Design And Implementation On Wireless And Variable Message Display System

The road traffic accident is "the first public nuisance of modern society." Numbers of casualties in highway traffic accident hold the very great proportion in the entire road traffic accident.As one of highway traffic information systems,the variable message display system plays an active role in the prevention of highway traffic accidents.Nowadays,message display systems are mostly based on RS-232 or RS-485. Although very economical they are,their application is limited in very great degree by the wired data transmission way.To solve the problem,the data transmission would carry on through the GSM network in this paper,in other words,the GSM engine module would be combined with the traditional single chip system,and realize wireless data transmission through the RS-232 interface.This thesis states detailedly the designing process of wireless variable message display system.It studies the possibility of controlling LED display screen remotely by using SMS messages as the medium to transmit data,and shows the design of controlling LED display screen remotely by using the PC,TC35i module and AT89C52 single chip, and introduces the hardware composition and the designing process of soft wares of wireless-controlling LED display screen in detail.Wireless and Variable Message Display System conjuncts serial port of PC with TC35i module,and initializes TC35i module and completes the functions of message receiving and sending through AT command,meanwhile,controlling and data communicating between receiver and TC35i module are completed by AT89C52 single-chip,and then conjuncts driving circuit with LED Display Screen and displays characters.Practice shows that this designing concept has solved the limitations of the wired transmission,and is advantageous in multi-machine system consisting of the PC and single-chip through the serial interface,thus widening the application sphere of display screen and having some applicable value.