Phidgets 1138 User manual

1138UserGuide
FromPhidgetsSupport
Contents
1GettingStarted
1.1CheckingtheContents
1.2ConnectingthePieces
1.3TestingUsingWindows
2000/XP/Vista/7
1.4RunningPhidgets
SampleProgram
1.4.1UpdatingDevice
Firmware
1.5TestingUsingMacOS
X
1.6UsingLinux
1.7UsingWindowsMobile/
CE5.0/CE6.0
2TechnicalDetails
2.1Ports
2.2Formulas
2.3OtherInterfacing
Alternatives
3API
4ProductHistory
GettingStarted
CheckingtheContents
Youshouldhavereceived:
Adifferentialgaspressuresensor
Asensorcable
InordertotestyournewPhidgetyouwillalsoneed:
APhidgetInterfaceKit8/8/8orPhidgetTextLCD
AUSBcable
ConnectingthePieces
1.ConnecttheGasPressureSensortooneofthe
AnalogInputsonthePhidgetInterfaceKit8/8/8using
thesensorcable.
2.ConnectthePhidgetInterfaceKittoyourPCusingthe
USBcable.
ProductsforUSBSensingandControl

TestingUsingWindows2000/XP/Vista/7
MakesureyouhavethecurrentversionofthePhidgetlibraryinstalledonyourPC.Ifyoudon't,followthesesteps:
1.GototheQuickDownloadssectionontheWindowspage
2.DownloadandrunthePhidget21Installer(32bit,or64bit,dependingonyoursystem)
3.Youshouldseethe iconontherighthandcorneroftheTaskBar.
RunningPhidgetsSampleProgram
Doubleclickingonthe iconloadsthePhidgetControlPanel;wewillusethisprogramtoensurethatyournewPhidget
worksproperly.
ThesourcecodefortheInterfaceKitfullsampleprogramcanbefoundinthequickdownloadssectionontheC#
LanguagePage.Ifyou'dliketoseeexamplesinotherlanguages,youcanvisitourLanguagespage.
UpdatingDeviceFirmware
Ifanentryinthislistisred,itmeansthefirmwareforthatdeviceisoutofdate.Doubleclickontheentrytobegiventhe
optionofupdatingthefirmware.Ifyouchoosenottoupdatethefirmware,youcanstillruntheexampleforthatdeviceafter
refusing.
DoubleClickonthe icontoactivatethePhidgetControl
PanelandmakesurethatthePhidgetInterfaceKit8/8/8is
properlyattachedtoyourPC.
1.DoubleClickonPhidgetInterfaceKit8/8/8inthe
PhidgetControlPaneltobringupInterfaceKitfulland
checkthattheboxlabelledAttachedcontainstheword
True.
2.MakesurethattheRatiometricboxisTicked.

3.Whenthesensorispluggedin,thevalueinAnalogIn
shouldbecloseto40.
4.Youcanadjusttheinputsensitivitybymovingthe
sliderpointer.
5.ClickontheSensorsbuttontobringuptheAdvanced
SensorForm.
1.IntheSensorboxoftheinputyouattachedthesensor
to,selectthe1138DifferentialGasPressureSensor
fromthedropdownmenu.
2.Thisisthepressuredifferentialbetweenthesensor
ports,measuredinPascalsandpoundspersquare
inch.
3.FormulausedtoconverttheanaloginputSensorValue
into.
TestingUsingMacOSX
1.GototheQuickDownloadssectionontheMacOSXpage
2.DownloadandrunthePhidgetOSXInstaller
3.ClickonSystemPreferences>>Phidgets(underOther)toactivatethePreferencePane
4.Makesurethattheisproperlyattached.
5.DoubleClickoninthePhidgetPreferencePanetobringuptheSampleprogram.Thisprogramwillfunctioninasimilar
wayastheWindowsversion.
UsingLinux
ForastepbystepguideongettingPhidgetsrunningonLinux,checktheLinuxpage.
UsingWindowsMobile/CE5.0/CE6.0
ForastepbystepguideongettingPhidgetsrunningonWindowsCE,checktheWindowsCEpage.
TechnicalDetails
TheDifferentialGasPressureSensorusesbipolarprocessingtoprovideanaccurate,highlevelanaloginputsignalthatis
proportionaltotheappliedpressure.Whenthesensorispluggedin,theSensorValueshoulddefaulttoabout40,which
correspondsto0kPabetweenthetwoports.
Ports
Thesensorcomeswithapositivetopportandanegativebottomport.Theseportshaveadiameterof2.79mmto3.30mm
(nominal3mm).
Takecautionwhenconnectingthepressureportsthissensoronlymeasuresapositivepressuredifferential,andyoucould
damagethesensorifyouconnectitinreverse.Ensurethattheupperportisalwaysatanequalorhigherpressurethanthe
lowerport.

Forhosing,werecommendusingpolyurethanetubing.Wehavehadgoodresults
with2.4mmIDtubingfromEmiplastics.com.Inimperialmeasurement,3/32”ID
tubingisequivalent.Thisisavailablethroughlaboratorysupplystoressuchas
ColeParmer.
Formulas
TheFormulatotranslateSensorValueintoPressureis:
Note:1.0kPa=0.145psi
OtherInterfacingAlternatives
Ifyouwantmaximumaccuracy,youcanusetheRawSensorValuepropertyfromthePhidgetInterfaceKit.Toadjustaformula,
substitute(SensorValue)with(RawSensorValue/4.095)IfthesensorisbeinginterfacedtoyourownAnalogtoDigital
ConverterandnotaPhidgetdevice,ourformulascanbemodifiedbyreplacing(SensorValue)with(Vin*200).Itisimportant
toconsiderthevoltagereferenceandinputvoltagerangeofyourADCforfullaccuracyandrange.
EachAnalogInputusesa3pin,0.100inchpitchlockingconnector.Picturedhereis
aplugwiththeconnectionslabelled.Theconnectorsarecommonlyavailablerefer
totheAnalogInputPrimerformanufacturerpartnumbers.
API
PhidgetanalogsensorsdonothavetheirownAPItheysimplyoutputavoltagethatisconvertedtoadigitalvalueand
accessedthroughthe"Sensor"propertiesandeventsonthePhidgetInterfaceKitAPI.Itisnotpossibletoprogrammatically
identifywhichsensorisattachedtotheAnalogInput.ToanInterfaceKit,everysensorlooksthesame.Yourapplicationwill
needtoapplyformulasfromthismanualtotheSensorValue(anintegerthatrangesfrom0to1000)toconvertitintothe
unitsofthequantitybeingmeasured.Forexample,thisishowyouwoulduseatemperaturesensorinaC#program:

//setuptheinterfacekitobject
InterfaceKitIFK=newInterfaceKit();

//linkthenewinterfacekitobjecttotheconnectedboard
IFK.open("localhost",5001);

//Getsensorvaluefromanaloginputzero
intsensorvalue=IFK.sensors[0].Value;

//ConvertsensorvalueintotemperatureindegreesCelsius
doubleroomtemp=Math.Round(((sensorvalue*0.22222)‐61.11),1);
SeethePhidgetInterfaceKitUserGuideformoreinformationontheAPIandadescriptionofourarchitecture.