| Universal Serial Bus (USB) is one of the most important developments in PC peripheral interconnect technology since the introduction of serial and parallel ports in the early 1980's. The benefits of USB, such as ease of use, true plug and play, high performance, and reduced overall system cost, are just a few of the reasons this technology has gone from specification to product development in less than 2 years. USB can provide an excellent DAQ solution. USB give the system a very simple interface, good extension, and also make the system like more a pipeline. At the same time with the development of computer technology, the power of personal PC is becoming greater and greater and the technology of virtual instrument which is being develop at very fast speed has great foreground. It will become one new trend to apply USB and VI technology to measure instrument.The thesis discusses parameters of the alternating current measurement system based on USB. The structure, properties and application of the whole system are studied in details. The system is able to complete the data sample of 6 signals inputs, and has the ability to sample simultaneously of every signal input. The conversion is 12 bits. However, the outstanding character of it is the communication between MCU and PC based on USB technique, which make whole system more convenient and more flexible. The system is also a virtual device. This thesis introduces the design of USB interface, circuit of MCU, firmware in MCU, driver and user interface. At last provide some running results for reference.
|
PDF Full Text Request