CN2684271Y

CN2684271Y - Experiment display device for teaching

Info

Publication number: CN2684271Y
Application number: CN 200420021043
Authority: CN
Inventors: 张建民
Original assignee: Individual
Current assignee: Zhang Jianguo
Priority date: 2004-03-18
Filing date: 2004-03-18
Publication date: 2005-03-09
Anticipated expiration: 2014-03-18

Abstract

The utility model relates to an experiment display device for teaching, which belongs to the technical field of data collection and process. The utility model is composed of a sensor, a data collector and a computer which are connected, and is characterized in that the data collector is composed of a standard interface, a PC filter, an ADC, a microprocessor a memory and a USB communication controller which are connected. The experiment display device for teaching can directly receive data and record data. In addition, the experiment display device for teaching can calculate and process data, and directly draw experiment function curves. The experiment results can be displayed on the screen. The implementation and popularization of the experiment display device for teaching makes the experimental methods have new development. Furthermore, the experiment display device for teaching creates conditions for the field grasping and gradual assimilation of students in the course of an experiment.

Description

A kind of experiment display device of the usefulness of imparting knowledge to students

Technical field: the utility model belongs to data acquisition, processing technology field.

Background technology: China's middle school physical and chemical experiment teaching at present also rests on manual mode of operation, hand-kept experimental data, hand computation, manual drawing experiment function curve.Not only time-consuming, and can not concentrate on the observation of experimental phenomena with analytically, especially, be difficult to observe to some subtle change signals and instantaneous variation signal, also certainly will influence experiment effect.Along with going deep into of educational reform, laboratory facilities have been proposed to want strong operability, measured accurately, the student can be understanded at the scene, and progressively reached the requirement of digesting.

Summary of the invention: the utility model is will provide a kind of directly to receive data, record data by proving installation, calculates and deal with data, and directly draws behind the function curve experimental result the most at last and be presented at a kind of teaching on the screen with the experiment display device.

Technical solution adopted in the utility model is:

Direct and the sensor input end associated of experimental provision, sensor output is connected with the input end of data acquisition unit, and the output terminal of data acquisition unit is connected with computing machine.

The input end of data acquisition unit is four, and the interface output terminal joins with analog to digital converter after by RC Shanghai ripple device respectively with the standard interface of 6 data lines, more successively with microprocessor, storer is connected, and joins by communication controler and its interface and computing machine.The data acquisition unit power supply is supplied with by computing machine by communication interface.And adopt electrostatic prevention chip and short circuit to protect chip.

After implementing the utility model, because can be to the data high speed acquisition, storage so can in time catch transient signal, also because its high sensitivity can both be observed tiny signal and transient signal, Yi Bian do experiment, Yi Bian just run a curve, is seen the result.Student's scientific theory of can concentrating one's energy to understand has been avoided the energy expense on trifling odd job and grab shortcoming less than the experiment main points.

Description of drawings:

Fig. 1 is for system forms and theory diagram;

Fig. 2, standard interface and signal filtering;

Fig. 3, analog to digital conversion, data storage, and microprocessor;

Fig. 4, usb communication control and power supply;

Fig. 5, experiment is provided with and the initialization module flow process;

Fig. 6, the data acquisition module flow process;

Fig. 7, Data Processing in Experiment module flow process.

Embodiment:

By sensor, the data acquisition unit composition native system that is connected with computing machine, wherein data acquisition unit by input end be four respectively with the standard interface of six roots of sensation data line, wave filter and analog to digital conversion U that the interface output terminal is formed by RC ₄Join, and successively with microprocessor U ₁, storer U ₃And and usb communication controller U ₁₁Be connected with its interface.The power supply power supply of data acquisition unit is to be connected with the power end of computing machine by the usb communication interface to obtain power supply.And adopt an electrostatic prevention chip U ₁₈With short circuit protection chip F ₁

Now the utility model is described in further detail in conjunction with each accompanying drawing.

Fig. 2 is standard interface and signal filtering,

Standard signal by sensor and probe output is input to collector by standard interface 1, and system adopts electrostatic prevention chip U ₁₈With short circuit protection chip F ₁Docking port carries out electrostatic prevention and the protection of anti-short circuit, and wherein the first line AIN of standard interface is the sensor circuit voltage signal processed, and it is directly connected to part 2, by R ₄₁And C ₃₇The rc filter circuit filtering unwanted frequency signal of forming is exported in the 3rd part afterwards.

Native system has four interfaces, can gather four kinds of signal datas simultaneously, and the circuit theory of constitution of four interfaces is identical.

Compatible standard interface definition is as follows:

The part that sensing system is connected with collector systems is made up of six roots of sensation data, and is specific as follows:

The 1st line: AIN: simulating signal incoming line

The 2nd line: VCC: direct supply+5V is for external sensor and treatment circuit provide power supply

The 3rd line: Trig: manual triggers signal wire, the acquisition time of manual control data collector

4:E-ID/Vres: the automatic recognition data line of probe, the automatically PORT COM of identification probe/provide reference voltage for external probes

The 5th line: GND: direct current ground

Other signal input ports that the 6th line: DIN reserves

Fig. 3 is analog to digital conversion, data storage and microprocessor portion

Input to analog to digital converter U through the four useful circuit-switched data voltage signals after the filtering through the 4th part ₄, analog to digital converter adopts high speed analog-to-digital conversion chip MAX154 or AD7824, U ₄Become digital signal to pass through the output of the 5th part analog signal conversion, native system can be changed the simulating signal of four passages simultaneously, and the analog to digital conversion control section by the 6th part when converting is given single-chip microcomputer U ₁INTO signalling level notice single-chip microcomputer, the data after single-chip microcomputer will be changed are read.Be the very high signal data of frequency acquisition, need the data of gathering are stored temporarily that native system adopts the sram chip HY62256 of 32KB capacity as data-carrier store U ₃, single-chip microcomputer U ₁P ₂Mouth and U ₃Address bus connect, receive the request of data of computing machine when single-chip microcomputer after, read data in the respective memory address, and control the usb communication controller by the 8th part by the control address bus, and transfer data to the usb communication controller, output to computing machine for it.

U wherein ₂Be that 74HCT373 is a data latches; U ₅Be that 74LS245 is the triple gate impact damper.

The 7th part is the reference voltage of analog to digital converter, native system with the supply voltage of+5V as reference voltage.

The 9th part is microprocessor U ₁Part:

Be the control center of whole collector, mainly be the control data frequency of gathering to the storage control of the data of gathering and with the Control on Communication of computer software, U ₁Adopt the high-performance single chip computer AT 89C52 of ATMEL to constitute, built-in 8KFLASH storer, compatible C Programming with Pascal Language runs on the fast state of 24M, guarantees the accuracy and the integrality of data acquisition.

All acquired signal instructions, the storage data command, the Communication Control instruction is all by its control.

Preserved the control program of data acquisition in the built-in 8K FLASH storer of microprocessor, the steering order of this program receiving computer software is also carried out data acquisition and the work of data transmission.Program description is as follows:

A. initialization

After collector passed through the USB connecting line and computing machine normally is connected, computing machine was powered to collector, and single-chip microcomputer begins initial work, enters the circular wait state afterwards.

B. wait for: single-chip microcomputer enters the attitude of awaiting orders, and the inquiry communication port is prepared to take orders.

C. order receives: after single-chip microcomputer receives command frame, enter the order analysis processing procedure, the arrangement input parameter.If can not differentiate the order that identification is received, then return the computation error frame.If order is correct, enter command processing module.

D. command process: single-chip microcomputer resolve command frame, carry out data acquisition according to the requirement of order, the total data of control sampling time, sampling counts, judges that the buffer-stored of the line data of going forward side by side distributes, and gathers to enter the data back module after finishing.

E. data back: will transfer data to computing machine after the intact data of single-chip microcomputer collection, reenter waiting status after the end of transmission (EOT).

Fig. 4 is usb communication control and power unit

Computing machine is by the 15th part Universal USB connecting interface J ₂Be connected with data acquisition unit, interface by the 14th part by computing machine for total system provide+direct supply of 5V makes native system not need external power supply; Computing machine is by the 13rd partial data line and 16 part U ₁₁Be connected and carry out the instruction between computing machine and the collector and the transmission of data, the 16th part is the usb communication controller, chip U ₁₁The PDIUSBD12 that adopts PHILPS company to produce, its expansion is on the data bus of single chip computer AT 89C52 (i.e. the 10th part), and adopt the USB1.1 communication protocol of standard: it is that the usb communication controller is realized the data communication between collector and the computing machine that single-chip microcomputer is controlled the 16th part by the control line of the 11st part; Simultaneously, the 12nd part is a USB PORT COM working station indicator, if this pilot lamp is long bright, shows that system is current to have activated and used the USB PORT COM; If the flicker of this pilot lamp, show system current with the computing machine communication; If this pilot lamp does not work, show the current use USB port that activates of system.

The data collection task process flow diagram is by shown in Figure 5.

The Data Processing in Experiment program is by shown in Figure 6

Experiment is provided with and initialization, and its operating process is by shown in Figure 7.

Claims

1, a kind of experiment display device of the usefulness of imparting knowledge to students, by sensor, data acquisition unit, computing machine be connected form, it is characterized in that: data acquisition unit by input end be four respectively with the standard interface of six roots of sensation data line, wave filter and analog to digital conversion (U that the interface output terminal is formed by RC ₄) join, and successively with microprocessor (U ₁), storer (U ₃), and and usb communication controller (U ₁₁) be connected with its interface form.

2, experiment display device according to claim 1 is characterized in that: described data acquisition unit is that power supply+5V input end is connected with the power source supply end of computing machine by the usb communication interface.

3, experiment display device according to claim 1 is characterized in that: the interface of described data acquisition unit has an electrostatic prevention chip U ₁₈Protect chip F with short circuit ₁