VHR01-SPI

VHR01-SPITemperature&HumiditySensor-Relativehumidityandtemperaturesensor-相对温度和湿度传感器-Pre-calculatedtemperatureandhumidityreadout,noextracalculationneeded-预先计算的温度和湿度读出，无需额外计算-DewPointCalculationpossible-可以计算露点-FullyCalibrated,DigitalOutput-完全校准，数字输出-ExcellentLongTermStability-良好的长期稳定性-NoExtraComponentRequired-无需额外的组件-UltraLowPowerConsumption-超低功耗-FullyInterchangeable-完全可互换-SmallSize-尺寸小-AutomaticPowerDown-自动断电ProductSummery产品简介TheVHR01isaMCUbasedtemperatureandrelativehumiditysensormodule,comprisingaSPIinterface(mastermode)fordirecttemperatureandhumidityreadout.Thedigitaloutputispre-calculatedandnoextracalculationisrequired.Thesystemappliedtwosensorelements:NTCtypehighprecisiontemperaturesensorandaresistortyperelativehumiditysensorfromJapan.Withaveryuniqueandpatentedrelativehumiditycalculationalgorithm,thesystemcanassureaccuraterelativehumidityoutputthroughfinetunedtemperaturecompensationmechanism.Thusveryhighaccuratereadingofhumidityinthefulltemperaturerange(0-50C)canbeassured.该VHR01是一款基于温度和相对湿度的传感器模块，包括一个SPI接口（主模式）为直接的温度和湿度读出。数字输出是预先计算并无额外计算要求所必须的。改系统适用于两个传感器要素：NTC型高精度温度传感器和电阻式相对湿度传感器来自日本。有一个非常独特的专利和相对湿度的计算算法，该系统通过良好的温度调节补偿机制可以保证准确相对湿度输出。如此高精度读湿度在整个温度范围（0-50C）都可以保证。Applications适用产品-HVAC-HVAC产品-ConsumerProducts-消费类产品-WeatherStations-气象站-Humidifiers-加湿机-Dehumidifiers-抽湿机-TestandMeasurements-测试与测量-DataLogging-数据记录-WhiteGoods-白色家电VHR01-SPITemperature&HumiditySensorBlockDiagram1.ModulePerformanceSpecification模块性能规格Parameter参数Conditions条件Min最小值TypMax最大值Unit单位Humidity湿度Resolution分辨率1%Repeatability重复性1%AccuracyUncertainty精度不准确性Temperatureat0C–50Crange0+,-3+,-5%Interchangeability互换性FullyInterChangeableNonlinearity非线性12%Range范围Temperatureat0C–50Crange1898%ResponseTime响应时间63%slowlymoveair60SecondHysterisis重复性Non-condensate不结露12%LongTermStability长期稳定性Non-condensate2%/yrTemperature温度Resolution0.1˚CRepeatability0.10.2˚CRange-4070˚CAccuracy25+/-0.5+/-1.0˚CResponseTimedeltaT=1.060SVHR01-SPITemperature&HumiditySensor2.SensorInterface传感器接口Figure1:TypicalApplicationFigure2:ReduceIOUsageApplication2.1PowerPinsTheVHR01sensormodulerequiresavoltagesupplybetween2.0to5.5.Afterpower,thesensorneeds20mstocompleteitsinternalresetprocess.Afterresetfinished,thesensorwillmakeameasurementautomaticallyandiftheCSpinislow,thenthemeasureddatawillbeoutputautomatically.VHR01传感器模块需要2.0到5.5伏的电压供应。上电后，传感器需要20豪秒时间来完善其内部的重置过程。重置完成后，传感器会自动测量，若CS脚被拉低，测量数据会自动输出。Powerpinsshouldbedecoupledthrougha10-100nFcapacitor.Whereinthoseapplicationswithhighpowernoiseenvironment,itisstronglyrecommendedtousea10uFtantalumcapacitortoprotectthesensorfrominterferences.需通过一个10-100nF的电容退耦。凡是在高分贝噪音环境下的，强烈建议使用一个10uf钽电容，以保护传感器免被干扰。2.2SerialInterface串行接口TheserialinterfaceisoptimizedforconvenientreadingandreducingIOusage.ApplicationengineershouldbekeptinmindthecharacteristicsoftheIOpinsforapplicationswherecurrentconsumptioniscritical.串型接口是为方便读取和减少IO口用量进行的优化设计。应用工程师应牢记IO口的特性，对电流消耗有要求的场合是至关重要的Reset,INPUTpin,has50kpullupresisterconnectedinternally,thusduringnormalapplication,thepinshouldnotbetiedtolowunlessresetisreallyneeded.CS,INPUTpin,has100kpullup.Negativeedgewillwakeupthemoduleandsendthepreviousmeasureddatafirst,afterthattemperatureandhumiditymeasurementwilltakeplace.AslongasCSislow,measure-senddatacycleisrepeated.首先发送先前测到的数据，然后再开始温度和湿度的测量。只要CS拉低，测量，发数据的过程就会一直持续下去。SDATandSCK,OUTPUTpin,isinCMOSoutputmode.ThusforexternalMCUconnection,portsconnectingtothistwopinsshouldbeininputmodewithoutpullhighresistertoavoidhighcurrent.因此，对于外部的MCU连接，应该在输入模式，不用放入电阻以避免高电流2.2.1CSCSistoactivatethesensorandtriggerstosendoutthepreviousmeasuredtemperatureandhumidityvaluethroughSCKandSDATline.Afterdatasentout,aninternalADconvertcyclewillstartautomatically.IfCSlineiskeptlowafterADconvert,thenewmeasureddatawillbeoutputthroughthedatalinesuntilCSlinegoeshigh,whichistoterminatetheVHR01-SPITemperature&HumiditySensordataoutputandADconvertprocess.WhenCSishigh,thesystementerssleepmodetoreducepowerconsumption.通过拉低CS就会立刻将上次测量数据发送出来。数据发出后，一个将开始一个新温度湿度数据的测量。如果测量完成后CS还是低电平，新测量数据将会通过数据线输出直到CS线变高为止，即数据输出和AD转换过程终止。当CS高时，系统进入睡眠模式，以降低电力消耗。2.2.2SCKSCKistosynchronizethecommunicationbetweenMCUandthesensormodule.Itrunsataround1.5KHZspeed,whichshouldbeanidealspeedforbothhighandlowspeedMCUsystems.Oncealldataareout,SCKlinewillremainlow.SCK是使MCU和传感器模块间保持同步。它以1.5千赫的速度运行，这应是高速和低速单片机系统都理想的速度。一旦所有数据都出来了，SCK线将保持为低。2.2.3SDATSDATistotransferdatatoMCU.TheSDATlineisvalidafterSCKgoeshigh.Oncedataareallout,SDATlinewillremainlow.SDAT是将数据传输到微控制器。当SCK线变高时SDAT线才有效。当数据都出现后，SDAT线将保持为低。2.2.4ResetDuringnormaltime,Resetpinshouldbekepthigh.Incaseswhensensormodulecan’toutputdataafterCSlineissetlowfor50ms,thentheResetpinshouldbepulledlowfor15mstomakeaproperresetforthesensormoduletoreleasethesystemfromunknownstate.在正常期间，复位脚应该要保持高。如果当CS线拉低50ms后仍然不能有数据输出的话，可以拉低复位脚来复位系统。对高可靠性要求环境中建议使用此复位功能。3.BusTimingTostartadatareading,settheCSlinelowwillwakeupthesensormoduleandstarttotransferdatathroughthedataline.Thebustimingisspecifiedinthefollowingway:开始数据读取时，将CS线调低能激活传感器模块并通过数据线开始转换数据。数据时序以如下方式被指定的：Figure3:BustimingT1:10msNominalT2:900uST3:200mSOnceCSissethigh,sen