The Design Of USB Interface System Based On The Internet Of Things

With the continuous development of communication technology, network technology, chip technology and other technologies, Internet of Things, once again, as an information technology revolution after Internet, microcomputers, smart phones, multimedia technologies, has become the strategy commanding point of a new-round economic and IT development. However, a series of problems in Internet of Things such as its large amount of data, wide variety of interfaces and non-uniformity of interfaces give rise to many problems in the process of its rapid development. Based on tackling the existing problem of non-uniformity of interfaces, the author managed to explore a type of interface which is able to meet the conditions as multiple standards of interface, large transmission speed range, low power and low cost. This type of interface is especially efficient in ensuring itself and other kinds of interface to be converted into the same kind, and it is good in compatibility, simple in future upgrades and long in transmission distance. A design scheme is proposed to use USB interface to connect interfaces of Internet of Things. It features fast transmission speed and long transmission distance, which enables it to solve problems like large amount of data and long transmission speed better, thus it is of good innovation. Gradually refined sub-module design method is selected. Aiming at current problems like wide range of data, a scheme is proposed to improve the problem of non-uniformity of interfaces of Internet of Things, that is to combine USB interface technology with Altera Corporation’s Cyclone II series FPGA chip technology, which features short development time, stable control performance, sufficient input and output interfaces and flexible design. VHDL hardware description language is used to achieve the design of each function of this system, including control module of USB interface chip, and preprocessing module, recognition module, encoding process module, analysis module and display module of data of Internet of Things. The main functions of USB interface subsystem are:(1) implementation of basic USB data transfer capability and efficient and correct transmission of all kinds of high-speed and low-speed data;(2) correct tab to data at the transmitting end and package of data for the first time;(3) correct extraction and analysis to data at the receiving end.The main research work of the design is mainly embodied in the following sections: First, studies conducted to technology of Internet of Things, USB technology and FPGA technology are a basis to process data of Internet of Things by FPGA and design the control parts of USB data transmission, among which the data processing section includes data processing of all kinds of data, data recognition, data classification, data packing, packing and unpacking of USB data, and the control part is to transfer data via timing sequence and USB controllers. Second, C language is used to write chip firmware drive program on the USB interface chip configurations, and the program is downloaded to USB chip interface via specified downloading line. Third, in order to achieve simulation in of USB interface transmitting system in function, ModelSim functional simulation is designed and used. Fourth, VHDL hardware description language is used to write hardware codes, which are compiled and debugged on integrated software. Then the program is downloaded to the FPGA chip, and the simulation results show that the system is available, thus the communication purpose of the design scheme and system is completed. The thesis provides reference for further study of future data transmitting system of Internet of Things.