Research Of Embedded Non-linear Junction Detector Based On Android

Currently, in order to effectively safeguard public safety, the prevention of all kinds ofviolence could harm peace and stability of the occurrence, the field of security more inclined touse the new technology, new products to strengthen security measures to reinforce securityfortress. In particular, in all kinds of security, based on harmonic radar designed to detectconcealed targets, the investigation of prohibited belongings nonlinear junction detector(Non-Linear Junction Detector, NLJD) is becoming a widely used tool for the security gate one.The so-called non-linear junction target both semiconductor electronic equipmentcontaining PN junction, but also contains a metal object metal junction. The moment, the mainwork of domestic non-linear detector in the L-band (frequency range of1-2GHz), the shape ofsuch products targeting is larger than the standard. However, faced with an endless stream ofminiaturized electronic devices, gradually revealed the existence of the probe target blind, lowalarm sensitivity, interference and poor performance of many constraints cannot really meet theapplication to eliminate safety hazards and need outside perimeter. In order to solve thechallenging issues facing the L-band non-linear junction detector, the detector working bandgradual transition from L-band to S band (frequency range of2-4GHz). Contemporary,sophisticated localization S-band products are still uncommon, therefore, the development ofthe S-band non-linear junction detection devices have practical significance, the paper workthat is in such a context unfolded.In essence, S-Band is a non-linear junction detection device to detect non-linear junctiontarget-centric, computer technology-based embedded systems. The exploration mission isclosely related to the implementation of the fundamental transmitter module, receiver front-endharmonics and signal processing terminals and other components of the system are dedicatedperipherals. Therefore, this paper will rely on the correlation of hardware platforms, mainlyfrom the perspective of embedded systems, to the theory, methods, software engineering as aguide, the nonlinear knot detection devices around major software development work, chooseSystem in the implementation of some of the key techniques, methods as the key concern. The main work is as follows:First, from a macro framework map out the system puts forward a non-linear junctiondetector system architecture design to guide the paper work. Non-linear junction detector bymeans of embedded computer systems and the implementation of the two components, selectthe Android4.0operating system and ARM Cortex-A hardware platform to achieve non-linearjunction detection integration and collaboration of each module, embodies the software andhardware interdependence collaborative design of embedded features.Second, non-linear junction detector system in the embedded software infrastructure layer,depending on the hardware platform features of the system core software selection,configuration, tailoring and compile to open the way to achieve a customized Android portingto ARM hardware platform. After the paper describes the basic components of the embeddedsystem software platform, in the establishment of a U-boot boot loader, adaptive croppingconfigured version of Linux3.0.8kernel Samsung, YAFFS2mount root file system, byprogramming operation Android4.0successfully deployed to OK210-A development board,which provides the underlying support for the system software development, commissioningand operation.Third, the hardware abstraction layer embedded nonlinear knot detection system using JNItechnology between embedded computer systems and peripherals hardware implementation ofdetection based on the on-board RS232serial communications solutions. Papers follow callunmanaged code in Android applications, technical processes, designed to open and close withthe serial method declarations and Serial Port class local calls, local analysis method javasgenerate the required output header file (.h), C function prototype definition is based on thelocal method to achieve the source is given, and finally got the dynamic link library compiledcontain native method implementation. Above work nonlinear knot detection device betweenAndroid and fundamental level transmitter module, receiver module provides harmonicenabling mechanism for control commands via the serial transmission.Finally, the user interface layer embedded non-linear junction detector system based onAndroid UI framework that focuses on the construction of high-level non-linear junctiondetector application specific tasks. Thesis plan and implement the UI interface detection system,in complying with Android UI under the principle of a single-threaded model, are given by way of case specific method utilizes mechanisms Handler UI thread-safe operations.Thesis work is an integral part of the "non-linear junction detection device development"projects; project results ultimately materialized an S-band non-linear junction detector.Compared with the L-band non-linear junction detector, the device effectively increases thearea of nonlinear scattering knot goal in improving the detection range and precision, whileenhancing the stability and reliability, further reducing false alarms, leak Police incidentoccurred, has practical value.