CN203232617U

CN203232617U - Laboratory experiment board

Info

Publication number: CN203232617U
Application number: CN 201320222172
Authority: CN
Inventors: 王晓惠; 周金陵
Original assignee: Hohai University HHU
Current assignee: Hohai University HHU
Priority date: 2013-04-26
Filing date: 2013-04-26
Publication date: 2013-10-09
Anticipated expiration: 2023-04-26

Abstract

The utility model discloses a laboratory experiment board, comprising a JTAG interface, a buffer, a pull-up resistor, a pull-down resistor, an A/D conversion module, a digital display module, a traffic light simulation module, a keyboard module, a stepping motor driving module and a serial interface module, wherein the JTAG interface and all the components are integrated on a board, the JTAG interface is connected with the buffer through the pull-up resistor, and the buffer is connected with a reset terminal of a one-chip microcomputer through the pull-down resistor. The laboratory experiment board provided by the utility model can only be used in a laboratory environment, which is convenient for laboratory management; meanwhile, a plurality of functional modules are integrated, so basic demands of a user are met, and complexity of experiment operation is reduced.

Description

A kind of laboratory experiment plate

Technical field

The utility model relates to the teaching aid technical field, particularly a kind of laboratory experiment plate.

Background technology

Brassboard is the hardware module that is provided with multiple effect, with the hardware system that some interface circuits commonly used are built, is commonly used in resource and the environment of simulating embedded system experiment in experiment and the teaching.

Because the brassboard stable performance, simple to operate, study is convenient, relates to experiment that single-chip microcomputer will do nearly all with obtaining; But the user frequently uses brassboard, and management brings numerous inconvenience to laboratory equipment.Brassboard of tradition is functional comprehensive inadequately, when carrying out numerous experiments conversion, needs the external circuits chip, perhaps need use experimental box, has caused the loaded down with trivial details and complicacy of experiment.

In addition, the JTAG programming mode is online programming, earlier chip is carried out pre-programmed in the traditional mode of production flow process and refills on the plank, simplifies flow process and be first immobilising device to circuit board, again with the JTAG programming, thereby speeds up the work greatly.Jtag interface can be programmed to all devices of chip internal.

Summary of the invention

Utility model purpose: make things convenient for the laboratory equipment management, design a kind of can only under laboratory environment, work, leave the laboratory experiment plate that can't work alone under the laboratory environment.

Technical scheme: a kind of laboratory experiment plate comprises jtag interface, impact damper, pull-up resistor and pull down resistor; Also comprise A/D modular converter, digital display module, traffic lights analog module, Keysheet module, stepper motor driver module, serial interface module; Jtag interface and each components and parts are integrated on the plate.Wherein, use pull-up resistor to connect between jtag interface and the impact damper, use pull down resistor to connect between impact damper and the single-chip microcomputer reset terminal.

The utility model adopts technique scheme, has following beneficial effect: 1, the design of pull-up resistor and pull down resistor makes when laboratory environment leaves in experiment class that subsequent conditioning circuit can't operate as normal; 2, because 25 pin parallel interfaces can only be used at laboratory computer, and notebook is not equipped with this parallel port design, this design has guaranteed that brassboard can only use under laboratory environment, make things convenient for the function of laboratory equipment management.3, the most experiential functions of integrated single-chip microcomputer can be satisfied substantially for user's requirement.4, test required components and parts, JTAG program download interface all is integrated on the plank, reduces the complicacy of experiment, and outward appearance is neatly compact.

Description of drawings

Fig. 1 is the circuit theory synoptic diagram of the utility model embodiment;

Fig. 2 is the structured flowchart of the utility model embodiment.

Embodiment

Below in conjunction with specific embodiment, further illustrate the utility model, should understand these embodiment only is used for explanation the utility model and is not used in restriction scope of the present utility model, after having read the utility model, those skilled in the art all fall within the application's claims institute restricted portion to the modification of the various equivalent form of values of the present utility model.

A kind of embodiment of brassboard comprises jtag interface, the ternary non-inverting buffer of 74LVC244, pull-up resistor and pull down resistor; Also comprise A/D modular converter, LCD display module, LED traffic lights analog module, Keysheet module, stepper motor driver module, RS232 or RS485 serial interface module; Jtag interface and each components and parts are integrated on the plate.Wherein, use pull-up resistor to connect between jtag interface and the 74LVC244, use pull down resistor to connect between 74LVC244 and the single-chip microcomputer reset terminal.The A/D modular converter becomes digital signal to analog signal conversion; LCD shows to test and shows with the various counters of emulation, numeral and make emulation such as electronic clock of single-chip microcomputer.Such as counter, stopwatch, electronic clock etc.; The LED running lamp can show the state of P mouth, and test and emulation teacher's study course, such as positive and negative running lamp, and traffic indication etc.; Keyboard can be tested the program relevant with emulation user's keyboard; Contain RS232, the RS485 interface is supported the serial communication experiment; Contain stepper motor driving circuit on the plate, can connect stepper motor easily, finish all kinds of experiments of stepper motor, as forward and backward of motor etc.; The output of software modulation FSK, the modulation and demodulation of realization fsk signal.

The concrete working method of this brassboard is:

JTAG routine interface pin 1,17 is connected to 74LVC244 pin 1,19(1G by connecting pull-up resistor, 2G: the output enable end), when the parallel port is connected with the signal input under the laboratory environment, pin 1,19(1G, 2G: the output enable end) be low level, the circuit operate as normal; Leaving the laboratory environment parallel port connects when disconnecting, pull-up resistor works, the output high level is to 1 of 74LVC244,19 pin (1G, 2G: the output enable end), because output enable end low level is effective, no matter the input of ternary non-inverting buffer 74LVC244 input end is high or low level, output terminal all is high impedances, this moment output in vacant state, data output end) and single-chip microcomputer pin 94(RST 74LVC244 pin 9(2Y1:: the pull down resistor reset terminal) works, output low level is to the single-chip microcomputer reset terminal, the reset terminal low level is effective, and single-chip microcomputer is in reset mode always, and subsequent conditioning circuit can't operate as normal.This design has guaranteed that brassboard can only use, and leaves the function that laboratory environment then can't work alone under laboratory environment.

Claims

1. a laboratory experiment plate is characterized in that, comprises jtag interface, impact damper, pull-up resistor and pull down resistor; Use pull-up resistor to connect between jtag interface and the impact damper output enable end, use pull down resistor to connect between buffer output end and the single-chip microcomputer reset terminal.

2. a kind of laboratory experiment plate according to claim 1 is characterized in that: also comprise A/D modular converter, digital display module, traffic lights analog module, Keysheet module, stepper motor driver module, serial interface module.

3. a kind of laboratory experiment plate according to claim 1, it is characterized in that: impact damper is 74LVC244.

4. a kind of laboratory experiment plate according to claim 2, it is characterized in that: serial interface module is RS232 or RS485.