Design Of Virtual Instrument System Based On Android System

Test instruments have been developed for a few years, which has played a huge role in the economic development. With the advances in science and technology, Test equipments develope from traditional equipments to digital equipments. With the development of computer science technology, virtual instruments have been raised and achieved. Virtual instruments fully integrate computer technology, bus technology and digital technology, promoting the development of test equipments. Along with the popularity of the Android system devices, virtual instruments which were originally implemented on the desktop can be implemented in mobile platform. Miniaturized chip can make DAQ devices easier to carry. Software system can be designed more user-friendly. Android-based virtual instruments meet the users’ demand in harsh conditions.Combining the PC virtual instrument system architecture with the unique Android system terminal interaction, we propose a virtual oscilloscope system design based on Android system. We focus on data acquisition driver layer implement in the Android system, interactive UI design on Android devices and oscilloscope functions implement on Android system. We have also established a USB connection from Android devices to data acquisition.Analyze the current status of test equipment development, particularly the status of virtual instrument based on the Android system from research institutions and enterprises.Combining with the PC virtual instrument system architecture and shortcomings of traditional instruments, we propose a framework of virtual oscilloscope design based on the Android system. We analyze the design project of the data acquisition card, driver layer and application layer in detail.USB firmware development and the implementation of driver layer are described in detail, which relate to the USB firmware descriptor and specific descriptors configuration. We also implement digital signal processing function modules in our software system.Because of touch screens and the screen size on the Android device, we design a drawer style interface. Taking advantage of thread and controls in the Android system, we implement user select listener, data read and data graphically in application layer.Building hardware and software testing environment, we test the virtual oscilloscope software system implementation in performance and functionality.