基于数字温湿度传感器SHT11的温湿度测控系统-冯显英

《》271　20061SHT11TheTemperature/HumidityMeasurementandControlSystemBasedonDigitalTemperature/HumiditySensorSHT11　(山东大学机械工程学院,济南　250061)　:SHT11、,、。SHT11、AT89C51,,0.5°C,4%RH。、、。:　　　:TP212.9　　　　:AAbstract:Theoperationalprinciple,internalstructure,measurementresolutionandmeasurementrange,operationcommandandinterfacetimingofSHT11digitaltemperature/humiditysensorareintroduced.ByadoptingSHT11sensorandAT89C51microcontrolleratemperature/humiditymeasurementandcontrolsystemwascomposed.Thestrategiesofhardwarecompositionandsoftwaredesignwereproposed.Thepre-dictedindexesofthewholesystem,.ie.,measurementerroroftemperaturebetterthan0.5℃,measurementerrorofhumiditybetterthan4%RH,isaccomplished.Keywords:Temperature/humidity　Sensor　Singlechipcomputer　Measurementandcontrolsystem0　、、。,,。SHT11Sensiri-on,、,、、、。CMOS,、、。1　SHT11SHT11SensirioCMOSen©,、、A/D、,,、、、,1。SHT1114、12,12、8。0～100%RH,120.03%RH,-40℃～+123.8℃,14图1　SHT11内部结构框图Fig.1　InternalstuctureofSHT110.01℃。,OTP,,SHT11100%。、,,A/D、,,。2　SHT112.1　,SHT11,5,(03H)、(05H)、(07H)、(06H)59SHT11　,PROCESSAUTOMATIONINSTRUMENTATIONVo.l27No.1January2006(1EH)。DATASCKSCK。SHT11,“”,,SCKDATA,SCKDATA。,,SHT11。SCK,SHT11CRC,(MSB)(LSB)。,,ACK。CRC(x8+x5+x4),,,。CRC-8,LSBACK,。SHT11。,N=0000100100110001,2a、b、c。DATA,2SHT11,。图2　SHT11测量过程时序Fig.2　TimingofSHT11measuringprocedures2.2　SHT11,M,5V,14,:T=-40+0.01M。SHT11,N,12:RHL=(-4+0.0405N-2.8×10-6N2)%,,:RHT=RH+(T-25)(0.01+0.00008N)%,。3　SHT11AT89C51,SHT11。AtmelAT89C51、8CMOS,、,4k/(FPEROM),,、。、、,3。AT89C51SHT11,I/ODATASCK,DATA,VDDGND图3　温湿度测控系统电路原理图Fig.3　Principleofhumidityandtemperaturemeasurementcontrolsystem,,。,MAX813L“”,。1.6sAT89C51WDI,,MAX813L,。8LEDMAX7219,SPI,,I/O。,ISET。,5,1、1、、。、、、,。MC1413,,7I/O7。,。(AC-SSR)H220D15,,。,P1.6P1.7I/O,,60SHT11　,《》271　20061。,。4　AT89C51KEILC7.0C51,,,,,。,:①:“”,,T0、,。,。,,;②:,、,4,、2;图4　温湿度测量程序Fig.4　Flowchartofhumidityandtemperaturemeasurement③:,T0,T01(),50ms,20,1s。:“”、“”、,2,、1。T04;　　④:AT89C51,。5　SHT11,,,,。SHT11,。,,0.5℃,4%RH,。1　.ATMEL89[M].:,2002:25-40.2　.[M].:,2004:119-127.3　　,　,.I2CSHT11[J].,2004(3):50-54.4　,,.AT89C2051[J].,2004(1):21-23.5　Sensirion.SHT11[M],2003.　　收稿日期:2005-04-18。第一作者冯显英,男,1965年出生,1998年毕业于山东工业大学,获得博士学位,教授;主要研究领域为智能化精密检测技术、计算机数控(CNC)技术,已发表论文30余篇。(58)2　Florkowski,M..Waveletdenoisingofpartialdischargeimages.PropertiesandApplicationsofDielectricMaterials[C].Proceedingaofthe6thInternationalConferenceon,2000,1:459-462.3　W.Sweldens.Theliftingscheme:AConstructionofsecondgenerationwavelets[J].SIAMJournalofMathematicalAnalysis,1998,29(2).4　I.DaubechiesandW.Sweldens.Factoringwavelettransformsintoliftingsteps[J].FourierAna.lApplica.t,1998,4(3):247-269.5　RogerClaypoole,RichardBaraniuk,andRobertNowak.AdaptiveWaveletTransformsviaLifting[C].Acoustics,Speech,andSignalProcessing,1998.ICASSP’98.Proceedingsofthe1998IEEEInter-nationalConferenceon,1998,3:1513-1516.6　.[M].:,2002.7　ZhenLi,FengWu,ShipengLi,andEdwardDelp.Waveletvideocodingviaaspatiallyadaptiveliftingstructure.Acoustics,Speech,andSignalProcessing[C].Proceedings.(ICASSP’03).IEEEIn-ternationalConferenceon,2003,3:6-10.8　.[M].:,1994.9　,,,.[N].,2002,11:28-30.10　D.L.Donoho.De-NoisingbySoft-Thresholding[M].IEEETrans.OnIT,1995,41(3):612-627.　　收稿日期:2005-04-11。第一作者胡沁春,男,1976年生,现为湖南大学电气与信息工程学院在读博士研究生;主要研究方向为小波分析与应用、高速信号处理等。61SHT11　,