- When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System...
-
Upload
jonas-francis -
Category
Documents
-
view
213 -
download
0
Transcript of - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System...
![Page 1: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/1.jpg)
GPS-Whenpeopletalkabout"aGPS,"theyusuallymeanaGPS receiver.TheGlobal Positioning System(GPS)isactuallyaconstellationof27Earth-orbitingsatellites(24inoperationandthreeextrasincaseonefails).
--TheU.S.militarydevelopedandimplementedthissatellitenetworkasamilitarynavigationsystem,butsoonopenedituptoeverybodyelse.
--Eachofthese3,000-to4,000-poundsolar-poweredsatellitescirclestheglobeatabout12,000miles(19,300km),makingtwocompleterotationseveryday.Theorbitsarearrangedsothatatanytime,anywhereonEarth,thereareatleastfoursatellites"visible"inthesky.
![Page 2: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/2.jpg)
--AGPSreceiver'sjobistolocatefourormoreofthesesatellites,figureoutthedistancetoeach,andusethisinformationtodeduceitsownlocation.
--Thisoperationisbasedonasimplemathematicalprinciplecalledtrilateration.
--Trilaterationinthree-dimensionalspacecanbealittletricky,sowe'llstartwithanexplanationofsimpletwo-dimensionaltrilateration.
GPS Working
![Page 3: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/3.jpg)
2-D Trilateration
ImagineyouaresomewhereintheUnitedStatesandyouareTOTALLYlost--forwhateverreason,youhaveabsolutelynocluewhereyouare.Youfindafriendlylocalandask,"WhereamI?"Hesays,"Youare625milesfromBoise,Idaho."Thisisanice,hardfact,butitisnotparticularlyusefulbyitself.YoucouldbeanywhereonacirclearoundBoisethathasaradiusof625miles,likethis:Youasksomebodyelsewhereyouare,andshesays,"Youare690milesfromMinneapolis,Minnesota."Nowyou'regettingsomewhere.IfyoucombinethisinformationwiththeBoiseinformation,youhavetwocirclesthatintersect.Younowknowthatyoumustbeatoneofthesetwointersectionpoints,ifyouare625milesfromBoiseand690milesfromMinneapolis.
Ifathirdpersontellsyouthatyouare615milesfromTucson,Arizona,youcaneliminateoneofthepossibilities,becausethethirdcirclewillonlyintersectwithoneofthesepoints.Younowknowexactlywhereyouare--Denver,Colorado.
![Page 4: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/4.jpg)
3-D Trilateration
Fundamentally,three-dimensionaltrilaterationisn'tmuchdifferentfromtwo-dimensionaltrilateration,butit'salittletrickiertovisualize.Imaginetheradiifromthepreviousexamplesgoingoffinalldirections.Soinsteadofaseriesofcircles,yougetaseriesofspheres.
Inordertomakethissimplecalculation,then,theGPSreceiverhastoknowtwothings:
•Thelocationofatleastthreesatellitesaboveyou•Thedistancebetweenyouandeachofthosesatellites
![Page 5: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/5.jpg)
GPSSolutions
![Page 6: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/6.jpg)
TC6000GN
• GPS module NMEA output• GPSall-in-onemodule• GPStrackingsensitivity-162dBm• Verysmallpackage• Onesinglepowersupply• Lowpowerconsumption• IntegratedLNAandTCXO
![Page 7: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/7.jpg)
TC6000GN
• TC6000GN-P1isahighperformancefullyautonomousGPSmodulethatoutputsNMEAonaserialportandminimizestheloadonthehostprocessor. Protocol communicationisNMEA(providestime,position,speed,satellitestatus,andcourse)
• Addinganantenna,a32,768Hzclockandasingle1.8Vpowersupplywillformacompleteantenna–to-NMEAhighperformanceGPSsolution.
• TC6000GN-P1isafullyautonomousGPSmodulethatoutputsNMEAonaserialportwithminimalrequirementfromahostprocessor.
• Dependingontheapplication,differentconfigurationsandadditionalcomponentsmustbeadded.
![Page 8: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/8.jpg)
![Page 9: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/9.jpg)
Referencecircuit
• ThecircuitshowsanimplementationwithalevelshifterthatallowstoconnectTC6000GN-P1to3.3Vsystem.The3.3Vto1.8Vregulator(LDOorswitchmode)isnotshown.
• ALEDdriverisshowntoindicatethecurrentfixmodebyaLED• ThePUSH_TO_FIXpinisavailableontheinputofthelevelshiftertoallow
anexternalcontrollertoputtheTC6000GN-P1todeepsleep.• Fortheantenna,twodifferentoptionsareshown.Apassiveantennawith
matchingandaconnectorforanactiveantennaalternatively.Theactiveantennaconfigurationincludesthedecoupledantennasupplyvoltage.ThecoilblockstheRFpathtothesupply,thecapacitorblockstheDCpathtowardstheGPS_RFinput
• TheGPSresetisshownwiththreeoptions:resetthroughR/Ccircuit,throughmicrocontrollerorthroughaspecialresetchip,thatgeneratestheresetpulse.
• The32,768Hzclockcanbeprovidedbyadedicatedoscillatorcircuitorbyfeedinganexternalclock
![Page 10: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/10.jpg)
![Page 11: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/11.jpg)
--UARTmoduleintheMSP430toenablecommunicationswithacomputer.
--TheUniversalAsynchronousReceiver/Transmitter(UART)moduleispartofboththeUniversalSerialCommunicationInterface(USCI)Moduleandtheuniversalsynchronous/asynchronousreceive/transmit(USART)Module.
--DependingonwhichderivativeoftheMSP430youareusing,youwilluseeitherUSCIorUSARTandenableoneofthemodesofoperationsuchasUART,SPI,I2C,etc.
UART
![Page 12: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/12.jpg)
Hardware Connection
--UARTissimpletoconnectandituses2lines:TX(Transmit)andRX(Receive).Noclockisrequiredbecauseit’sasynchronous.
--WheninterfacedtoanothermodulethatusesUART,youwillneedtocrossconnectthelines.TheTXofonedevicewillconnecttotheRXofanotherdevice,whiletheRXwillbeconnectedtotheTXoftheseconddevice.
--RS232isacommonconnectionbetweenPCanddevices,anditcanbeeasilyconvertedtoRS232usingalevelconverter.
--AnotherpopularsolutionistoconnecttheUARToftheMSP430toaUSBtoUARTconvertersuchastheFT232RLandFT2232fromFTDICHIP.TheseIcscreatesavirtualCOMportonthehostmachinethatallowsyoutoseamlesslytransferbytesbetweenthehostmachineandtheMSP430.
![Page 13: - When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth- orbiting.](https://reader035.fdocuments.in/reader035/viewer/2022072010/56649dd05503460f94ac517d/html5/thumbnails/13.jpg)
UART connectivity on the MSP430F5435