30 adopts 8255 chip, and can expand one eight-bit data port on the single chip into three eight-bit data ports;

the relay module 31 adopts two paths of relays, and the output ends of the relays are connected by wiring terminals;

the Hall sensor module 32 adopts a current type Hall sensor with the model number of ACS 712;

The circuit configuration of the hall sensor module 32 is (see fig. 6): the VCC end of ACS712 is connected to VCC and then to pin 1 of 712_ C1, and pin 2 of 712_ C1 is connected to GND; VIOUT of ACS712 is brought OUT to the OUT terminal; the FILTER terminal of ACS712 is connected to pin 1 of 712_ C2, and then connected to GND through pin 2 of 712_ C2; GND of ACS712 is terminated with GND; the 4 input ends of ACS712 are connected in parallel to form two pins, pin 1 and pin 2, which are led out and connected to 712_ P1 respectively; where 712_ C1 is a capacitance of 0.1 μ F and 712_ C2 is a capacitance of 104.

The buzzer module 33 adopts a 5V passive buzzer, two ends of the buzzer are led out by pins, and the positive and negative of the buzzer are marked;

The three-color lamp module 34 adopts LED lamp beads 5050RGB, and the RGB three-color lamp is composed of two patch type RGB adjustable diodes;

The four-bit common cathode common anode nixie tube 35 adopts HS41056K-D30 and HS41056K-32 models, and can be used for displaying four-bit data;

the dot matrix module 36 adopts an 8 × 8 LED dot matrix, and a user can display characters or graphics by programming and building a circuit;

the precision adjustable resistor 37 adopts a 10K adjustable resistor;

573 the latch 38 employs two 74HC573 chips for eight-bit data latching;

The DAC0832 chip is adopted by the DAC conversion module 39 and can be used for D/A conversion experiments;

The 373 latch 40 is a 74LS373 chip, and is an eight-bit data latch, which can be used to provide address and data latches for the DAC conversion module 39;

The ADC conversion module 41 adopts an ADC0809 chip and can be used for an A/D conversion experiment;

the resistance module 42 employs two 1K resistors and one 0.5K resistor;

The core chip used by the serial port module 43 is MAX232, and is respectively connected with a male head and a female head of DB9, and the control ends of the male head and the female head are both led out by pins, so that the user can select the required port by means of 232 bus according to the system requirement.

Nothing in this specification is said to apply to the prior art.