4、ndsoftwareprogramcode.AT89C52isthecontrolcoreofthesystem.The Hallelementcanhelptomeasurethedistance,When the bus atacertain site,MCU control the ISD4004voicechip toBroadcast asite,atthesametimetheLED digitaltube willshowthe site.Thehardwaredesignofwholesystermincludesdisplaycircuit,
5、keyboardcircuit,powersupplycircuitanddistance detection circuit.Thissystemgreatlyimprovesthe accuracyandreliability of busstations, and improvesthequalityofservice of the publictransportsystem.Keywords:Automatic stopannouncementsystem,AT89C52,ISD4004chip,The hallelement,LEDdisplayII目