Research And Design Of Data Acquisition System Based On USB Interface

The thesis is mainly concerned with the design process of data acquisition system that is base on Universal Serial Bus (USB). The design scheme, developing method and developing process of a suit of data acquisition system used with Philips' PDIUSBD12 and Atmel's AT89S52 are expatiated. In addition, the paper also gives the material realization scheme.At first, the paper introduces the protocol of USB bus and the WDM windows driver model in brief, and then discusses the design of data acquisition system, which includes hardware design, firmware design and device driver, application program development, in details.In hardware segment, data acquisition module and communication module base on USB are represented. The AD convert circuit and the method of using FIFO to achieve high speed data share between data acquisition module and communication module are given in the data acquisition part. The communication module introduces how the MSC51 singlechip works together with the Philips' PDIUSBD12.In software segment, introductions about singlechip firmware, PC device driver and application program are presented at length. The function of firmware includes resolution of commands that come from the host computer, data acquisition, pack the collection data according to the protocol of USB and send the package to the host computer. The device driver is used as the interface between low-level hardware and application program, and based on WDM module. It takes IRP as the carrier of message transmission and the development tool is DriverStudio. It attains the function of mutual communication with the system's low-level core. Application program that can communicate with the USB data acquisition card was built by VC6.0. Though the interface looks like simple, the program can accomplish the basic operations such as collection data display, data save. It also can be extended in functions.