The Design And Implementation Of The Handheld Positioning Device

With the development of science and technology,GPS(Global Position System) applications also continues to expand,especially in Europe and the United States and other developed countries,GPS technology has been widely used,GPS navigation,field exploration,scientific research and other fields.The current development of domestic GSM technology is very mature,convenient in use,many companies are also active combination of two technologies,hoping to be their application gradually into people's daily lives.Under these conditions,this paper presents the development of portable handheld positioning device,mainly use in security personnel and vehicles,special target tracking,emergency help,special occa-sions,group management,and so on.In this paper,base on the needs analysis of the positioning decices,reading and finding a great deal of relevant literature and proposed the software and hardware design plan,and verify this plan's validity in the simulation environment.First,analyae the background of technology and needs for the positioning devices,deter- mine the functions of devices and the technical means to achieve these functions.AT89C52 single-chip microcomputer is the master chip in devices to co-ordinate and control the work of each module;the company of Swiss u-blox's LEA-5S module is used to receive GPS satellite data,the company of WAVE COM's Wismo Quik Q2406B module is used to receive commands and send location infor- mation and feedback information to the user,and use for calling and so on.Master chip with GPS and GSM(Global System For Mobile Communication) modular communicate through the serial port; Human-computer interaction design liquid crystal display,button,indicator light; informations store through the SIM card;software design is the focus in the paper,the design approach of software use for modular,set up GPS information processing module,GSM infor- mation processing module and the information processing Human-Computer Interaction module;GPS consult NEMA0183 protocol to receive information,GPS configuration information refer to the company u-blox specific UBX protocol,use the AT(Attention) command to control the receipt and processing of short message command and control other functions for GSM module;at the same time in this paper design the format for user to use to send short message commands,set SIM card storage space and so on.This topics in the design basis,build hardware platform,and on this platform programming and debugging software with the Medwin emulators,realizes the main function of the decices.