步進(jìn)電機及單片機英文文獻(xiàn)及翻譯

第頁外文文獻(xiàn)：Knowledgeofthesteppermotor

Whatisasteppermotor：

Steppermotorisakindofelectricalpulsesintoangulardisplacementoftheimplementingagency.Popularlittlelesson:Whenthedriverreceivesasteppulsesignal,itwilldriveasteppermotortosetthedirectionofrotationatafixedangle(andthestepangle).Youcancontrolthenumberofpulsestocontroltheangulardisplacement,soastoachieveaccuratepositioningpurposes;thesametimeyoucancontrolthepulsefrequencytocontrolthemotorrotationspeedandacceleration,toachievespeedcontrolpurposes.

Whatkindsofsteppermotorsub-：

Inthreesteppermotors:permanentmagnet(PM),reactive(VR)andhybrid(HB)permanentmagnetstepperusuallytwo-phase,torque,andsmaller,stepangleof7.5degreesorthegeneral15degrees;reactionstepisgenerallythree-phase,canachievehightorqueoutput,stepangleof1.5degreesisgenerally,butthenoiseandvibrationarelarge.80countriesinEuropeandAmericahavebeeneliminated;hybridstepperisamixofpermanentmagnetandreactiveadvantages.Itconsistsoftwophasesandthefive-phase:two-phasestepangleof1.8degreeswhilethegeneralfive-phasestepangleof0.72degreesgenerally.ThemostwidelyusedStepperMotor.

Whatistokeepthetorque(HOLDINGTORQUE)Howmuchprecisionsteppermotor?Whetherthecumulative：

Thegeneralaccuracyofthesteppermotorstepangleof3-5%,andnotcumulative.

SteppermotortoallowtheminimumamountofsurfacetemperatureSteppermotortoallowtheminimumamountofsurfacetemperature：

Steppermotorcausesthemotortemperatureistoohighthefirstmagneticdemagnetization,resultinginlossoftorquedownevenfurther,sothemotorsurfacetemperatureshouldbethemaximumalloweddependingonthemotordemagnetizationofmagneticmaterialpoints;Generallyspeaking,themagneticdemagnetizationpointsareabove130degreesCelsius,andsomeevenashighas200degreesCelsius,sothesteppermotorsurfacetemperatureof80-90degreesCelsiusisnormal.

HowtodeterminethesteppermotordriverDCpowersupply：

A.Determinationofthevoltage

Hybridsteppingmotordriverpowersupplyvoltageisgenerallyawiderange(suchastheIM483supplyvoltageof12~48VDC),thesupplyvoltageisusuallybasedontheworkofthemotorspeedandresponsetotherequesttochoose.Ifthemotoroperatingspeedhigherorfasterresponsetotherequest,thenthevoltagevalueishigh,butnotethattheripplevoltagecannotexceedthemaximuminputvoltageofthedrive,oritmaydamagethedrive.

B.DeterminationofCurrent

PowersupplycurrentisgenerallybasedontheoutputphasecurrentdriveItodetermine.Ifalinearpowersupply,powersupplycurrentisgenerallypreferable1.1to1.3timestheI;ifweadopttheswitchingpowersupply,powersupplycurrentisgenerallypreferabletoI,1.5to2.0times.

Themaincharacteristicsofsteppingmotor：

Asteppermotordrivecanbeaddedoperatepulsedrivesignalmustbenopulsewhenthesteppermotoratrest,suchas

Ifaddingtheappropriatepulsesignal,itwilltoacertainangle(calledthestepangle)rotation.Rotationspeedandpulsefrequencyisproportionalto.

2Dragonstepanglesteppermotorversionis7.5degrees,360degreesaround,takes48pulsestocomplete.

3steppermotorhasinstantstartandrapidcessationofsuperiorcharacteristics.

Changethepulseoftheorderof4,youcaneasilychangethedirectionofrotation.

Therefore,thecurrentprinters,plotters,robotics,andsodevicesarethecoreofthesteppermotorasthedrivingforce.

Steppermotorcontrolexample

Weusefour-phaseunipolarsteppermotorasanexample.ThestructureshowninFigure1:

Fourfour-phasewindingleads(asopposedtophaseA1A2B1phasephaseB2)andtwopubliclines(tothepowerofpositive).Thewindingsofonephasetothepoweroftheground.Sothatthewindingswillbeinspired.Weusefour-phaseeight-beatcontrol,ie,1phase2phasealternatingturn,wouldenhanceresolution.0.9°perstepcanbetransferredtocontrolthemotorexcitationistransferredinorderasfollows:

Iftherequirementsofmotorreversal,thetransmissionexcitationsignalcanbereversed.2controlscheme

Controlsystemblockdiagramisasfollows

TheprogramusesAT89S51asthemaincontroldevice.ItiscompatiblewiththeAT89C51,butalsoincreasedtheSPIinterfaceandthewatchdogmodule,whichnotonlymakesthedebuggingprocessbecomeseasyandalsomorestable.Themicrocontrollerintheprogrammainlyforfieldsignalacquisitionandoperationofthesteppermotortocalculatethedirectionandspeedinformation.ThensenttotheCPLD.

CPLDwithEPM7128SLC84-15,EPM7128programmablelogicdeviceoflarge-scale,fortheALTERAcompany'sMAX7000family.Highimpedance,electricallyerasableandothercharacteristics,canbeusedforthe2500unit,theworkingvoltageof+5V.CPLDreceivesinformationsentfromthemicrocontrollerafterconvertedtothecorrespondingcontrolsignaloutputtothesteppermotordrive.Putthecontrolsignaldrivesthemotorwindingsaftertheinput,toachieveeffectivecontrolofthemotor.2.1Thehardwarestructureofthemotordrive

Motordriveusingthefollowingcircuit:

R1-R8inwhichtheresistancevalueof320Ω.R9-R12resistancevalue2.2KΩ.Q1-Q4asDarlingtonD401A,Q5-Q8fortheS8550.J1,J2andthesteppermotorconnectedtothesix-lead。Advantagesanddisadvantagesofsteppermotor

Advantages

1.Themotorrotationangleisproportionaltothenumberofpulses;

2.Whenthemotorstoppedwithamaximumtorque(whenthewindingexcitationtime);

3.Sincetheaccuracyofeachstepinthethreepercenttofivepercent,andtheerrorwillnotaccumulatetothenextstepandthushasbetterpositionalaccuracyandrepeatabilityofmovement;

4.Excellentresponsefromthestopandreverse;

5.Intheabsenceofbrush,highreliability,itjustdependsonthelifeofthemotorbearinglife;

6.Motorresponseonlydeterminedbythenumberofinputpulses,whichcanbeusedopenloopcontrol,whichmakesthemotorandcontrolstructurecanberelativelysimple

Systemcost

7.Justloaddirectlyconnectedtothemotorshaftcanalsobeextremelyslowsynchronousrotation.

8.Speed??isproportionaltothepulsefrequency,andthusarelativelywidespeedrange.

Shortcomings

1.Ifnotproperlycontrolledpronetoresonance;

2.Difficultoperationtoahigherspeed.

3.Difficulttoobtainhightorque

4.Thereisnoadvantageintermsofvolumeweight,lowenergyefficiency.

5.Overloadwilldestroythesynchronization,theworkwillbeissuedwhenhigh-speedvibrationandnoise.Steppermotordriverequirements

(1)toprovidefastriseandfallofcurrentspeed,thecurrentwaveformascloseaspossiblerectangle.

Fortheperiodendedwiththereleaseoftheloopcurrentflow,toreducethewindingendsofthebackelectromotiveforce,toacceleratethecurrentdecay.

(2)rhymewithhigherpowerandefficiency.

Steppermotordriver,whichisthecontrolpulsesignalemittedintotheangulardisplacementofthesteppermotor,or:thecontrolsystemsendsapulsesignaleachthroughthesteppermotordrivetorotateastepangle.Thatisthesteppermotorspeedisproportionaltothefrequencyandpulsesignals.Therefore,thefrequencycontrolpulsesignal,tobeprecisemotorspeedcontrol;controlthenumberofsteppulsestoconnectthemotoraccurately.Steppermotordrivetherearemany,weshouldtakeareasonablechoiceofpowerrequirementsofthedrive,thefollowingwereintroducedvarioustypesoftypicaldrive.

Thelatesttechnologicaldevelopments

Domesticandinternationalresearchonthesub-drivetechnologyisveryactive,high-performancesub-drivercircuitcanbebrokendownintothousandsorevenanysubdivision.Nowabletodocomplicatedcalculationstomakeafterthebreakdownofuniformstepangle,whichgreatlyimprovestheresolutionofsteppermotorpulses,reduceoreliminatethevibration,noiseandtorqueripple,thesteppermotorismore"classserver"feature.

Theactualroleofstepangle:intheabsenceofsub-drive,theuserselectadifferentnumberofphasesdependsmainlyonthesteppermotortomeettheirownrequirementsonthestepangle，Ifyouusethesub-drive,theusercanchangethedrivenumberofsegments,candramaticallychangetheactualstepanglesteppermotor'phases'ofchangeintheroleoftheactualstepangleisalmostnegligible.IntroductionofAT89C51DescriptionTheAT89C51isalow-power,high-performanceCMOS8-bitmicrocomputerwith4KbytesofFlashprogrammableanderasablereadonlymemory(PEROM).ThedeviceismanufacturedusingAtmel’shigh-densitynonvolatilememorytechnologyandiscompatiblewiththeindustry-standardMCS-51instructionsetandpinout.Theon-chipFlashallowstheprogrammemorytobereprogrammedin-systemorbyaconventionalnonvolatilememoryprogrammer.Bycombiningaversatile8-bitCPUwithFlashonamonolithicchip,theAtmelAT89C51isapowerfulmicrocomputerwhichprovidesahighly-flexibleandcost-effectivesolutiontomanyembeddedcontrolapplications.FunctioncharacteristicTheAT89C51providesthefollowingstandardfeatures:4KbytesofFlash,128bytesofRAM,32I/Olines,two16-bittimer/counters,afivevectortwo-levelinterruptarchitecture,afullduplexserialport,on-chiposcillatorandclockcircuitry.Inaddition,theAT89C51isdesignedwithstaticlogicforoperationdowntozerofrequencyandsupportstwosoftwareselectablepowersavingmodes.TheIdleModestopstheCPUwhileallowingtheRAM,timer/counters,serialportandinterruptsystemtocontinuefunctioning.ThePower-downModesavestheRAMcontentsbutfreezestheoscillatordisablingallotherchipfunctionsuntilthenexthardwarereset.PinDescriptionVCC：Supplyvoltage.GND：Ground.Port0：Port0isan8-bitopen-drainbi-directionalI/Oport.Asanoutputport,eachpincansinkeightTTLinputs.When1sarewrittentoport0pins,thepinscanbeusedashighimpedanceinputs.Port0mayalsobeconfiguredtobethemultiplexedloworderaddress/databusduringaccessestoexternalprogramanddatamemory.InthismodeP0hasinternalpullups.Port0alsoreceivesthecodebytesduringFlashprogramming,andoutputsthecodebytesduringprogramverification.Externalpullupsarerequiredduringprogramverification.Port1Port1isan8-bitbi-directionalI/Oportwithinternalpullups.ThePort1outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort1pinstheyarepulledhighbytheinternalpullupsandcanbeusedasinputs.Asinputs,Port1pinsthatareexternallybeingpulledlowwillsourcecurrent(IIL)becauseoftheinternalpullups.Port1alsoreceivesthelow-orderaddressbytesduringFlashprogrammingandverification.Port2Port2isan8-bitbi-directionalI/Oportwithinternalpullups.ThePort2outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort2pinstheyarepulledhighbytheinternalpullupsandcanbeusedasinputs.Asinputs,Port2pinsthatareexternallybeingpulledlowwillsourcecurrent,becauseoftheinternalpullups.Port2emitsthehigh-orderaddressbyteduringfetchesfromexternalprogrammemoryandduringaccessestoexternaldatamemorythatuse16-bitaddresses.Inthisapplication,itusesstronginternalpullupswhenemitting1s.Duringaccessestoexternaldatamemorythatuse8-bitaddresses,Port2emitsthecontentsoftheP2SpecialFunctionRegister.Port2alsoreceivesthehigh-orderaddressbitsandsomecontrolsignalsduringFlashprogrammingandverification.Port3Port3isan8-bitbi-directionalI/Oportwithinternalpullups.ThePort3outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort3pinstheyarepulledhighbytheinternalpullupsandcanbeusedasinputs.Asinputs,Port3pinsthatareexternallybeingpulledlowwillsourcecurrent(IIL)becauseofthepullups.Port3alsoservesthefunctionsofvariousspecialfeaturesoftheAT89C51aslistedbelow:Port3alsoreceivessomecontrolsignalsforFlashprogrammingandverification.RSTResetinput.Ahighonthispinfortwomachinecycleswhiletheoscillatorisrunningresetsthedevice.ALE/PROGAddressLatchEnableoutputpulseforlatchingthelowbyteoftheaddressduringaccessestoexternalmemory.Thispinisalsotheprogrampulseinput(PROG)duringFlashprogramming.InnormaloperationALEisemittedataconstantrateof1/6theoscillatorfrequency,andmaybeusedforexternaltimingorclockingpurposes.Note,however,thatoneALEpulseisskippedduringeachaccesstoexternalDataMemory.Ifdesired,ALEoperationcanbedisabledbysettingbit0ofSFRlocation8EH.Withthebitset,ALEisactiveonlyduringaMOVXorMOVCinstruction.Otherwise,thepinisweaklypulledhigh.SettingtheALE-disablebithasnoeffectifthemicrocontrollerisinexternalexecutionmode.PSENProgramStoreEnableisthereadstrobetoexternalprogrammemory.WhentheAT89C51isexecutingcodefromexternalprogrammemory,PSENisactivatedtwiceeachmachinecycle,exceptthattwoPSENactivationsareskippedduringeachaccesstoexternaldatamemory.EA/VPPExternalAccessEnable.EAmustbestrappedtoGNDinordertoenablethedevicetofetchcodefromexternalprogrammemorylocationsstartingat0000HuptoFFFFH.Note,however,thatiflockbit1isprogrammed,EAwillbeinternallylatchedonreset.EAshouldbestrappedtoVCCforinternalprogramexecutions.Thispinalsoreceivesthe12-voltprogrammingenablevoltage(VPP)duringFlashprogramming,forpartsthatrequire12-voltVPP.XTAL1Inputtotheinvertingoscillatoramplifierandinputtotheinternalclockoperatingcircuit.XTAL2Outputfromtheinvertingoscillatoramplifier.OscillatorCharacteristicsXTAL1andXTAL2aretheinputandoutput,respectively,ofaninvertingamplifierwhichcanbeconfiguredforuseasanon-chiposcillator,asshowninFigure1.Eitheraquartzcrystalorceramicresonatormaybeused.Todrivethedevicefromanexternalclocksource,XTAL2shouldbeleftunconnectedwhileXTAL1isdrivenasshowninFigure2.Therearenorequirementsonthedutycycleoftheexternalclocksignal,sincetheinputtotheinternalclockingcircuitryisthroughadivide-by-twoflip-flop,butminimumandmaximumvoltagehighandlowtimespecificationsmustbeobserved.Figure1.OscillatorConnectionsFigure2.ExternalClockDriveConfigurationIdleModeInidlemode,theCPUputsitselftosleepwhilealltheonchipperipheralsremainactive.Themodeisinvokedbysoftware.Thecontentoftheon-chipRAMandallthespecialfunctionsregistersremainunchangedduringthismode.Theidlemodecanbeterminatedbyanyenabledinterruptorbyahardwarereset.Itshouldbenotedthatwhenidleisterminatedbyahardwarereset,thedevicenormallyresumesprogramexecution,fromwhereitleftoff,uptotwomachinecyclesbeforetheinternalresetalgorithmtakescontrol.On-chiphardwareinhibitsaccesstointernalRAMinthisevent,butaccesstotheportpinsisnotinhibited.ToeliminatethepossibilityofanunexpectedwritetoaportpinwhenIdleisterminatedbyreset,theinstructionfollowingtheonethatinvokesIdleshouldnotbeonethatwritestoaportpinortoexternalmemory.Power-downModeInthepower-downmode,theoscillatorisstopped,andtheinstructionthatinvokespower-downisthelastinstructionexecuted.Theon-chipRAMandSpecialFunctionRegistersretaintheirvaluesuntilthepower-downmodeisterminated.Theonlyexitfrompower-downisahardwarereset.ResetredefinestheSFRsbutdoesnotchangetheon-chipRAM.TheresetshouldnotbeactivatedbeforeVCCisrestoredtoitsnormaloperatinglevelandmustbeheldactivelongenoughtoallowtheoscillatortorestartandstabilize.中文譯文：步進(jìn)電機的知識什么是步進(jìn)電機：步進(jìn)電機是一種把電脈沖轉(zhuǎn)化為角位移的執(zhí)行機構(gòu)。通俗的說：當(dāng)驅(qū)動程序收到一個步進(jìn)脈沖信號，將驅(qū)動步進(jìn)電機軸旋轉(zhuǎn)一個固定的角度（步進(jìn)角）。您可以通過控制脈沖個數(shù)來控制角位移，從而達(dá)到準(zhǔn)確定位的目的;同時，你可以通過控制脈沖頻率來控制電機的旋轉(zhuǎn)速度和加速度，實現(xiàn)速度控制的目的。步進(jìn)電機的種類：步進(jìn)電機分為三種：永磁式（PM），反應(yīng)式（VR）和混合式（HR）永磁式步進(jìn)電機一般為兩相，轉(zhuǎn)矩和體積較小，步進(jìn)角一步7.5度或15度;反應(yīng)式一般有三相可以實現(xiàn)大轉(zhuǎn)矩輸出，步進(jìn)角一般是1.5度，但噪聲和振動大。在歐洲和美洲80個國家已被淘汰;混合式步進(jìn)是混合了永磁式和反應(yīng)的優(yōu)勢。它由兩相和五相：一般兩相的步距角是1.8度，而的五相步距角為0.72度。是使用最廣泛的的步進(jìn)電機。步進(jìn)電機允許的最高表面溫度步進(jìn)電機溫度過高首先會的磁性材料退磁，導(dǎo)致轉(zhuǎn)矩降低甚至失步，電機表面溫度允許的最大值取決于的磁性材料退磁點;一般來說，磁性材料退磁點在攝氏130度以上有些材料甚至高達(dá)攝氏200度高，所以步進(jìn)電機表面溫度在攝氏80-90度是正常的。步進(jìn)電機精度為多少？是否累積一般步進(jìn)電機的精度為步進(jìn)角的3-5%，且不累積如何確定步進(jìn)電機驅(qū)動器直流電源A.電壓確定混合式步進(jìn)電機驅(qū)動器的電源電壓范圍較廣（比如IM483的供電電壓12?48VDC），電源電壓通常根據(jù)電機的轉(zhuǎn)速和響應(yīng)要求來選擇。如果要求較快的運行速度較高的響應(yīng)速度就選用較高的電壓，但注意電源電壓的峰值不能超過驅(qū)動器的最大輸入電壓，否則可能會損壞驅(qū)動器。B.電流確定電源電流一般根據(jù)輸出相電流I來確定。如果采用線性電源，電源電流一般可取I的1.1?1.3倍;如果采用開關(guān)電源，電源電流一般可取I的1.5?2.0倍。步進(jìn)電機的主要特性在步進(jìn)電機關(guān)機時要確保沒有脈沖信號，當(dāng)電機運行時如果加入適當(dāng)?shù)拿}沖信號，它會轉(zhuǎn)過一定的角度（稱為步距角是）。轉(zhuǎn)速及脈沖頻率成正比。2龍式步進(jìn)電機步距角7.5度，旋轉(zhuǎn)360度，需要48個脈沖來完成。3步進(jìn)電機具有快速啟動和停止的優(yōu)良特性。4只要改變脈沖，可以很容易地改變電機軸旋轉(zhuǎn)的方向。因此，目前的打印機，繪圖儀，機器人設(shè)備以步進(jìn)電機作為動力核心。步進(jìn)電機控制的例子我們以四相單極步進(jìn)電機為例：四個相繞組引出四個相和兩個公共線（連接到正極）。一相接地。會被激發(fā)，。我們使用四相八拍控制，即第1階段第2階段交替反過來，會提高分辨率。步距角0.9°，可以轉(zhuǎn)移到控制電機勵磁是為了轉(zhuǎn)移如下：如果電機反轉(zhuǎn)的要求，傳輸?shù)募钚盘柨梢阅孓D(zhuǎn)的。2控制方案控制系統(tǒng)框圖如下該方案采用AT89S51的主要控制裝置。它是及AT89C51兼容，但也增加了SPI接口和看門狗模塊，這不僅使調(diào)試變得更容易，也更穩(wěn)定。單片機程序主要用于現(xiàn)場信號的采集和通過步進(jìn)電機的運轉(zhuǎn)來計算的方向和速度信息。然后將信息發(fā)送到CPLD。CPLD使用EPM7128SLC84-15，ALTERA公司的MAX7000系列可編程邏輯器件EPM7128。具有高阻抗，電可擦除等特點，可用單位數(shù)為2500單位，工作電壓+5VCPLD接收脈沖后轉(zhuǎn)換為相應(yīng)的控制信號輸出到步進(jìn)電機驅(qū)動器，從微控制器發(fā)送的信息。輸入后把控制信號發(fā)送到驅(qū)動電機繞組，以達(dá)到有效控制電機的目的。2.1為電機驅(qū)動器的硬件結(jié)構(gòu)電機驅(qū)動器通過下面的電路來實現(xiàn)：R1?R8的電阻值為320Ω。R9-R12的電阻值為2.2KΩ。Q1?Q4作為達(dá)林頓401A，Q5-Q8為S8550。J1，J2和步進(jìn)電機連接到六個接口。步進(jìn)電機優(yōu)點和缺點優(yōu)勢1。電機的旋轉(zhuǎn)角度及脈沖數(shù)成正比;2。當(dāng)電機停轉(zhuǎn)為最大轉(zhuǎn)矩（當(dāng)繞組勵磁時）;3。由于每一步準(zhǔn)確度為百分之三到五，而且誤差不會累積到下一步，因而具有更好定位精度和重復(fù)定位精度;4。優(yōu)良的啟動和制動特性_;5。沒有電刷，可靠性高，電機的壽命只是取決于電機軸承;6。電機_僅由輸入脈沖數(shù)決定，可用于開環(huán)控制，這使得電機和控制結(jié)構(gòu)確定相對簡單系統(tǒng)成本7。只是負(fù)載直接連接到電機軸也可以極其緩慢旋轉(zhuǎn)8。速度及的脈沖頻率成正比，因此，有相對較寬的調(diào)速范圍缺點1。如果沒有適當(dāng)?shù)目刂?，容易共?2。高速操作難度較大3。難以獲得大轉(zhuǎn)矩4。沒有體積小，重量輕，能耗低，效率高等方面優(yōu)勢5。過載時會破壞同步性，工作時會發(fā)出時較大的振動和噪音步進(jìn)電機驅(qū)動要求（1）為了滿足速度迅速上升或下降的要求，波形應(yīng)當(dāng)盡可能接近矩形以釋放回路電流流，繞組兩端的反電動勢，加速電流衰減（2）具有較高功率和效率步進(jìn)電機驅(qū)動器，把輸入的脈沖信號轉(zhuǎn)化為角位移，每當(dāng)控制系統(tǒng)發(fā)出一個脈沖信號，步進(jìn)電機驅(qū)動就旋轉(zhuǎn)一個步距角，步進(jìn)電機的速度及的脈沖信號頻率成正比，因此，通過控制脈沖信號頻率，就可以精確控制電機轉(zhuǎn)速步進(jìn)脈沖數(shù)決定準(zhǔn)確連接為電機步進(jìn)電機驅(qū)動器有很多，我們應(yīng)該根據(jù)功率采取的合理的方式選擇驅(qū)動器最新的技術(shù)發(fā)展國內(nèi)和國際上對于驅(qū)動技術(shù)的研究十分活躍，高性能子驅(qū)動電路可以細(xì)分成幾千部分甚至任意細(xì)分，現(xiàn)在已經(jīng)能夠做到通過復(fù)雜的計算統(tǒng)一步距角，大大提高了步進(jìn)電機的脈沖分辨率，減少或消除振動，噪聲和轉(zhuǎn)矩波動，步進(jìn)電機有了更多“類伺服”功能實際作用：步距角細(xì)分驅(qū)動器出現(xiàn)之前，用戶需要選擇不同的相來獲取不同的步進(jìn)電機步距角，以滿足自己的要求，如果使用細(xì)分驅(qū)動器，用戶可以通過更改驅(qū)動器號段，來改變實際的步距角，相數(shù)對實際步距角的作用幾乎可以忽略不計AT89C51的介紹描述AT89C51是一個擁有4K字節(jié)FLASH編程功能和可擦除只讀儲存器的低功耗，高性能CMOS8位微機（PEROM）。該設(shè)備是采用Atmel的高密度非易失性內(nèi)存技術(shù)并及工業(yè)標(biāo)準(zhǔn)的的MCS-51指令集和引腳兼容。芯片上的Flash允許程序存儲器通過系統(tǒng)或由傳統(tǒng)的非易失性存儲器編程重新編程。通過把一個多功能8位CPU及一個單一的芯片上的Flash相結(jié)合的，Atmel的AT89C51是一個功能強大微型計算機為許多嵌入式控制程序提供了高度靈活和成本效益的解決方案。功能特點AT89C51具有以下功能：4K字節(jié)的Flash，128字節(jié)RAM，32I/O口，兩個16位定時器/計數(shù)器，一個五向量2級中斷機構(gòu)，一個全雙工串行口，芯片振蕩器和時鐘電路。此外，AT89C51支持頻率為0的靜態(tài)邏輯運算，并支持兩種節(jié)電模式?？臻e模式時CP