DesignoftheTemperatureControlSystemBasedonAT89C51ABSTRACTTheprincipleandfunctionsofthetemperaturecontrolsystembasedonmicrocontrollerAT89C51arestudied,andthetemperaturemeasurementunitconsistsofthe1-WirebusdigitaltemperaturesensorDS18B20。Thesystemcanbeexpectedtodetectthepresettemperature,displaytimeandsavemonitoringdata。Analarmwillbegivenbysystemifthetemperatureexceedstheupperandlowerlimitvalueofthetemperaturewhichcanbesetdiscretionarilyandthenautomaticcontrolisachieved,thusthetemperatureisachievedmonitoringintelligentlywithinacertainrange.Basingonprincipleofthesystem,itiseasytomakeavarietyofothernon-linearcontrolsystemssolongasthesoftwaredesignisreasonablychanged.Thesystemhasbeenprovedtobeaccurate,reliableandsatisfiedthroughfieldpractice。KEYWORDS:AT89C51；microcontroller;DS18B20;temperature1INTRODUCTIONTemperatureisaveryimportantparameterinhumanlife。Inthemodernsociety,temperaturecontrol（TC)isnotonlyusedinindustrialproduction,butalsowidelyusedinotherfields。Withtheimprovementofthelifequality，wecanfindtheTCapplianceinhotels，factoriesandhomeaswell。AndthetrendthatTCwillbetterservethewholesociety，soitisofgreatsignificancetomeasureandcontrolthetemperature.BasedontheAT89C51andtemperaturesensorDS18B20,thissystemcontrolstheconditiontemperatureintelligently.Thetemperaturecanbesetdiscretionarilywithinacertainrange.ThesystemcanshowthetimeonLCD，andsavemonitoringdata;andautomaticallycontrolthetemperaturewhentheconditiontemperatureexceedstheupperandlowerlimitvalue.Bydoingsoitistokeepthetemperatureunchanged.Thesystemisofhighanti-jamming，highcontrolprecisionandflexibledesign；italsofitstheruggedenvironment.Itismainlyusedinpeople’slifetoimprovethequalityoftheworkandlife.Itisalsoversatile，sothatitcanbeconvenienttoextendtheuseofthesystem。Sothedesignisofprofoundimportance。Thegeneraldesign,hardwaredesignandsoftwaredesignofthesystemarecovered。1。1IntroductionThe8—bitAT89C51CHMOSmicrocontrollersaredesignedtohandlehigh—speedcalculationsandfastinput/outputoperations.MCS51microcontrollersare1typicallyusedforhigh—speedeventcontrolsystems.Commercialapplicationsincludemodems，motor-controlsystems，printers,photocopiers,airconditionercontrolsystems，diskdrives,andmedicalinstruments。TheautomotiveindustryuseMCS51microcontrollersinengine—controlsystems,airbags，suspensionsystems，andantilockbrakingsystems(ABS)。TheAT89C51isespeciallywellsuitedtoapplicationsthatbenefitfromitsprocessingspeedandenhancedon-chipperipheralfunctionsset,suchasautomotivepower—traincontrol，vehicledynamicsuspension,antilockbraking,andstabilitycontrolapplications.Becauseofthesecriticalapplications，themarketrequiresareliablecost—effectivecontrollerwithalowinterruptlatencyresponse,abilitytoservicethehighnumberoftimeandeventdrivenintegratedperipheralsneededinrealtimeapplications,andaCPUwithaboveaverageprocessingpowerinasinglepackage.Thefinancialandlegalriskofhavingdevicesthatoperateunpredictablyisveryhigh.Onceinthemarket，particularlyinmissioncriticalapplicationssuchasanautopilotoranti-lockbrakingsystem，mistakesarefinanciallyprohibitive.Redesigncostscanrunashighasa＄500K，muchmoreifthefixmeans2backannotatingitacrossaproductfamilythatsharethesamecoreand/orperipheraldesignflaw。Inaddition，fieldreplacementsofcomponentsisextremelyexpensive,asthedevicesaretypicallysealedinmoduleswithatotalvalueseveraltimesthatofth...
