Based On Usb Technology Embedded Equipment Design And Realization

With the development of information technology and electronic technology, computers and other electronic devices also develop fast and be applied widely. Data acquisition technology is used in the science research field and lots of manufacture occasion which require every parameter of data acquisition higher and higher. Traditional communications style is strongly restricted the development of data acquisition devices because of slow transmitting rate, weak antigambling ability,inconvenient installation and so on.New generation Universal Serial Bus has the advantages of small transmission line,quick transmitting rate,sustaining hot-plug and pull,easy extensibility and so on which solved the problems of traditional communications style well. So Universal Serial Bus technology gains wide applications in the computer system and communications devices.Through the redesign and implementation of a USB peripheral of "Portable Drug Addicts Rapid Pupil Detector", this paper studies the design of a USB based video capture and LED brightness control system, from the aspect of both hardware and software. The main function of the peripheral of "Pupil Detector" is to capture a video from a man's left eye, which records the reaction on its pupil, when his right eye is stimulated by some specific light. The video is used by the host computer to conduct drug addiction analysis.Around the Acquisition of video capture technology and LED control system that based on the USB technology, the article discussed its basic components, system hardware, and software design and gave a detailed description of the USB interface as well as the principle part of the host's video collection, given related hardware and software design. For the previous generation of products that exist in the circuit design problems, the author has been redesigned the hardware and completed all software development independently. The development of the Linux device driver adopts user space mode method. It not only reduces difficulty in development but improve the driver's portability. As the host to use a portable battery-powered, in order to extend battery life, the issue of power consumption is taken into careful consideration in the choice of chips, hardware design and software designed.Finally, and the performance of the system was tested.Test results show that the system has good performance and stability. The video captured meets the requirement of the host. The design of this paper reaches the goal. The new peripheral saves power by 50%, not only extends battery life, but also improved stability of the whole system. Through the redesign of the peripheral, the author further masters USB technology, which also sets a foundation for the laboratory on this field. USB technology will be widely applied in the future and is valuable for further study.