Design Of Data Acquisition And Analysis System Based On Virtual Instrument Technology

In the fields of experimental teaching,electronic measurement and so on,the traditional experimental instruments are often accompanied by many problems,such as high cost of purchasing,time consuming and energy consumption of equipment's maintenance and technology updates,which lead to the shortage of testing instruments and backward technology in the field.The appearance of virtual instrument has effectively changed this situation,and the application of virtual instrument in the fields of experimental teaching and electronic measurement will highlight its economic practicality,through the upgrading of software,it can effectively change and improve the experimental means and quality of teaching.This thesis designs a cost-effective data acquisition and analysis system based on the virtual instrument technology,its function covers the high price oscilloscope,signal generator and spectrum analyzer in the fields of experimental teaching and electronic measurement.In this thesis,The main points of the work are as follows:(1)The lower computer uses ST company's latest cost-effective performance embedded microprocessor chip STM32F407,which can realize high-speed AD acquisition of multichannel signals,embedded USB module,and support USB 2.0 data transmission protocol.The program is developed according to the characteristics of USB module embedded in STM32F407,including the firmware program running in the STM32F407,the driver running on the PC machine and the debugging application development.Firmware development uses USB driver library provided by ST,and PC driver is developed by LibUSB toolkit.(2)The host computer software platform selects a new type of graphical user interface development mode MATLAB GUI,which has the characteristics of simple operation,strong visualization ability and strong signal processing ability.The properties and implementation methods of different controls are researched,and the program design of main interface,display area,signal generation and storage,time domain and frequency domain analysis are designed.(3)The C-MEX program is designed that can be called by MATLAB,so as to obtain the data uploaded by the USB interface in MATLAB,and display the acquired data through the GUI.(4)Research and solve the problem of data transfer between different GUI,realize the functions of multiple GUI interfaces running at the same time and data sharing,finally complete the packaging and encapsulation of software.