Sub-Ghz-based Traffic Monitor System Device Design

As urbanization shifts to modernization and intelligence,urban security has always been a key concern to the government and society.So far,China’s video surveillance system has already developed to a high level,but illegal crimes still occur from time to time.It is understood that it is most criminals’ common means to use private cars and shun video surveillance through decks and other means.To solve this social problem and improve the convenience of traffic management,this thesis elaborates on a solution to monitor the vehicle through wireless signals,and designs a traffic monitoring system based on Sub-GHz technology.The design has realizes the receiving and processing functions of most brand car key signalsThe monitoring system adopts STM32F407 processor as the central controller and data processing center,and uses FreeRTOS as the embedded operating system to support,through which the front-end data can be processed and be capable of executing network functions.MAX 1471 is used as the receiver’s main chip,which has complete custom RF components,ASK and FSK decoding modules.This paper firstly analyzes and introduces ARM and its peripheral hardware devices in detail.Then it illustrates the hardware design of the system,including scheme selection,RF signal processing,baseband signal processing,solutions to special and difficult problems.Finally,the software design of the front and rear ends is explained and the methods of signal collection,automotive wireless code,LAN technology are analyzed in detail.