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Trimble Outdoors 44326-00-ENG GPS Receiver User Manual

1. e e 69 navGetOscStatus gi arte eos a ee A 70 Navinit Time ws aaa e A eae SO ek 71 navPutDgpsCorrParams o 72 navPutNavConfig 0000000 00 73 navPutOscFreqO f SEt o oo e 74 navGetSvSelections o 75 navGetTempParams 76 navStartTempMeasS e e 78 navGpsShutDoWO o e 79 EE Goede ala Soleo ee Gg a E 80 navPutInitPosition 2 000000 81 Glossary Index FirstGPS Starter Kit User Guide About This Manual Welcome to the FirstGPS Starter Kit User Guide This manual describes how to install set up and use the FirstGPS Application Programming Interface APD If you are not familiar with the Global Positioning System GPS visit our Web site for an interactive look at Trimble and GPS at www trimble com Trimble assumes that you are familiar with Microsoft Windows and know how to use a mouse select options from menus and dialogs make selections from lists and refer to online help FirstGPS Starter Kit User Guide ix About This Manual x Related Information This manual is provided in portable document format PDF Other sources of related information are Help The software has built in context sensitive help that lets you quickly find the information you need Access it from the Help menu Alternatively click the Help button in a dialo
2. Format npRetCode navGetOscStatus npOscStatusType ptOscStatus Output Parameter Data Type Parameter Description npOscStatus Type ptOscStatus Contains oscillator and frequency offset information For a complete listing refer to nopOscStatus Type page 48 Return Values Value Description NAV_OK The oscillator drift offset has been retrieved successfully NAV_ERROR The oscillator drift offset has not been retrieved successfully 70 FirstGPS Starter Kit User Guide Using the FirstGPS API A navinitTime Put current time Description Imports an external GPS time into the navigation platform It adjusts the local GPS time immediately and the GPS time on the measurement platform through message passing The GPS time is only permitted to override the current clock value if the current time has not been set that is no satellites are tracked The primary purpose of this function is to reduce the time to the first fix Included Header File include npStdIface h Format npRetCode navInitTime U16 usGpsWn U32 ulGpsTowMsec FLT fltTimeAccuracy Input Parameters Data Type Parameter Description U16 usGpsWn GPS week number into the navigation platform U32 ulGps TowMsec GPS time of week in millisecond into the navigation platform FLT fltTimeAccuracy Accuracy of input time in milliseconds 1 if unknown Return Values Value Description NAV_OK The GPS time is impor
3. Data Type Parameter Description npNavFixType ptNavFix A pointer to the npNavFixType data structure which has various representations of navigation information updated by the navigation platform For detailed descriptions of each sub field refer to npNavFixType page 45 Return Values Value Description NAV_OK The last position fix information is retrieved successfully NAV_ERROR The last position fix information is not retrieved successfully 66 FirstGPS Starter Kit User Guide Using the FirstGPS API A navGetNavConfig Get receiver settings Description This function gets a copy of the current GPS configuration Included Header File include npStdIface h Format npRetCode navGetNavConfig npNavConfigType ptNavConfig Output Parameter Data Type Parameter Description npNavConfigType ptNavConfig A copy of receiver configuration data to be updated by the navigation platform Return Values Value Description NAV_OK The receiver configuration parameters are available NAV_ERROR The receiver configuration parameters are not available FirstGPS Starter Kit User Guide 67 A Using the FirstGPS API navGetNavStatus Get navigation platform status Description This function obtains a copy of the navigation status structure Included Header File include npStdIface h Format npRetCode navGetNavStatus npNavStatusType ptNavStatus Output Parameter Data Type
4. Earth Centered Earth Fixed coordinates ECEF EMI A description of the purely geometrical contribution to the uncertainty in a position fix given by the expression DOP SQRT TRACE A where A GTG of G the geometry matrix corresponding to the measurement connection matrix for the instantaneous position solution dependent on satellite receiver geometry L The DOP factor depends on the parameters of the position fix solution Standard terms for GPS application are Geometric DOP Three position coordinates plus clock offset in the solution Position DOP Three coordinates Horizontal DOP Two horizontal coordinates Vertical DOP Height only Time DOP Clock offset only l Refer to Global Positioning System Theory and Applications Volume I Parkinson Spilker Axelrad and Enge 1996 p 413 Digital Signal Processor Dilution of precision The Cartesian coordinate system in which the X direction is the intersection of the prime meridian Greenwich with the equator The vectors rotate with the earth Z is the direction of the spin axis See Earth Centered Earth Fixed coordinates Electromagnetic interference 84 FirstGPS Starter Kit User Guide Global Positioning System GPS Horizontal DOP HDOP ICD GPS 200 IODE LO MPM NMEA PDOP Glossary A system involving the use of satellite technology to calculate an accurate three dimensional position A GPS system consists of
5. Event vs API Table Software Integration 3 EVENT DESCRIPTION EVENT ID API New position velocity fix available No new fix available New satellite tracking selection New satellite fix selection available New differential correction available Acknowledge to a request to start GPS FirstGPS library successfully started FirstGPS library successfully shut down FirstGPS library failed to initialize and start New temperature measurement data FirstGPS library fatal error generated NAV_FIX_NEW NAV_NO_FIX_NEW NAV_TRK_SELECTION_NEW NAV_FIX_SV_SEL_NEW NAV_REF_DCORR_NEW NAV_POWER_ON_ACK NAV_START_UP_COMPLETE NAV_READY_TO_SHUTDOWN NAV_START_UP_ FAILED NAV_TEMP_MEAS NAV_FATAL_ERROR navGetLastFix page 66 n a navGetChStatus page 60 navGetSvSelections page 75 navGetDgpsCorrParams page 62 navGpsStart page 80 navGpsStart page 80 navGpsShutDown page 79 navGpsStart page 80 navGetTempParams page 76 n a FirstGPS Starter Kit User Guide 35 3 Software Integration 36 FirstGPS Starter Kit User Guide Using the FirstGPS API In this chapter Overview Examples FirstGPS API Simple Data Types FirstGPS API Navigation Data Types FirstGPS API define Directives and Enumerated Data Types FirstGPS API Return Types FirstGPS API Function Descriptions A Using the FirstGPS API Overview This appendix describes the FirstGPS API data types return t
6. HEALTH_PRESENT 50 Help context sensitive x Horizontal DOP 19 41 Hot resets 21 IO Interfaces 7 IONO page 51 IONO_PRESENT 50 lonosphere information 24 L Latitude Longitude Altitude coordinates 18 least significant bit 39 Local Oscillator 6 ITimeOut 63 65 Index Measurement Platform Module 4 Memory 46 Monitor main menu 17 Monitor program 14 MPM interface motherboard 11 MPM pinouts 9 MPM port 26 MPM See Measurement Platform Module N N_DYN 53 NAV_ERROR 58 63 NAV_FIX_NEW 58 66 NAV_FIX_SV_SEL_NEW 58 NAV_INCOMPLETE 58 NAV_NO_FIX_NEW 58 NAV_OK 58 63 NAV_POWER_ON_ACK 32 58 NAV_READY_TO_SHUTDOWN 33 58 NAV_REF_DCORR_NEW 58 NAV_START_UP_COMPLETE 32 58 NAV_START_UP_FAILED 58 NAV_TEMP_MEAS 58 76 NAV_TRK_SELECTION_NEW 58 navFixType 54 55 navGetBbAddr 59 navGetChStatus 35 60 navGetCompactTime 61 navGetDgpsCorrParams 62 navGetEvent 63 navGetFixDgpsCorrection 35 navGetLastFix 34 35 66 navGetNavConfig 67 navGetNavStatus 68 navGetNavVersion 69 navGetOscStatus 70 74 navGetSvSelections 19 35 75 FirstGPS Starter Kit User Guide 89 Index navGetTempParams 35 76 navGpsShutDown 32 33 35 79 navGpsStart 32 35 59 80 Navigation data types 39 Navigation status code 52 navInitTime 71 NavObject 7 navPutDgpsCorrParams 72 navPutInitPosition 81 navPutNavConfig 73 navPutOscFreqOffset 74 navStartTempMeas 78 NMEA 22 29 NO_ALMANAC_DATA 50 npAllChStatusType 39 60 npChStatusType 39 60 npComp
7. a a ar ees aina ar aTe A 48 npTempMeasType o e i oe e e 48 npVersionTagType oaoa a 49 npVersion Type o e coc So erore ei e e a e eee eee a 49 FirstGPS API define Directives and Enumerated Data Types 50 Event Handling Constants oaa 50 Almanac Status Code oaaae oo 50 Channel Status Code aoaaa 52 Navigation Status Code aoaaa 52 DGPS Operating Mode oaaae a 52 DGPS Configuration Mode aoaaa aaa 53 Dynamic Mode Flag oaaae 53 Operating Dimension o 53 Oscillator Status Code o o ooo o 54 Position Fix Source o e ee ee 54 Position Fix Status o e e 55 Position Fix DGPS Status o o 55 Position Status Code 2 o 56 Satellite Status Code ooo o o 57 Time Status Code o a 57 Standard FirstGPS Events o o 58 FirstGPS API Return Types o o o a 58 FirstGPS API Function Descriptions 59 navGetBbAddr o o 59 navGetChStatus o e o 60 FirstGPS Starter Kit User Guide vii viii navGetCompactTiMe o 61 navGetDgpsCorrParams o 62 navGetEvent cis a a a ee 63 navGetLastE o a eg Aw nee a a haa 66 navGetNavConfig 67 navGetNavStatusS o o e a 68 nayGetNavy Version
8. e Time the day of the week and time in hours minutes seconds e Date month day and year Week and TOW the current GPS week number and time of week respectively For more information refer to navGetCompactTime page 61 FirstGPS Starter Kit User Guide 17 2 Using the Starter Kit ENU Velocity filt ENU Velocity is the current velocity updated every second in the East North Up directions in meters per second For more information refer to navGetLastFix page 66 LLA Position filt LLA Position is the current position updated every second in Latitude Longitude Altitude coordinates Units are degrees and minutes relative to the WGS 84 datum For latitude N and S denote North and South for longitude E and W denote East and West Altitude is computed in meters referenced either to mean sea level or to the WGS 84 ellipsoid depending on the output options For more information refer to navGetLastFix page 66 Receiver Status Receiver Status displays current receiver information e Mode the operating mode 2D or 3D Automatic or Manual e Health the health of the FirstGPS library e Almanac the status of the collected GPS almanac pages The window also shows how much of the almanac has been collected and displays the message complete amp current when the almanac collection has been completed For more information refer to navGetNavStatus page 68 and navGetSvSelections page 75 18 FirstGPS Sta
9. s application Proper board layout is crucial to good RF performance 4 FirstGPS Starter Kit User Guide FirstGPS Starter Kit Overview BBI BBQ LI BLOCK Vcc Matching Colossus 12 504 MHZ Network RF ASIC XTAL OSC VOLTAGE REGULATOR DSP ASIC and COOLRISC Figure 1 1 Colossus IO Block Diagram Power The hardware core requires three voltages 1 Hardware Core Voltage VCC 3 3 0 3 VDC V_RF 3 0 0 3 VDC V_CORE 2 0 0 2 VDC In a typical implementation 3 3 VDC is supplied to VCC and a voltage regulator distributes the voltage to the various components as required FirstGPS Starter Kit User Guide 5 1 6 FirstGPS Starter Kit Overview Oscillator The Local Oscillator LO for FirstGPS can be either 12 504 MHz or 13 000 MHz The crystal must be accurate to within 10 PPM Trimble recommends a Temperature Compensated Crystal Oscillator TCXO Colossus RFIC The GPS signal conversion from an analog signal to digital data is performed by the Colossus RF ASIC This ASIC contains a two stage down converter using a 1400 MHz VCO located inside the chip The first conversion brings the GPS signal from 1575 42 MHz L1 to an Intermediate Frequency IF of 175 42 MHz The second conversion is to the pseudo base band frequency of 84 kHz After the second conversion the GPS signal is divided into I and Q bits which are in phase quadrature with respect to each other The J and Q bits are passed thro
10. the Product shall be free from defects in materials and workmanship and will substantially conform to Trimble s applicable published specifications for the Product for a period of one 1 year starting from the date of delivery The warranty set forth in this paragraph shall not apply to software firmware products Software and Firmware License Limited Warranty This Trimble software and or firmware product the Software is licensed and not sold Its use is governed by the provisions of the applicable End User License Agreement EULA if any included with the Software In the absence of a separate EULA included with the Software providing different limited warranty terms exclusions and limitations the following terms and conditions shall apply Trimble warrants that this Trimble Software product will substantially conform to Trimble s applicable published specifications for the Software for a period of ninety 90 days starting from the date of delivery Warranty Remedies Trimble s sole liability and your exclusive remedy under the warranties set forth above shall be at Trimble s option to repair or replace any Product or Software that fails to conform to such warranty Nonconforming Product or refund the purchase price paid by you for any such Nonconforming Product upon your return of any Nonconforming Product to Trimble in accordance with Trimble s standard return material authorization proce
11. which is the number of 1024 week periods since 6 January 1980 Tools Menu The following sections describe the three Tools menu items TTFF Test Setup Select Tools TTFF Test Setup to configure and run a time to first fix TTFF test FirstGPS Starter Kit User Guide 27 2 28 Using the Starter Kit TTFF Statistics Select Tools TIFF Statistics to display TTFF statistics Position Accuracy Select Tools Position Accuracy to display the position accuracy relative to the specified reference position By default the reference position is the first position fix generated by the FirstGPS library This feature is useful only when the MPM is stationary and its exact position is known Window Menu The Window menu offers one item Always On Top Select Window Always on Top to have the GUI window always visible on the screen never overlapped by other windows Help Menu The Help menu offers two items Product Info Select Help Product Info to display product information For more information refer to navGetNavVersion page 69 About Select Help About to display the About dialog with copyright and contact information FirstGPS Starter Kit User Guide Using the Starter Kit 2 Configuring FirstGPS Monitor for the Output Protocols The FirstGPS Monitor supports NMEA the industry standard ASCII output protocol which can be used through a serial interface from a PC COM port To configure the FirstGP
12. 19 Satellite Data coc a aa ee AL de 19 Program Status 2 2 0 002000000022 20 FirstGPS Monitor Features 2 2 20 File Menus cs i hse A a ae A ha Baek 20 Initialize Meni oia eas ea A ea a ee Eo 20 NEW Ment ne ok A Mh e A E Ca eo ed da 22 Configure Mel 25 Tools Ment naie ra e Blew oes a nan a dee Ga oo Ds 27 Window Menu iuris a a Gre Sas A 28 Help Ment censos e A A 28 Configuring FirstGPS Monitor for the Output Protocols 29 Software Integration OVETVIEW a a A Aia aes BAAS 32 Power Up and Power Down o 32 Polled vs Event Driven Data Collection 33 Event vs API Tables 2 0 0 sia a a a ae 35 Using the FirstGPS API OVEIVIEW oi a e AE 38 Examples s manera A Gade SOS ay ee Od 38 FirstGPS API Simple Data Types 00 38 FirstGPS API Navigation Data Types o 39 npAllChStatusType o o 39 npChStatusType e 39 npCompTimeType 20004 40 npDepsCorrType o o 40 NPDOP LYPe eo OSes ir e tea a e a 41 FirstGPS Starter Kit User Guide npErrorEStIYDE ui o aa ies a bs se ee Gk 41 npPixChTypes 2000000 sonia aor wed eects a aa Reca 41 npFixSvSelType 020 000 000005 42 NPR TY Pees a BI BS A Te 43 npNavConfigType e sa sa e see sia e n 00000 44 npNavFixType s edice s e a e i o e 45 npNavStatus Type si saner at a pE hE oa a O A R 46 npOscStatusType 2
13. Based on position timing fix HAOSC_APPX 3 Approximate 1 SV solution HAOSC_MEAS 4 Have knowledge from raw measurement Position Fix Source Source of the current position fix contained in the ucSource field of the navFixType structure Define Value Description FIX_SOURCE_NONE 0 No position in memory FIX_SOURCE_INIT 1 Position came from outside receiver and is approximate FIX_SOURCE_ACCU 2 Position came from outside receiver and is accurate to within 100 meters FIX_SOURCE_2D 3 2D fix FIX_SOURCE_3D 3D fix FIX_SOURCE_OLD 5 Fix is considered old but is trusted from 5 4 FirstGPS Starter Kit User Guide selected satellites Using the FirstGPS API A Position Fix Status Status of the current position fix contained in the ucStatus field of the navFixType structure Define Value Description FIX_STATUS_NONE 0 No position in memory FIX_STATUS_OLD 1 Fix is considered old but is trusted from selected satellites FIX_STATUS_NEW 2 Fix is valid and new Position Fix DGPS Status Indicates if the position fix is differentially corrected Define Value Description FIX_GPS_NOT_CORRECTED 0 Fix is not differentially corrected FIX_DGPS_CORRECTED 1 Fix is differentially corrected FirstGPS Starter Kit User Guide 55 Using the FirstGPS API Position Status Code Status flag ucPosStatus has the following valid values Only the values 4 7 and 0x80 4 7 should be considered to indicate that a valid position
14. North Up or ECEF coordinates Timing Output Select View Timing Output to change the output time format either GPS or UTC reference The difference between UTC and GPS is equal to the number of leap seconds added since 1970 Signal Level Output Select View Signal Level Output to change the satellite signal level output format to either AMU or CNO For definitions of these terms see page 83 The signal level is displayed in the Satellite Data section of the main application window Almanac Pages Select View Almanac Pages to display GPS data for each of the collected satellite almanac pages Refer to the JCD GPS 200 specification for definitions of the almanac terms Almanac Health Select View Almanac Health to display GPS data for the almanac health page For more information refer to the npNavStatus Type ulAlmHealthStatus parameter on page 47 FirstGPS Starter Kit User Guide 23 2 24 Using the Starter Kit Ephemeris Pages Select View Ephemeris Pages to display GPS data for each of the collected satellite ephemeris pages Refer to the ICD GPS 200 specification for definitions of the ephemeris terms lonosphere Info Select View Ionosphere Info to display GPS data for the ionospheric model data page Refer to the JCD GPS 200 specification for definitions of the ionosphere information terms UTC Page Info Select View UTC Page Info to display GPS data for the UTC data page Refer to the ICD GP
15. Parameter Description npNavStatus Type ptNavStatus A structure containing Navigation status parameters Return Values Value Description NAV_OK The Navigation status is obtained successfully from the navigation platform NAV_ERROR The Navigation status is not obtained successfully from the navigation platform 68 FirstGPS Starter Kit User Guide Using the FirstGPS API A navGetNavVersion Get navigation platform version Description This function gets a copy of the software version for the measurement platform firmware navigation platform API navigation platform software native RTOS and native processor Included Header File include npStdIface h Format npRetCode navGetNav Version np VersionType ptVersion Output Parameter Data Type Parameter Description npVersionType ptVersion A pointer to a version structure to be updated by the navigation platform For detailed descriptions of each sub field refer to npVersionType page 49 Return Values Value Description NAV_OK The firmware version is retrieved successfully NAV_ERROR The firmware version is not retrieved successfully FirstGPS Starter Kit User Guide 69 A Using the FirstGPS API navGetOscStatus Get oscillator offset status Description navGetOscStatus gets the navigation platform s current estimates of oscillator bias frequency offset and their uncertainties Included Header File include npStdIface h
16. a space segment up to 24 NAVSTAR satellites in six different orbits the control segment five monitor stations one master control station and three upload stations and the user segment GPS receivers NAVSTAR satellites carry extremely accurate atomic clocks and broadcast coherent simultaneous signals See Dilution of precision GPS Interface Control Document ICD GPS 200 IRN 200B PR 00J Rev B PR U S Air Force July 1 1992 Search for this document on the Web site http www space com af mil usspace gps_support gps_documentation htm Intermediate frequency Issue of data ephemeris Local oscillator Measurement Platform Module A standard established by the National Marine Electronics Association NMEA that defines electrical signals data transmission protocol timing and sentence formats for communicating navigation data between marine navigation instruments A measure of the quality of the GPS position PDOP values below 7 are satisfactory the ideal PDOP value is one and values from 2 to 4 are good See Dilution of precision FirstGPS Starter Kit User Guide 85 Glossary PRN PVT Real time RFIC RTOS SAW sv TDOP TTFF TCO TCXO UTC VDOP XTAL Pseudo random noise Position Velocity Time This term means to be performed immediately not at some later time Radio Frequency Integrated Circuit Real time Operating System Surface acoustic wave Space vehicle that is GPS sat
17. is available for output navigation Define Value Description HAVE_POS_NONE 0 No position in memory HAVE_POS_INIT 1 Position came from outside receiver and is approximate HAVE_POS_ACCU 3 Position came from outside receiver and is accurate to within 100 meters HAVE_POS_FIX2A 4 2D fix in auto 2D 3D mode HAVE_POS_FIX2M 5 2D fix in manual 2D mode HAVE_POS_FIX3A 6 3D fix in auto 2D 3D mode HAVE_POS_FIX3M 7 3D fix in manual 2D 3D mode HAVE_POS_DFIX2A HAVE_POS_DFIX2M HAVE_POS_DFIX3A HAVE_POS_DFIX3M HAVE_POS_OLD HAVE_POS_APPX HAVE_POS_AVSV HAVE_POS_FRIM HAVE_POS_INTERNAL HAVE_POS_FIX2A 0x80 HAVE_POS_FIX2M 0x80 HAVE_POS_FIX3A 0x80 HAVE_POS_FIX3M 0x80 10 11 12 Same as HAVE_POS_FIX2A but differential mode Same as HAVE_POS_FIX2M but differential mode Same as HAVE_POS_FIX3A but differential mode Same as HAVE_POS_FIX3M but differential mode Fix is considered old but is trusted from selected satellites Fix is converging Fix is converging Fix is converging Internal fix not suitable for use 56 FirstGPS Starter Kit User Guide Satellite Status Code Using the FirstGPS API A Define Value Description SCODE_DOING_FIXES 0 Doing position fixes SCODE_ GOOD _1SV 1 A usable SV is available SCODE_NEED_TIME 2 Need GPS time SCODE_PDOP_HIGH 3 PDOP is too high SCODE_BAD_1SV 4 The chosen SV is unusable SCODE_0SVS 5 No usable satellites SCODE_1SV 6 Onl
18. navigation platform For complete details refer to npDgpsCorrType page 40 U8 pucCount Indicates number of valid entries Return Values Value Description NAV_OK The differential correction parameters are available NAV_ERROR The differential correction parameters are not available 62 FirstGPS Starter Kit User Guide Using the FirstGPS API A navGetEvent Retrieve a FirstGPS event Description The events are queued up internally inside the FirstGPS library To retrieve the events in the FIFO order First In First Out pass EVENT_GET_FIRST for ucGetFlag Otherwise use EVENT_GET_LAST This retrieves the most recent event If no events have been generated at the time when this function is called the calling task will be suspended until an event has been generated Pass the ID of the calling task in pvTaskId This must be an RTOS specific pointer to a type of the task control block used by the RTOS This pointer will be cast to a task type relevant to the RTOS which will allow the FirstGPS library to suspend the calling task TimeOut specifies the timeout value in milliseconds after which the suspended task will be resumed If the task times out and no event has been generated yet NAV_ERROR is returned If some event has been generated before this function was called the event will be retrieved as specified by the ucGetFlag value and the function will return immediately Otherwise the function will suspend the ca
19. software version npVersionTagType tRtosVer Native RTOS version npVersionTagType tCpuVer Native processor version FirstGPS Starter Kit User Guide 49 A Using the FirstGPS API FirstGPS API define Directives and Enumerated Data Types Event Handling Constants Define Value Description EVENT_NO_WAIT 0 For more information refer to the TimeOut parameter of navGetEvent page 63 EVENT_WAIT_FOREVER 1 For more information refer to the TimeOut parameter of navGetEvent page 63 EVENT_GET_FIRST 0 For more information refer to the ucGetFlag parameter of navGetEvent page 63 EVENT_GET_LAST 1 For more information refer to the ucGetFlag parameter of navGetEvent page 63 Almanac Status Code Define Value Description NO_ALMANAC_ DATA 0 There is no almanac data in the database HEALTH_PRESENT 1 ALM_PAGES_ PRESENT 2 Almanac is complete and current UTC_PRESENT 4 Indicates UTC page is collected IONO_PRESENT 8 Indicates almanac health page is collected Indicates ionospheric page is collected For the almanac status flag if the value is 0 then there is no almanac data in the receiver This is the normal situation after a cold reset It is possible that a complete almanac was not collected before the receiver was turned off after a cold reset When the value is non zero some almanac pages are present in the receiver A value of 15 indicates the desired condition namely that the almanac is c
20. system data such as the almanac ephemeris UTC JONO sphere information Loading the current BBRAM file allows for faster TTFF 26 FirstGPS Starter Kit User Guide Using the Starter Kit 2 This file does not come with the distribution of the FirstGPS Monitor application Rather it is generated automatically when the application runs for the first time and the Save BBRAM on exit option is selected Usually it takes about 15 minutes of tracking GPS signals before the BBRAM file is completely filled with GPS almanac pages On consecutive starts if the FirstGPS Monitor has been properly stopped using the Initialize Stop menu item the BBRAM file is saved in the same directory as the GUI executable Having this file available at the next power up makes the TTFF much faster e Save BBRAM on exit This option enables the generation of the BBRAM file as described in the previous paragraph e Smooth Dialog Resize This option enables a smooth slide out effect when various GUI dialog boxes are displayed e Clock This option enables selection of the LO to 12 504 MHz or 13 000 MHz The MPM in the Starter Kit comes with a 12 504 MHz crystal The FirstGPS library will not run unless the Clock option is properly set Num Channels This option enables selection of the number of channels of the MPM unit The MPM comes with 12 channels e Week Epoch This option enables selection of the week epoch number
21. 8 ucNumSvsUsed Number of SVs used U8 ucStatus Indicates the validity status of this fix For more information refer to Position Fix Status page 55 U8 ucSource Indicates the source of this position fix For more information refer to Position Fix Source page 54 U8 ucDgpsFlag Differential GPS status For more information refer to Position Fix DGPS Status page 55 FirstGPS Starter Kit User Guide 45 A 46 Using the FirstGPS API npNavStatusType npNavStatusType contains a set of status words for the following important data items GPS position availability Specifies the state of the GPS position solution that is whether any position is available for use by the receiver or its source and whether it came from outside the receiver or was computed internally GPS time availability Specifies the state of the GPS time solution that is whether the time came from outside the receiver from one satellite or from a GPS fix Receiver oscillator frequency offset availability Specifies whether the receiver has an estimate of its oscillator frequency offset and where it came from Memory Specifies if any non volatile memory was available when the receiver began the current start up cycle Ephemeris Each bit in this variable represents the ephemeris status of a particular satellite 1 32 The bit is one 1 if the ephemeris is in memory and valid Otherwise the bit is zero 0 This field can be used to d
22. 9 40 ucSvUsed 41 ucTimeStatus 47 80 ulAlmHealthStatus 47 ulAlmPageStatus 47 ulEphStatus 47 ulGpgMsec 80 ulGpsTowMsec 39 71 92 FirstGPS Starter Kit User Guide ulMeasCount 48 ulMeasMsec 48 76 ulMsecs 40 ulTimeOfReception 40 usGpsWeek 80 usGpsWn 71 usMeasStatus 39 usRefScount 40 usReserved 39 usWeeks 40 usWeekTag 45 usYear 49 UTC page 24 51 UTC_PRESENT 50 V VDOP See Vertical DOP Velocity 18 Vertical DOP 19 41 Visual position 22 Voltages 5 W Warm resets 21 Week epoch 27 World Wide Web site 1x Reader Comment Form FirstGPS Starter Kit User Guide March 2001 P N 44326 00 ENG Revision A We appreciate your comments and suggestions for improving this publication Contributors of particularly helpful evaluations will receive a thank you gift I use the following Trimble product for Please circle a response for each of the statements below 1 Strongly Agree 2 Agree 3 Neutral 4 Disagree 5 Strongly Disagree 3 5 The manual is well organized 1 I can find the information I want The information in the manual is accurate I can easily understand the instructions The manual contains enough examples The examples are appropriate and helpful NNN NN NW WwW U U Ww W qu bh The layout and format are attractive and useful Rh a gt NNA Ur Ur Ur Un Un 2 3 4 The manual is too long just right too short Please answer the following questions The illustrations are clear and
23. B to 14 dB of gain at the antenna connector on board for best performance Power Supply There are two ways to power the MPM Starter Kit using either the DC power cable or the AC DC converter For DC 1 Connect the terminated end of the power cable to the power connector on the interface unit 2 Connect the red lead to positive voltage 9 to 32 VDC 3 Connect the black lead to GND The yellow lead is not used For AC 1 Connect the output cable of the converter to the 3 pin power connector on the interface unit 2 Using an appropriate three prong AC power cable not provided connect the converter to an AC wall socket 110 VAC or 220 VAC Software See Chapter 2 Using the Starter Kit 12 FirstGPS Starter Kit User Guide Using the Starter Kit This chapter includes the following topics Touring the Sample Application Running the FirstGPS Starter Kit for the First Time Running the FirstGPS Starter Kit FirstGPS Monitor Main User Interface FirstGPS Monitor Features Configuring FirstGPS Monitor for the Output Protocols 2 Using the Starter Kit Touring the Sample Application This section provides a brief overview of the FirstGPS Starter Kit and Monitor program The Monitor program is a graphical user interface GUI application which exercises the Trimble FirstGPS software library to generate position time and velocity information in a user friendly visual Windows environment The program allows per
24. DEALING WHICH DEVELOPS OR HAS DEVELOPED BETWEEN YOU AND TRIMBLE BECAUSE SOME STATES AND JURISDICTIONS DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES THE ABOVE LIMITATION MAY NOT APPLY TO YOU Contents About This Manual Related Information x Technical Assistance 2 e xi Your COMME Sic dt aa Bike ae we a RS xi Document Conventions ooe e e e e e 0000802 a xii FirstGPS Starter Kit Overview Purpose of the Starter Kit 2 2 o 2 FirstGPS Architecture oaa a 2 Input Output Interface oaa a 4 FirstGPS Softwaree vos uane e a E be 8 Application bayer orep ira a A a ee I a 9 Starter Kit Components o 9 Measurement Platform Module MPM 9 Motherboard surs ioa aca ed o ta SG 11 Antennas 3 aa ft eh Rati ie o har ee one E 12 Power Supply o saci e ep bee RS Bo oA ee 12 NN St Sas cetacean ee BM ee eee 12 Using the Starter Kit Touring the Sample Application o 14 Running the FirstGPS Starter Kit for the First Time 14 Running the FirstGPS Starter Kit o o 16 FirstGPS Monitor Main User Interface 17 Time GPS sc a ic a A a EA 17 ENU Velocity Hilt 0 0s seh a a AP a 18 FirstGPS Starter Kit User Guide v vi LLA Position filt 18 Rec lver Status its aa ds a ada awe o 18 DORS e e e la 19 Firmware Info ot a rt a a Be A ia
25. FirstGPS Starter Kit User Guide Version 1 0 Part Number 44326 00 ENG Revision A Trimble March 2001 Corporate Office Trimble Navigation Limited 645 North Mary Avenue Post Office Box 3642 Sunnyvale CA 94088 3642 U S A Phone 1 408 481 8940 1 800 545 7762 www trimble com Support Offices For support in Europe call 44 1256 746 239 or send a fax to 44 1256 760 148 For support outside Europe call 1 408 48 1 8786 or send a fax to 1 408 481 2011 Copyright 2001 Trimble Navigation Limited All rights reserved Trademarks The Sextant logo with Trimble is a trademark of Trimble Navigation Limited registered in the United States Patent and Trademark Office The Globe amp Triangle Trimble FirstGPS and Colossus are trademarks of Trimble Navigation Limited All other trademarks are the property of their respective owners Release Notice This is the March 2001 release of the FirstGPS Starter Kit User Guide part number 44326 00 ENG It applies to version 1 0 of the FirstGPS API software The following limited warranties give you specific legal rights You may have others which vary from state jurisdiction to state jurisdiction The following limited warranties give you specific legal rights You may have others which vary from state jurisdiction to state jurisdiction Hardware Limited Warranty Trimble warrants that this Trimble hardware product
26. GPS data Performing a hot reset assumes that you have operated the MPM long enough to collect almanac and ephemeris information and calculate PVT A typical hot reset results in a TTFF of about 15 seconds Set 2D Ref Altitude Select Initialize 2D Ref Altitude to prompt for a reference altitude for the receiver while operating in the 2D mode PPS Output Select Initialize PPS Output to enable the PPS output on the MPM board FirstGPS Starter Kit User Guide 21 2 Using the Starter Kit View Menu The following sections describe the sixteen View menu items Plots Select View Plots to display a Real time Position Plot and a Real time Sky Plot Real time Position Plot Erase Grid Zoom In Zoom Out SELECTION SET SEARCHING TRACKING 37 23568 N 122 2 261 W 13 57 Speed 0 0 mi hr yl Protocol Output Select View Protocol Output to view output data in the industry standard NMEA protocol in a separate window Click Configure in the output window to set up the protocol output options When you select to view NMEA output the window displays ASCII NMEA sentences 22 FirstGPS Starter Kit User Guide Using the Starter Kit 2 Position Output Select View Position Output to change the output position format either latitude longitude altitude or Cartesian Earth Centered Earth Fixed ECEF coordinates Velocity Output Select View Velocity Output to change the output velocity format either East
27. H_DGPS_CORR 52 EPH_GOOD 52 EPH_USED_IN_FIX 52 Ephemeris 46 Ephemeris pages 24 EVEN_WAIT_FOREVER 50 Event handling constants 50 EVENT_GET_FIRST 50 63 EVENT_GET_LAST 50 63 EVENT_NO_WAIT 50 Event driven data collection 33 F Firmware information 19 FIX_DGPS_CORRECTED 55 FIX_GPS_NOT_CORRECTED 55 FIX_SOURCE_2D 54 FIX_SOURCE_3D 54 FIX_SOURCE_ACCU 54 FIX_SOURCE_INIT 54 FIX_SOURCE_NONE 54 FIX_SOURCE_OLD 54 FIX_STATUS_NEW 55 FIX_STATUS_NONE 55 FIX_STATUS_OLD 55 flt3D 41 88 FirstGPS Starter Kit User Guide fltAccuFlag 81 fltAmuMask 44 fltAzimuth 39 fltBiasUnc 48 fltDopMask 44 fltElev 39 fltElevMask 44 fltFreqOffsetUnc 48 fltFreqSearch 74 fltHDOP 41 fltHoriz 41 fltMaxOscOffset 44 fltOscFreq 45 fltPDOP 41 fltPdopSwitch 44 fltPre 40 fltPrcErrEst 40 fltReserved 41 fltRre 40 fitRrcDot 40 flt1TDOP 41 fltTime 41 fltTimeAccuracy 71 80 fltVDOP 41 fltVelECEF 45 fltVelEnu 43 fltVert 41 FTP site x Function descriptions 59 G GPS position availability 46 GPS system messages 24 GPS time availability 46 H HAOSC_APPX 54 HAOSC_FIX 54 HAOSC_MEAS 54 HAOSC_OLD 54 HAOSC_UNKNOWN 54 Hardware core voltages 5 HAVE_POS_ACCU 56 HAVE_POS_APPX 56 HAVE_POS_AVSV 56 HAVE_POS_DFIX2A 56 HAVE_POS_DFIX2M 56 HAVE_POS_DFIX3A 56 HAVE_POS_DFIX3M 56 HAVE_POS_FIX2A 56 HAVE_POS_FIX2M 56 HAVE_POS_FIX3A 56 HAVE_POS_FIX3M 56 HAVE_POS_FRIM 56 HAVE_POS_ INTERNAL 56 HAVE_POS_NONE 56 HAVE_POS_OLD 56 HDOP See Horizontal DOP
28. Interval The number of milliseconds over which the temperature measurement is made Return Values Value Description NAV_OK The message is sent successfully to the measurement platform NAV_ERROR The message is not sent successfully to the measurement platform 78 FirstGPS Starter Kit User Guide Using the FirstGPS API A navGpsShutDown Value NAV_OK NAV_ERROR Shutdown navigation platform Description The shutdown function causes an immediate clearing of all the resources allocated in the startup It is important to call the shutdown function before removing the power from a receiver Failure to do so causes a longer startup time on the subsequent start It will take from 1 to 2 seconds to complete the shutdown Included Header File include npStdIface h Format npRetCode navGpsShutDown void Parameters N A Return Values Description The shutdown of navigation platform is successful The shutdown of navigation platform is not successful FirstGPS Starter Kit User Guide 79 A Using the FirstGPS API navGpsStart Navigation platform startup Description This is the entry point of the navigation platform It creates all the necessary tasks and allocates all the global resources used within the navigation platform It also has a set of input parameters which allows an application task to enter the initial time and accuracy of that initial time to reduce the time needed to determin
29. L pdbIPosLLA Initial position from user This is an array of three doubles which has the following order latitude longitude and altitude FLT fltAccuFlag Indicates the accuracy in meters Value 0 means do not change and all negative values indicate not accurate Return Values Value Description NAV_OK The initialization of position is successful NAV_ERROR The initialization of position is not successful FirstGPS Starter Kit User Guide 81 A Using the FirstGPS API 82 FirstGPS Starter Kit User Guide Glossary This section defines technical terms and abbreviations used in this manual AMU ASIC ASCII API BBRAM CNO Differential Global Positioning System DGPS A Trimble term Arbitrary Measurement Unit The AMU is defined as 207210 AMU 22 8 CNO where CNO C Ng that is the carrier to noise ratio Application specific integrated circuit American Standards Committee for Information Interchange This organization established a hexadecimal to printed character translation table used by all computers to store character information Application Programming Interface Battery Backed up RAM See Start Stop GPS page 20 and Load BBRAM on start page 26 Carrier to noise ratio See AMU GPS positions can be differentially corrected DGPS in real time using radio telemetry or through postprocessing no radio telemetry required Glossary Dilution of precision DOP DSP DOP
30. NAV_TEMP_MEAS 27 NAV_FATAL_ERROR 28 software FirstGPS software started Status valid FirstGPS software ended User can shutdown the application FirstGPS software startup failed Temperature measurement updated FirstGPS software fatal error generated TNAV_FATAL_ERROR indicates that a fatal error has occurred and that the library has been shut down To restart the library call navGpsStart page 80 FirstGPS API Return Types The currently defined return types are Define Value NAV_ERROR 1 NAV_OK 0 NAV_INCOMPLETE Description A function call failed A function call is successful Data retrieved is not complete npRetCode is the FirstGPS API function return type that enumerates the above values 58 FirstGPS Starter Kit User Guide Using the FirstGPS API A FirstGPS API Function Descriptions navGetBbAddr Get starting BBRAM address Description The function navGetBbAdar provides the calling application with the size and address location of the battery backed up memory BBRAM section during the power up or power down sequence During power up it is called by the host application prior to calling the navGpsStart function Included Header File include npStdIface h Format npRetCode navGetBbAddr U8 ppucAddr U32 pulSize OutPut Parameters Data Type Parameter Description U8 ppucAddr A pointer to a pointer which contains the BBRAM beginning address upda
31. O HAS BEEN INVOLVED IN ITS CREATION PRODUCTION INSTALLATION OR DISTRIBUTION INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE TITLE AND NONINFRINGEMENT THE STATED EXPRESS WARRANTIES ARE IN LIEU OF ALL OBLIGATIONS OR LIABILITIES ON THE PART OF TRIMBLE ARISING OUT OF OR IN CONNECTION WITH ANY PRODUCTS OR SOFTWARE SOME STATES AND JURISDICTIONS DO NOT ALLOW LIMITATIONS ON DURATION OR THE EXCLUSION OF AN IMPLIED WARRANTY SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU TRIMBLE NAVIGATION LIMITED IS NOT RESPONSIBLE FOR THE OPERATION OR FAILURE OF OPERATION OF GPS SATELLITES OR THE AVAILABILITY OF GPS SATELLITE SIGNALS Limitation of Liability TRIMBLE S ENTIRE LIABILITY UNDER ANY PROVISION HEREIN SHALL BE LIMITED TO THE GREATER OF THE AMOUNT PAID BY YOU FOR THE PRODUCT OR SOFTWARE LICENSE OR U S 25 00 TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW IN NO EVENT SHALL TRIMBLE OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHATSOEVER UNDER ANY CIRCUMSTANCE OR LEGAL THEORY RELATING IN ANY WAY TO THE PRODUCTS SOFTWARE AND ACCOMPANYING DOCUMENTATION AND MATERIALS INCLUDING WITHOUT LIMITATION DAMAGES FOR LOSS OF BUSINESS PROFITS BUSINESS INTERRUPTION LOSS OF BUSINESS INFORMATION OR ANY OTHER PECUNIARY LOSS REGARDLESS WHETHER TRIMBLE HAS BEEN ADVISED OF THE POSSIBILITY OF ANY SUCH LOSS AND REGARDLESS OF THE COURSE OF
32. O also has a temperature function Inside the IO chip is a temperature sensitive counter An API call provides the counts in real time and the counts can be converted into temperature using a simple formula FirstGPS Software The FirstGPS software library is the GPS function software core It resides on the host CPU so it shares RAM and ROM with the customer s application The library must be compiled specific to each application depending on the CPU Real time Operating System RTOS and compiler The source code is very portable written in C and it has been ported to a variety of different development environments The FirstGPS software library encompasses the complete software interface with the IO chip so the IO is essentially transparent to the application software A complete list of API calls for the FirstGPS software library is listed in Appendix A Using the FirstGPS API In general the application program uses the FirstGPS API calls to Boot the IO and start the GPS function e Initialize the receiver with non volatile memory and current time if available e Change receiver control parameters satellite masks DGPS corrections Fetch current receiver status Fetch the most recent PVT solution e Fetch ancillary data for example signal strengths e Stop the GPS function FirstGPS Starter Kit User Guide FirstGPS Starter Kit Overview 1 Application Layer The term Application Layer is used to des
33. ODE_0SVS 57 SCODE_1SV 57 SCODE_2SVS 57 SCODE_3SVS 57 SCODE_BAD_1SV 57 SCODE_DCORR_GEN 57 SCODE_DOING_FIXES 57 SCODE_GOOD_1SV 57 SCODE_NEED_TIME 57 SCODE_OVERDET_CLK 57 SCODE_PDOP_HIGH 57 sDatumIndex 45 Signal level output 23 Signal strength 19 Sky plots 22 Standard FirstGPS events 58 Index Start GPS 20 Starter Kit components 2 Starter Kit running 16 STATUS_FREQ LOCK 52 STATUS_FRESH_MEAS 52 STATUS_GOOD_PARITY 52 STATUS_HEALTHY 52 STATUS_LOCK_POINT_KNOWN 52 STATUS_PHASE_ LOCK 52 STATUS_RESET 52 STATUS_TIME_KNOWN 52 STATUS_VALID_MEAS 52 Stop GPS 21 T T_STATUS_APPX 57 T_STATUS_BIAS_KNOWN 57 T_STATUS_NONE 57 T_STATUS_PROBLEM 57 T_STATUS_SET 57 tChStatus 39 tCpuVer 49 tDop 42 45 TDOP See Time DOP Temperature 25 tErrorEst 43 tFiltFix 45 tFixCh 45 Time DOP 19 41 Time function 17 Time status code 57 tMpFwVer 49 tNpApiVer 49 tNpSwVer 49 tRawFix 45 tRtosVer 49 TTFF 27 FirstGPS Starter Kit User Guide 91 Index U ucAlmStatus 47 ucAmu5 39 41 ucBeta 49 ucClearFlag 72 ucCount 72 ucDay 49 ucDgpsAgeLlimit 44 ucDgpsCfg 44 ucDgpsFlag 45 ucDgpsMode 42 ucDimMode 42 ucDynamics 44 ucGetFlag 63 65 ucHaveBias 48 54 ucHaveFreqOffset 48 54 uclod 40 uclode 41 ucLpFixRate 44 ucMajor 49 ucMemStatus 47 ucMinor 49 ucMonth 49 ucMsecInterval 48 78 ucNavStatus 39 ucNumSvsUsed 45 ucOprtngDim 44 ucOscStatus 47 ucPosStatus 47 56 ucSatCnt 42 ucSource 45 54 ucStatus 40 42 45 55 ucSvId 3
34. ORR 32 DGPS correction is available DGPS Operating Mode Define Value Description DGPS_OFF 0 Differential GPS is off DGPS_ONLY 1 Set to differential GPS only DGPS_AUTO_OFF 2 Auto mode off DGPS_AUTO_ON 3 Auto mode on 52 FirstGPS Starter Kit User Guide Using the FirstGPS API A DGPS Configuration Mode Define Value Description DGPS_CFG_OFF 0 Differential GPS is off DGPS_CFG_ONLY 1 Set to differential GPS only DGPS_CFG_AUTO 2 Auto mode Dynamic Mode Flag Define Value Description DYN_UNDEFINED 0 Undefined dynamics DYN_LAND 1 Land dynamics DYN_SEA 2 Sea dynamics DYN_AIR 3 Air dynamics DYN_STATIONARY 4 Stationary dynamics N_DYN 5 Total number of dynamic modes Operating Dimension These definitions are used when setting the receiver s operation mode or reporting fix satellite selection Define Value Description DIM_2D 0 2D mode of operation DIM_3D 1 3D mode of operation DIM_1SV 2 1SV mode of operation DIM_AUTO 3 Auto mode of operation DIM_DGPS_REF 4 DGPS mode of operation DIM_2D_CLK_HOLD 5 2D Clock Hold mode of operation DIM_OVERDET_CLK 6 Over determined clock mode FirstGPS Starter Kit User Guide 53 A Using the FirstGPS API Oscillator Status Code Status flag for the oscillator drift bias used by the ucHaveFreqOffset and ucHaveBias fields in npOscStatusType Define Value Description HAOSC_UNKNOWN 0 No information HAOSC_OLD 1 Old HAOSC_FIX 2
35. Protocol Configuration to configure NMEA protocol output options For information on how to enable NMEA output see Configuring FirstGPS Monitor for the Output Protocols page 29 FirstGPS Starter Kit User Guide 25 2 Using the Starter Kit Data Logging Select Configure Data Logging to configure a data logging option You can log position fix data to a file in two different formats Tab delimited ASCII text Industry standard NMEA ASCII text Settings Select Configure Settings to configure the FirstGPS Monitor parameters The descriptions of the parameters in the Application Settings window follow MPM Port the serial communication port number to which the MPM unit is connected through the RS 232 interface Application Port The output protocols port settings This must be a port different from the MPM port The PC must have at least one more serial port in addition to the one used for the MPM port to use the Output Protocols feature Append port to logs Select this check box to append the MPM port number to the log file names if any log options are enabled through the Configure Data Logging menu item Sync PC time to UTC Select this check box to synchronize the local PC time to UTC once the MPM unit has started running and the exact time is known Load BBRAM on start This option enables loading the BBRAM file to the FirstGPS library when connecting to the MPM unit The BBRAM file contains the GPS
36. S 200 specification for definitions of the UTC data terms GPS System Message Select View GPS System Message to display GPS system messages for each satellite Refer to the ICD GPS 200 specification for definitions of the GPS system messages Oscillator Offset Select View Oscillator Offset to display the MPM s oscillator bias and drift updated every second For more information refer to navGetOscStatus page 70 Channel Tracking Status Select View Channel Tracking Status to hide or display the Satellite Data section in the main window of the program For more information refer to navGetChStatus page 60 and navGetSvSelections page 75 FirstGPS Starter Kit User Guide Using the Starter Kit 2 Satellite Visibility Select View Satellite Visibility to display the Satellite Visibility window which shows elevation angles of all satellites Temperature Select View Temperature to start the IO s temperature sensor reports For more information refer to navStartTempMeas page 78 and navGetTempParams page 76 Configure Menu The following sections describe the five Configure menu items Receiver Configuration Select Configure Receiver Configuration to configure the FirstGPS firmware parameters For more information refer to navGetNavConfig page 67 Filter Configuration Select Configure Filter Configuration to configure the FirstGPS filter parameters Protocol Configuration Select Configure
37. S Monitor for NMEA output you must specify the application port in the program settings using Configure Settings from the main menu The application port must be a COM port different from the one connected to the MPM unit Set the application port parameters as desired The default NMEA parameters are 4800 baud none 8 1 NMEA outputs can be viewed on an ASCII terminal emulation program such as Hyperterm This program is typically used on a second computer A single computer can be used provided that there are three COM ports one for MPM one for NMEA protocol and one for the ASCII output program An RS 232 null modem should be used for PC to PC communications FirstGPS Starter Kit User Guide 29 2 Using the Starter Kit 30 FirstGPS Starter Kit User Guide Software Integration In this chapter Overview Power Up and Power Down Polled vs Event Driven Data Collection Event vs API Table 3 Software Integration Overview The FirstGPS software library runs as a library to a host application under a Real Time Operating System RTOS This chapter discusses a few of the design implementation issues Power Up and Power Down The FirstGPS software is provided as a static library It must be linked with the user defined application task AppTask to generate object code that can be loaded onto a target environment and run It is the AppTask s responsibility to start up and shut down the FirstGPS engine as required Th
38. Time since power up e Name of the COM port on the PC FirstGPS Monitor Features The menu bar in the FirstGPS Monitor main window page 17 contains seven menus as shown below The following sections describe these menus File Menu Use File Exit to close the FirstGPS Monitor window Initialize Menu The following sections describe the six Initialize menu items Start Stop GPS When the GPS engine is not running this menu item displays Start GPS To start the GPS engine select this item 20 FirstGPS Starter Kit User Guide Using the Starter Kit 2 When the GPS engine is running this menu item displays Stop GPS To stop the GPS engine select this item Stop GPS will also save important parameters to Battery Backed up RAM BBRAM Cold Reset Select Initialize Cold Reset to restart the GPS engine and perform a firmware reset after erasing all of the collected GPS data such as the almanac and ephemeris Cold resets result in a TTFF of 2 to 3 minutes Warm Reset Select Initialize Warm Reset to restart the GPS engine and perform a firmware reset after erasing the ephemeris from the collected GPS data Performing a warm reset assumes that you have operated the MPM long enough to collect almanac information and calculate PVT A typical warm reset results in a TTFF of about 50 seconds Hot Reset Select Initialize Hot Reset to restart the GPS engine and perform a firmware reset without erasing any collected
39. TimeType 40 npDgpsCorrType 40 72 npDopType 41 npErrorEstType 41 npFixChType 41 npFixSvSelType 42 75 npFixType 43 npNavConfigType 44 npNavFixType 45 npNavStatusType 46 npOscStatusType 48 54 npRetCode 58 npTempMeasType 48 npTimeStatusType 57 npVersionTagType 49 npVersionType 49 Num channels 27 O online Help x Operating dimension 53 Oscillator offset 24 Oscillator status code 54 90 FirstGPS Starter Kit User Guide Output position 23 time 23 velocity 23 P pdblPosLLA 81 PDOP See Position DOP Plots 22 Polled data collection 33 Position 18 Position accuracy 28 Position DOP 19 41 Position fix DGPS status 55 Position fix source 54 Position fix status 55 Position status code 56 power supply 12 PPS output 21 ppucAddr 59 PRN See satellite identifier Program status 20 Protocols 22 29 ptAllChStatus 60 ptCompTime 61 ptDgpsCorr 62 72 ptFixSvSel 75 ptNavConfig 67 73 ptNavFix 66 ptNavStatus 68 ptOscStatus 70 ptTempMeas 77 ptVersion 69 pucCount 62 pulEvent 63 65 pulSize 59 pvEventData 63 65 pvTaskId 63 65 PVT serial solution 2 R reader comment form 93 readme txt file x Real time Operating System 8 Receiver oscillator frequency offset availability 46 Receiver status 18 Reference altitude 21 release notes x Reset cold 21 hot 21 warm 21 Return types 58 RF ASIC 3 S Satellite data 19 Satellite identifier PRN 19 Satellite status code 57 Satellite visibility 25 sCno 39 41 SC
40. arter Kit 2 FirstGPS Monitor Main User Interface The FirstGPS Monitor main window of the program shown below is divided into eight sections Once the GPS is running and the program 1s communicating with the MPM kit these sections are updated dynamically with current GPS information El FirstGPS tm Monitor File Initialize Yiew Configure Tools Window Help m Time GPS Receiver Status Time Tue 19 02 07 Mode 3 D Auto 9 SY Date January 02 2001 Health doing position fixes Week 1095 TOW 241327 Almanac M 82 ENU Velocity fill DOPs West 0 000 MS poop 1 51 HDOP 0 88 z lx wo 2 o o 2 a BoP El al o o o o w w A o 9 o gt alal els o gt Six s N N N o o rm N South 0 000 Down 0 000 m s m s VDOP 1 23 TDOP 0 75 LLA Position filt Firmware Info co w o A ESS 2 om mn e 00 A D oO m Mm w nj N H N La m co Latitude N 37 2356755 Longitude w 122 2 26159 Altitude 6 23 m HAE ran co nm gi co cas N NAY Version 1 99 12 18 2000 10 Version 17 07 03 31 2000 wo o gt Ss Al as BERRA e N co Txo Rx o GPS is running 00 09 59 COM5 Time GPS The Time panel displays the following relative to GPS or UTC depending on the output options Refer to Timing Output page 23
41. avGetCompactTime Get current time Description The navGetCompactTime gets the current GPS week number and GPS time of week from the navigation platform The GPS time and week number are computed based on the OS ticks elapsed since the last time reported from the measurement unit Included Header File include npStdIface h Format npRetCode navGetCompactTime npCompTimeType ptCompTime Output Parameter Data Type Parameter Description npCompTimeType ptCompTime A pointer to the noCompTimeType data structure which includes various representations of GPS time Although this function does not return a value check the ucStatus field of the ptCompTime to determine whether the ptCompTime contains a valid time or not Return Values Value Description NAV_OK The GPS time is retrieved successfully NAV_ERROR The GPS time is not retrieved successfully FirstGPS Starter Kit User Guide 61 A Using the FirstGPS API navGetDgpsCorrParams Get differential correction information Description This function gets a copy of all the current differential correction parameters available from the navigation platform s database Included Header File include npStdIface h Format npRetCode navGetDgpsCorrParams npDgpsCorrType ptDgpsCorr U8 pucCount Output Parameters Data Type Parameter Description npDgpsCorrType ptDgpsCorr A pointer to an array which contains the results from the
42. cribe the host application software This is typically software running a navigation system a cellular wireless device or any of a number of devices that benefit from knowledge of position running on a Real time Operating System RTOS This software provides at least the boot code and the user interface and it exercises the FirstGPS software library through the function calls contained in the FirstGPS API Starter Kit Components Measurement Platform Module MPM The MPM board is a Trimble assembly designed for optimal performance of the IO DSP and Colossus RF ASICs running at a reference frequency of 12 504 MHz A dual output voltage regulator is used to create the VCC_RF and VCC_Core needed to run both the Colossus and IO DSP chips The board size is a standard Trimble form factor of 32 mm x 66 mm The antenna connector is a right angle board mounted MCX connector I O interfacing is through an 8 pin male header with the following pin identities Pin Function Pin Function 1 No Connect 5 RXD 2 Power 6 PPS 3 TXD 7 SP_EN Serial Port Enable 4 VCC_Ant power for5 V antenna 8 GND FirstGPS Starter Kit User Guide 9 1 FirstGPS Starter Kit Overview Figure 1 2 shows the top layout of Trimble s MPM assembly La ON ara n O 4CILy BANG Figure 1 2 Top MPM Assembly Layout Figure 1 3 shows the bottom layout of Trimble s MPM assembly Figure 1 3 Bottom MPM Assembly Layout 10 FirstGPS Starter Kit User G
43. dures Warranty Exclusions and Disclaimer These warranties shall be applied only in the event and to the extent that i the Products and Software are properly and correctly installed configured interfaced maintained stored and operated in accordance with Trimble s relevant operator s manual and specifications and ii the Products and Software are not modified or misused The preceding warranties shall not apply to and Trimble shall not be responsible for defects or performance problems resulting from i the combination or utilization of the Product or Software with products information data systems or devices not made supplied or specified by Trimble 11 the operation of the Product or Software under any specification other than or in addition to Trimble s standard specifications for its products iii the unauthorized modification or use of the Product or Software iv damage caused by accident lightning or other electrical discharge fresh or salt water immersion or spray or v normal wear and tear on consumable parts e g batteries THE WARRANTIES ABOVE STATE TRIMBLE S ENTIRE LIABILITY AND YOUR EXCLUSIVE REMEDIES RELATING TO PERFORMANCE OF THE PRODUCTS AND SOFTWARE EXCEPT AS OTHERWISE EXPRESSLY PROVIDED HEREIN THE PRODUCTS SOFTWARE AND ACCOMPANYING DOCUMENTATION AND MATERIALS ARE PROVIDED AS IS AND WITHOUT EXPRESS OR IMPLIED WARRANTY OF ANY KIND BY EITHER TRIMBLE NAVIGATION LIMITED OR ANYONE WH
44. e this is represented by a plus sign for example Ctrl C FirstGPS Starter Kit User Guide FirstGPS Starter Kit Overview In this chapter m Purpose of the Starter Kit m FirstGPS Architecture m Starter Kit Components 1 FirstGPS Starter Kit Overview Purpose of the Starter Kit FirstGPS technology is designed for customers who need a simple Global Positioning System GPS chipset in their applications The Starter Kit is for evaluation of FirstGPS software performance The Starter Kit includes e A sample hardware board e A sample hardware environment including antenna power and serial communications e A sample Windows software application Microsoft Windows 95 Windows 98 Windows NT Windows 2000 e Sample source code for a typical application with examples of API calls e This manual in PDF format on the supplied CD Together these give a preliminary view of the hardware and software interfaces and provide the basis for a high level discussion of hardware and software integration issues FirstGPS Architecture With FirstGPS software the Position Velocity Time PVT solution is accessed directly by the host application through calls to an Application Programming Interface API This is a significant departure from past practice where the GPS function was usually a PVT serial solution that is a complete GPS receiver board that generated the Position Velocity Time PVT fix and then commu
45. e search algorithm assumes the oscillator is fliMaxOscOffset from nominal The larger the value the longer it takes to acquire Units are af f U8 ucOprtngDim Operating dimension For all the possible values refer to Operating Dimension page 53 U8 ucDgpsCfg Differential GPS configuration mode For all the possible values refer to DGPS Configuration Mode page 53 U8 ucDynamics Receiver modes For all the possible values refer to Dynamic Mode Flag page 53 U8 ucDgpsAgeLlimit DGPS correction age threshold in seconds U8 ucLpFixRate RF sequencing rates 44 FirstGPS Starter Kit User Guide npNavFixType Using the FirstGPS API A npNavFixType is used to store and report all pertinent information about the current fix Data Type Variable Description npFixChType tFixCh Channel dependent fix information npFixType tRawFix Raw position in latitude longitude Datum alt npFixType tFiltFix Filtered position in latitude longitude Datum alt DBL dbIDatumToMsIAIt Altitude conversion from Datum to MSL DBL dbIPosECEF 3 Raw ECEF position FLT filtVelECEF 3 Raw ECEF velocities DBL dblOscBias Oscillator bias in meters FLT fltOscFreq Oscillator frequency in meters second DBL dblTimeTag GPS time of fix in seconds The range is from 0 to 604799 U16 usWeekTag GPS week of fix npDopType tDop Dilution of precision numbers For more information refer to npDopType page 41 S16 sDatumIndex 0 WGS84 default U
46. e temperature measurement The temperature measurement is really the number of counts of an edge counter circuit on the measurement platform The frequency of the counter will vary as a function of temperature The NAV_TEMP_MEAS event will be generated when the temperature measurement has been completed Included Header File include npStdIface h Format npRetCode navGetTempParam npTempMeasType ptTempMeas FirstGPS Starter Kit User Guide Using the FirstGPS API A Output Parameter Data Type Parameter Description npTempMeasType ptlempMeas The npTempMeasType has all the temperature parameters for a measurement For more information refer to npTempMeasType page 438 Return Values Value Description NAV_OK A copy of temperature measurement data is retrieved successfully NAV_INCOMPLETE The measurement requested is not complete NAV_ERROR A copy of temperature measurement data is not retrieved successfully FirstGPS Starter Kit User Guide 77 A Using the FirstGPS API navStartTempMeas Start temperature measurement Description The function navStartTempMeas sends a message to the measurement platform to perform a temperature measurement over the number of milliseconds specified in the function call Included Header File include npStdIface h Format npRetCode navStartTempMeas U8 ucMsecInterval Input Parameter Data Type Parameter Description U8 ucMsecl
47. e the first fix Included Header File include npStdIface h Format npRetCode navGpsStart FLT fltTimeAccuracy U32 ulGpsMsec U16 usGpsWeek U8 ucTimeStatus Input Parameters Data Type Parameter Description FLT fltTimeAccuracy Accuracy of time value input in milliseconds 1 if unknown U32 ulGpgMsec Approximate GPS time of week in milliseconds U16 usGpsWeek GPS week number U8 ucTimeStatus A flag indicates whether or not the above values are accurate The value can be either TRUE indicating that the time is accurate or FALSE indicating that the time is approximate Ignore if fltTimeAccuracy is 1 Return Values Value Description NAV_OK The initialization of navigation platform is successful NAV_ERROR The initialization of navigation platform is not successful 80 FirstGPS Starter Kit User Guide Using the FirstGPS API A navPutinitPosition Input initial LLA position Description The navPutInitPosition function allows the user to enter a known position on startup to minimize the time needed for a first fix The initial position is an array of doubles in the order of latitude longitude and altitude The fltAccuFlag field determines whether or not the input parameters are accurate Included Header File include npStdIface h Format npRetCode navPutInitPosition DBL pdblPosLLA FLT fltAccuFlag Input Parameters Data Type Parameter Description DB
48. e two API functions navGpsStart page 80 and navGpsShutDown page 79 are provided for that purpose Before any other API calls can be made the AppTask must call navGpsStart page 80 once to power up the GPS engine In response to this call two events are generated NAV_POWER_ON_ACK The first event is generated immediately after the call to navGpsStart and indicates that a request to power up has been received and that the GPS engine is starting up NAV_START_UP_COMPLETE The second event is generated a few moments later to indicate that the FirstGPS library and the IO have successfully started and are running This may take up to 3 seconds depending on the hardware and RTOS After the second event has been received the AppTask may use other FirstGPS API functions to retrieve library data In addition any API calls that configure library components such as the receiver or filter configuration must also be called at this time if required 32 FirstGPS Starter Kit User Guide Software Integration 3 When GPS operation is not required the library can be shut down to decrease power consumption To power down the library the application must call navGpsShutDown page 79 In response to this call the NAV_READY_TO_SHUTDOWN event is generated as soon as the library is completely shut down It may take up to several seconds before this event is generated Polled vs Event Driven Data Collection The FirstGPS library pro
49. ed the event data structure is stored internally in a queue in the library In order for the application task to know which events have been generated a special API function navGetEvent page 63 is used to retrieve FirstGPS events This function blocks the calling task for example AppTask until an event is generated at which point the task is resumed In a typical application the AppTask runs in a simple loop calling navGetEvent continuously When an event is generated by the FirstGPS library the function returns the event information allowing the application task to call the API function corresponding to the generated event and process the data After the event specific processing is complete the application task calls navGetEvent again and repeats the loop Note Event driven data collection is the preferred method of using the FirstGPS API calls Trimble recommends that polled data collection be used mainly when responding to queries for library data For example when a New Position Fix Available event is generated the AppTask calls navGetLastFix page 66 to retrieve the newly generated position fix data The application should avoid scenarios where it constantly calls API functions such as navGetLastFix on its own scheduled by a timer or while running in an infinite loop For information on how to retrieve events properly refer to the description of the API function navGetEvent page 63 FirstGPS Starter Kit User Guide
50. ellite See Dilution of precision Time to First Fix Temperature Compensated Oscillator Temperature Compensated Crystal Oscillator Universal Time Coordinated Universal Coordinated Time See Dilution of precision Crystal as used in Figure 1 1 on page 5 for example 86 FirstGPS Starter Kit User Guide Index A ALM_PAGES_PRESENT 50 Almanac 23 46 Almanac status code 50 Almanac status flag 50 Antenna 12 Application Layer 9 Application port 26 Application settings 26 Applications Programming Interface 2 Azimuth 19 B BBRAM 21 26 59 C Channel status code 52 Channel tracking status 24 Clock 27 cName 49 Cold reset 21 Colossus RFIC 6 Configuration menus 25 CoolRISC 6 cSvUsed 42 75 D Data logging 26 Data types 38 Date function 17 dblBias 48 dblDatumToMslAlt 45 dblFreqOffset 48 74 dblOscBias 45 dbIPosECEF 45 dblPosLLA 43 dblTime 40 dblTimeTag 45 DGPS configuration mode 53 DGPS operating mode 52 DGPS_AUTO_OFF 52 DGPS_AUTO_ON 52 DGPS_CFG_AUTO 53 DGPS_CFG_OFF 53 DGPS_CFG_ONLY 53 DGPS_OFF 52 DGPS_ONLY 52 Digital Signal Processing 3 Dilution of precision 19 41 DIM_ISV 53 DIM_2D 53 DIM_2D_CLK_HOLD 53 DIM_3D 53 DIM_AUTO 53 DIM_DGPS_REF 53 DIM_OVERDET_CLK 53 DSP ASIC 3 FirstGPS Starter Kit User Guide 87 Index DYN_AIR 53 DYN_LAND 53 DYN_SEA 53 DYN_STATIONARY 53 DYN_UNDEFINED 53 Dynamic mode flag 53 E Elevation 19 Enumerated data types 50 EPH_DECODED 52 EP
51. ension mode For all the possible values and descriptions refer to Operating Dimension on page 53 U8 ucDgpsMode Differential GPS mode For all the possible values and descriptions refer to DGPS Operating Mode on page 52 U8 ucSatCnt Number of satellites in the constellation S8 cSvUsed N_CHANNELS A list of SVs in the constellation npDopType tDop Dilution of precision numbers For more information refer to noDopType page 41 42 FirstGPS Starter Kit User Guide npFixType Using the FirstGPS API npFixType is used to store fix data A Data Type Variable Description DBL FLT npErrorEstType dbIPosLLA 3 fltVelEnu 3 tErrorEst 0 Latitude in radians The range is from TT 2 to 7 2 1 Longitude in radians The range is from T to 7 2 Altitude above Datum ellipsoid in meters 0 East 1 North 2 Up velocities in meters second The range is from 0 0 to 300 0 Solution 1 sigma error estimate numbers For more information refer to npErrorEstType page 41 FirstGPS Starter Kit User Guide 43 A Using the FirstGPS API npNavConfigType npNavConfigType contains a set of parameters which maintains the configuration of a GPS receiver Data Type Variable Description FLT fltElevMask Elevation mask Radians 0 0 7 2 FLT fltAmuMask AMU mask FLT fltDopMask DOP mask FLT fltPdopSwitch PDOP 2D 3D switch level FLT fltMaxOscOffset Th
52. er to Oscillator Status Code page 54 U8 ucHaveFreqOffset Status flag indicating validity of drift For all possible values refer to Operating Dimension page 53 npTempMeasType npTempMeasType is a set of temperature measurement parameters Data Type Variable Description U8 ucMsecinterval The number of milliseconds over which the temperature measurement was made U32 ulMeasMsec The current GPS time when the temperature measurement was made U32 ulMeasCount The measured TCO frequency in counts ucMsecInterval This value varies with the temperature 48 FirstGPS Starter Kit User Guide npVersionTagType Using the FirstGPS API A npVersionTagType lists a complete description of a product version Data Type Variable Description S8 cName 18 Product name U8 ucMajor Major version number U8 ucMinor Minor version number U8 ucBeta Beta version 0 if this is a final release U8 ucMonth Month of release U8 ucDay Day of release U16 us Year Year of release npVersionType np VersionType stores the version number for the measurement platform firmware navigation platform API navigation platform software native RTOS and native processor For a detailed description refer to np VersionTagType page 49 Data Type Variable Description npVersionTaglype tMpFwVer Measurement platform version npVersionTaglype tNpApiVer Navigation platform API version npVersionTagType iNpSwVer Navigation platform
53. eter Description npNavConfigType ptNavConfig A pointer to a new receiver configuration structure Return Values Value Description NAV_OK The receiver configuration parameters are imported successfully NAV_ERROR The receiver configuration parameters are not imported successfully FirstGPS Starter Kit User Guide 73 A Using the FirstGPS API navPutOscFreqOffset Put oscillator drift offset Description navPutOscFreqOffset allows the user to override the startup value of the oscillator frequency offset This is of particular importance to those systems that do not have battery backed up RAM BBRAM The current oscillator offset can be obtained from the navGetOscStatus function Included Header File include npStdIface h Format npRetCode navPutOscFreqOffset DBL dbIFreqOffset FLT fltFreqSearch Input Parameters Data Type Parameter Description DBL dbIFregOffset New oscillator frequency offset will be imported into the navigation platform in meters second FLT fltFreqSearch The frequency to search around the dbiFreqOffset in meters second Return Values Value Description NAV_OK The new oscillator frequency offset has been entered successfully NAV_ERROR The new oscillator frequency offset has not been entered successfully 74 FirstGPS Starter Kit User Guide Using the FirstGPS API A navGetSvSelections Get satellite selection Description This function returns a l
54. etermine quickly if the receiver needs ephemeris data Almanac Specifies the current status of the almanac A field similar to the one described above is also available for the almanac to determine quickly if the receiver needs almanac data FirstGPS Starter Kit User Guide Using the FirstGPS API A Data Type Parameter Description U32 U32 U32 U8 U8 U8 U8 U8 ulEphStatus ulAlmPageStatus ulAlmHealthStatus ucPosStatus ucTimeStatus ucOscStatus ucMemStatus ucAlmStatus The ephemeris status from the navigation platform The least significant bit LSB represents the ephemeris status for satellite 1 and the most significant bit MSB represents satellite 32 The value 1 indicates that the ephemeris is present and that it is valid whereas 0 indicates that the ephemeris is not present or that it is invalid The almanac page status from the navigation platform The LSB represents the ephemeris status for satellite 1 and the MSB represents satellite 32 The value 1 indicates that the almanac has been collected whereas 0 indicates that the almanac has not been collected The almanac page being collected does not mean that the satellite is healthy See ulAlmHealthStatus below for health status information The almanac health status from the navigation platform The LSB represents the almanac status for satellite 1 and the MSB represents satellite 32 The value 1 indicates that the sate
55. formance evaluation of the FirstGPS platform running on the Microsoft Windows 95 98 NT or 2000 operating environment Running the FirstGPS Starter Kit for the First Time This section describes how to set up the FirstGPS Starter Kit The FirstGPS Monitor program is referred to as the GUT To set up the FirstGPS Starter Kit 1 Connect the motherboard to a 9 32 VDC power supply 2 Attach the antenna cable to the connector on the motherboard and place the antenna where over half the sky is visible Note Windows with reflective glass or wire mesh can sometimes block the GPS signal 3 Use an RS 232 cable to connect Port 1 on the motherboard to a serial COM port on your PC 4 Run the GUI The FirstGPS Starter Kit CD installs the GUI to your C Program Files Trimble FirstGPS folder 14 FirstGPS Starter Kit User Guide Using the Starter Kit 2 If this is the first time the program has been run the application settings window shown below appears Application Settings MPM Port Misc Settings Pot COM5 M Append port to logs I Syne PC Time to UTC Application Port I Load BBRAM on start Port come V Save BBRAM on exit I Smooth Dialog Resize Baud hd aud 3600 Clock 125 13 Parity None z Num Channels a Output TSIP Week epoch 1024 Cancel Be sure to select the correct application settings before running the MPM kit 1 Set the MPM Port to the name
56. g or press F1 To access the What s This Help click the question mark in the top right corner of a dialog box then click the relevant item Readme txt file A Readme txt file contains information added after the documentation was completed To read this file double click it or use a text editor to open it The installation program also copies this file into the program directory Release notes The release notes describe new features of the product information not included in the manual and any changes to the manual The release notes are provided as a doc file on the CD and are installed in the program directory typically C Program Files Trimble FirstGPS when you install the software Use a text editor to view the contents of the release notes ftp trimble com Use the Trimble FTP site to send files or to receive files such as software patches utilities service bulletins and FAQs Alternatively access the FTP site from the Trimble Web site at www trimble com support support htm Trimble training courses Consider a training course to help you use your GPS system to its fullest potential For more information visit the Trimble Web site at www trimble com support training htm FirstGPS Starter Kit User Guide About This Manual Technical Assistance If you have a problem and cannot find the information you need in the product documentation do one of the following Send an e mail to firstgps_suppo
57. helpful Which sections do you use the most What do you like best about the manual What do you like least about the manual Optional Name Company Address Telephone Fax Please mail to Trimble Navigation Limited 645 North Mary Avenue P O Box 3642 Sunnyvale CA 94088 3642 Alternatively email your comments and suggestions to ReaderFeedback trimble com All comments and suggestions become the property of Trimble Navigation Limited
58. ing the FirstGPS API A npDopType npDopType contains a set of DOP dilution of precision parameters Data Type Variable Description FLT fltPDOP Position DOP FLT fltHDOP Horizontal DOP FLT fltVDOP Vertical DOP FLT fltTDOP Time DOP npErrorEstType npErrorEstType stores the system estimate of error of the produced fix These are 1 sigma values and are computed based on the expected error from each satellite and the geometry of the constellation in use Data Type Variable Description FLT fIt3D Total position error in meters FLT fltHoriz Horizontal position error in meters FLT fltVert Vertical position error in meters FLT fltTime Time bias error in meters npFixChType npFixChType stores channel dependent fix data Data Type Variable Description FLT fltReserved N_CHANNELS 1 Reserved for future use S16 sCno N_CHANNELS CNO of SVs used in fix The range is 0 to 47 U8 ucSvUsed N_CHANNELS ID of satellites used U8 uclode N_CHANNELS IODE of satellites used U8 ucAmu5 N_CHANNELS AMU 5 of SVs used in fix The range is 0 16 5 80 FirstGPS Starter Kit User Guide 41 A Using the FirstGPS API npFixSvSelType npFixSvSelType describes the current constellation of satellites used in the current position fix Data Type Variable Description U8 ucStatus Satellite status code For all the possible values and descriptions refer to Satellite Status Code on page 57 U8 ucDimMode Operating dim
59. ist of satellites used for a position fix The structure npFixSvSelType has the current constellation of satellites used in doing a position fix It also contains modes of operation flags and DOP values Notice that a negative cSvUsed number indicates that an SV was not included for the position fix calculation because of poor integrity For detailed descriptions refer to npFixSvSelType page 42 Included Header File include npStdIface h Format npRetCode navGetSvSelections npFixSvSelType ptFixSvSel Output Parameter Data Type Parameter Description npFixSvSelType ptFixSvSel A pointer to a data structure which includes number of satellites DOPs and modes of operation Use the ucStatus field of the structure to determine the current status of the navigation platform For details refer to npFixSvSelType page 42 Return Values Value Description NAV_OK NAV_ERROR The npFixSvSelType structure has valid data The npFixSvSelType structure does not have valid data FirstGPS Starter Kit User Guide 75 A 76 Using the FirstGPS API navGetTempParams Get temperature data Description The function navGetTempParams gets the temperature data from the navigation platform The data contain the following information e The number of milliseconds over which the temperature was made e The time in ulMeasMsec when the navigation platform received the temperature measurement e Th
60. lling task until either an event has been generated or the timeout ITimeOut expired If an event has been retrieved successfully the function returns NAV_OK and updates pulEvent and pvEventData pointers with the retrieved event and its data FirstGPS Starter Kit User Guide 63 A 64 Using the FirstGPS API Trimble recommends that the application have a task dedicated exclusively to retrieving and processing FirstGPS events For example the entry point of such a task would be void eventHandlerTask void U32 ulEvent ulEventData Loop forever while 1 Retrieve the FirstGPS event if navGetEvent amp gtEventHandlerTask amp ulEvent amp ulEventData EVENT_WAIT_FOREVER EVENT_GET_FIRST NAV_OK processEvent ulEvent ulEventData Here sleep a little letting other tasks to complete This is optional and may not be required by the application Sleep 10 Note In the above example 1 gtEventHandlerTask is assumed to be a global variable of the task control block type relevant to a native RTOS 2 The timeout value in navGetEvent is specified as EVENT_WAIT_FOREVER This will suspend the event task until an event has been generated Trimble recommends this method for retrieving events 3 Using the method in 2 EVENT_GET_FIRST should be used for the ucGetFlag parameter This will retrieve the events in the order in which they were generated FirstGPS Starte
61. llite is unhealthy 0 indicates otherwise the satellite is healthy or information has not been collected yet The position status from the navigation platform For all possible values refer to Position Status Code page 56 The time status from the navigation platform For all possible values refer to Time Status Code page 57 The oscillator status from the navigation platform For all possible values refer to Oscillator Status Code page 54 The memory status from the navigation platform can be either zero or non zero where non zero indicates that the memory contents are valid and zero indicates that the contents are invalid The almanac status from the navigation platform For all possible values refer to Almanac Status Code page 50 FirstGPS Starter Kit User Guide 47 A Using the FirstGPS API npOscStatusType npOscStatusType is a set of parameters describing the oscillator The parameters ucHaveBias and ucHaveFreqOffset are flags indicating the current condition of the oscillator For all the possible values refer to Oscillator Status Code page 54 Data Type Parameter Description DBL dbiBias Oscillator bias in meters DBL dbIFregOffset Oscillator frequency offset in meters second FLT fltBiasUnc Oscillator bias uncertainty in meters FLT fltFreqOffsetUnc Oscillator frequency offset uncertainty in meters second U8 ucHaveBias Status flag indicating validity of bias For all possible values ref
62. nicated the PVT fix to the host application through a serial port The API based design offers considerably more flexibility for the applications designer along with benefits in terms of size power and cost 2 FirstGPS Starter Kit User Guide FirstGPS Starter Kit Overview 1 The FirstGPS architecture is built around three components designed by Trimble e Colossus Radio Frequency RF ASIC e IO Digital Signal Processing DSP ASIC e FirstGPS software library The Colossus and IO chips are the center of the GPS function hardware core The FirstGPS library is the software interface with the GPS function hardware core and it is linked into the customer s software application A complete FirstGPS implementation comprises the following components Power e Antenna and low noise amplifier LNA The GPS function hardware core e The host software application Application Layer and FirstGPS library l The FirstGPS software library is sometimes referred to as simply the FirstGPS library 2 The IO chip pronounced EEH ooh is named after the moon of Jupiter whose discovery along with the three other Galilean moons was one of the landmarks in the history of navigation By marking the Jovian lunar transits eclipses Galileo estimated there are three per day on average two navigators can easily synchronize their timepieces This established the first anywhere anytime time standard Since the measurement of time is eq
63. nt The rest of the tasks can loosely be grouped as navigation code These form a larger body of code heavy with floating position operations but with higher tolerance to latency In typical GPS board implementations all tasks are hosted in the same CPU even though they have significantly different characteristics In contrast the FirstGPS architecture hosts the signal processing function on the IO and the navigation function on a host CPU allowing the processor characteristics to be optimized for each function and reducing total system loading IO Interfaces The outputs of the IO tracking loops are sent via serial link to the host CPU where the FirstGPS navigation code resides There the raw outputs from IO are processed into range Doppler and orbit data information and then further processed into a PVT solution These results are made available through a fully featured FirstGPS API to the host application In the reverse direction IO receives tracking loop controls from the FirstGPS software via the serial link The serial link rate between IO and host CPU is typically 19200 baud FirstGPS Starter Kit User Guide 7 1 8 FirstGPS Starter Kit Overview The IO has a Pulse per Second PPS function One of the IO pins is held high for approximately 3 microseconds at the start of every UTC second An API call is available to apply a small time bias typically an advance of a few microseconds to account for cable lengths The I
64. of the COM port on the PC used to connect with the MPM 2 Select the Save BBRAM on exit check box This will provide a faster Time to First Fix TTFF 3 Set Clock to 12 504 MHz Set Num Channels to 12 5 Set Week epoch to 1024 This includes all dates between August 22 1999 and March 2019 To modify these or other application settings at a later time from the FirstGPS Monitor menu page 17 select Configure Settings FirstGPS Starter Kit User Guide 15 2 Using the Starter Kit Running the FirstGPS Starter Kit When the FirstGPS Monitor main window appears shown on page 17 the GPS engine is ready to start To launch the GPS engine FirstGPS library e Select Initialize Start GPS If the application fails to initialize a startup failed message is displayed in the status bar on the bottom left of the main window If this occurs please check that The COM port settings are correct in the application settings The serial cable is connected between Port 1 of the MPM and the PC s COM port The MPM kit is powered up with a correct DC power source To stop the GPS function after the GUI has been running e Select Initialize Stop GPS This shuts down the FirstGPS library and the MPM You can then exit the GUI Note If the GUI is still running when the MPM unit is disconnected from the power source you must restart the GUI application 16 FirstGPS Starter Kit User Guide Using the St
65. omplete and current 50 FirstGPS Starter Kit User Guide Using the FirstGPS API A The four bit positions in the byte indicate the presence of certain data 1 The bit with value 1 set means that the receiver has an almanac health page This page defines which satellites are present in the current GPS constellation 2 Ifthe receiver has an almanac health page and if it has an almanac page for each satellite which is declared present then the bit with value 2 will be set 3 Ifthe receiver has the UTC page then the bit with value 4 will be set 4 If the receiver has the IONO page then the bit with value 8 will be set FirstGPS Starter Kit User Guide 51 A Using the FirstGPS API Channel Status Code Define Value Description STATUS_RESET 0 Know nothing condition STATUS_TIME_KNOWN 1 MSEC ambiguity resolved STATUS_FREQ_LOCK 2 Delta phase range STATUS _PHASE_LOCK 4 Phase delta phase range STATUS_LOCK_POINT_KNOWN 8 Resolved 1 2 cycle STATUS_FRESH_MEAS 16 At least one measure in the last measured period measured period is the inverse of the measurement rate STATUS_GOOD_PARITY 32 At least 1 good parity result STATUS_VALID_MEAS 64 Measurement passes goodness checks STATUS_HEALTHY 128 Satellite data healthy Navigation Status Code Define Value Description EPH_DECODED 1 Ephemeris has been decoded EPH_GOOD 2 Ephemeris is good EPH_USED_IN_FIX 16 Used in the current position fix EPH_DGPS_C
66. r Kit User Guide Included Header File include npStdIface h Format Using the FirstGPS API A npRetCode navGetEvent void pvTaskId U32 pulEvent void pvEventData S32 TimeOut U8 ucGetFlag Input Parameters Data Type Parameter Description void pvTaskld A pointer to a task control block of the calling task 32 TimeOut A timeout value U8 ucGetFlag Indicates the event retrieval method Output Parameters Data Type Parameter Description U32 pulEvent A pointer to a variable to be updated with the event void pvEventData A pointer to a variable to be updated with data associated with the event Return Values Value Description NAV_OK The event is retrieved successfully NAV_ERROR The event is not retrieved successfully FirstGPS Starter Kit User Guide 65 A Using the FirstGPS API navGetLastFix Get last position fix information Description Gets a copy of the complete fix structure reflecting the last solution fix This contains various items including LLA and ECEF position velocity solutions both raw and filtered and their uncertainties clock bias clock offset list of satellites used issue of data ephemeris ODE and different mode flags The NAV_FIX_NEW event will be generated when a new position fix is available Included Header File include npStdIface h Format npRetCode navGetLastFix npNavFixType ptNavFix Output Parameter
67. r the possible values and description see Navigation Status Code page 52 U8 ucAmu5 SNR in units of 0 2 AMU per bit S16 sCno SNR in units of CNO The range is 0 to 47 U16 usReserved Reserved for future use U16 usMeasStatus Describes measurement status For all the possible values and descriptions see Channel Status Code page 52 FLT fItAzimuth Azimuth in radians FLT fltElev Elevation in radians FirstGPS Starter Kit User Guide 39 A Using the FirstGPS API npCompTimeType npCompTimeType defines a minimal set of clock time fields that can be used to do conversions between GPS time and SCOUNT Data Type Variable Description U32 ulMsecs GPS time of week in milliseconds U16 usWeeks GPS week number U16 usRefScount SCOUNT value U8 ucStatus Status of the time For all the possible values and descriptions refer to Time Status Code page 57 npDgpsCorrType npDgpsCorrType describes the differential correction block Data Type Variable Description U8 ucSvld Satellite ID U8 uclod Issue of data DBL dblTime Correct time tag GPS time of week in seconds U32 ulTimeOfReception Time of reception GPS time of week in milliseconds FLT fltPrc Pseudorange correction in meters FLT fltRrc Range rate correction in meters second FLT fltRrcDot Acceleration correction in meters second FLT fltPrcErrEst 1 sigma pseudorange correction error estimate in meters 40 FirstGPS Starter Kit User Guide Us
68. rt trimble com Contact support at one of the numbers listed in the front section of this manual Request technical support using the Trimble Web site at www trimble com support support htm Your Comments Your feedback about the supporting documentation helps us to improve it with each revision To forward your comments do one of the following Send an e mail to ReaderFeedback trimble com Complete the Reader Comment Form at the back of this manual and mail it according to the instructions at the bottom of the form If the reader comment form is not available send comments and suggestions to the address in the front of this manual Please mark it Attention Documentation Group FirstGPS Starter Kit User Guide xi About This Manual xii Document Conventions The document conventions are as follows Convention Definition Italics Helvetica Narrow Helvetica Bold Select Italics Italics Identifies software menus menu commands dialog boxes and the dialog box fields Represents messages printed on the screen Identifies a software command button or represents information that you must type in a software screen or window Identifies the sequence of menus commands or dialog boxes that you must choose in order to reach a given screen Is an example of a hardware function key that you must press on a personal computer PC If you must press more than one of these at the same tim
69. rter Kit User Guide Using the Starter Kit 2 DOPs DOPs is the abbreviation for Dilution Of Precision numbers These numbers are roughly associated with accuracy the larger the numbers are the less accurate the fix is The two most useful numbers are Horizontal DOP HDOP proportional to horizontal position accuracy and Vertical DOP VDOP Position DOP PDOP is for three dimensional position accuracy and Time DOP TDOP is used for time accuracy For more information refer to navGetLastFix page 66 and to the Glossary Firmware Info Firmware Info is the firmware version of the FirstGPS library and the firmware version of the MPM For more information refer to navGetNavVersion page 69 Satellite Data Satellite Data is the current satellite tracking information for each IO channel e SV satellite identifier PRN If the PRN is against a green background that satellite is usable for fixes e AMU the signal strength in AMUs e Az azimuth e Eley elevation in degrees if known When elevation is unknown the value 90 or 90 is displayed For more information refer to navGetChStatus page 60 and navGetSvSelections page 75 FirstGPS Starter Kit User Guide 19 2 Using the Starter Kit Program Status This section of the window has no title It is located at the bottom of the window Program Status indicates Status of the serial connection between PC and MPM e Status of the FirstGPS library e
70. ted by the navigation platform U32 pulSize A pointer to U32 that has the size of the entire BBRAM in bytes This field is also updated by the navigation platform Return Values Value Description NAV_OK The BBRAM address is retrieved successfully NAV_ERROR The BBRAM address is not retrieved successfully FirstGPS Starter Kit User Guide 59 A Using the FirstGPS API navGetChStatus Get satellite tracking status Description This function provides information azimuth elevation AMU and so on of the satellites currently being tracked from the navigation platform The data structure npAlIChStatus Type has two fields GPS time and an array of npChStatusType N_CHANNELS with each entry corresponding to a channel The data type npChStatusType contains all the tracking information for a channel Included Header File include npStdIface h Format npRetCode navGetChStatus npAllChStatusType ptAllChStatus Output Parameter Data Type Parameter Description npAllChStatus Type ptAllChStatus A pointer to an application structure which will be updated by the navigation platform For descriptions of each sub field refer to npAllChStatusType page 39 and npChStatusType page 39 Return Values Value Description NAV_OK The tracking information is retrieved successfully NAV_ERROR The tracking information is not retrieved successfully 6 O FirstGPS Starter Kit User Guide Using the FirstGPS API A n
71. ted successfully NAV_ERROR The GPS time is not imported successfully FirstGPS Starter Kit User Guide 71 A Using the FirstGPS API navPutDgpsCorrParams Put differential correction information Description This function puts a copy of all the current differential correction parameters into the navigation platform s database Included Header File include npStdIface h Format npRetCode navPutDgpsCorrParams npDgpsCorrType ptDgpsCorr U8 ucCount U8 ucClearFlag Input Parameters Data Type Parameter npDgpsCorrType ptDgpsCorr U8 ucCount U8 ucClearFlag Description A pointer to an array which contains the values to the navigation platform For complete details refer to npDgpsCorrType page 40 Indicates number of valid entries Boolean TRUE clears all previous entries FALSE does not clear previous entries Return Values Value Description NAV_OK The differential correction parameters are imported successfully NAV_ERROR The differential correction parameters are not imported successfully 72 FirstGPS Starter Kit User Guide Using the FirstGPS API A navPutNavConfig Put receiver settings Description This function imports a copy of the current GPS configuration into the navigation platform Included Header File include npStdIface h Format npRetCode navPutNavConfig npNavConfigType ptNavConfig Input Parameter Data Type Param
72. ugh a low pass filter off chip brought back in to a limiting amplifier and then sampled before being passed onto the IO DSP The sampling frequency input to the Colossus by the IO DSP is the external LO frequency divided by four For a 12 504 MHz system the sampling frequency would be 3 126 MHz Note Keep all of the above frequencies in mind for EMI purposes when doing system design All three voltages listed in Power page 5 are supplied to Colossus to feed the separate sections of the IC VCC_RF for the RF conversion VCC_DIG for the digital dividers and VCC_OUT for the Z and Q output buffers IO DSP The GPS signal processing function is performed by the IO DSP This ASIC contains the GPS correlation channels and a small CoolRISC processor core with its own RAM and ROM The CooIRISC runs the tracking loop code that controls the correlators FirstGPS Starter Kit User Guide FirstGPS Starter Kit Overview 1 The FirstGPS architecture is different from most GPS receiver architectures In all modern GPS architectures the software resides in a multitasking environment The tasks perform a variety of functions including e tracking loop control e measurement conditioning e position computations e navigation data decoding The highest priority task is the signal processing code tracking loops This code although it has a small code footprint has a very high interrupt rate up to 2000 Hz with a stringent latency requireme
73. uide FirstGPS Starter Kit Overview 1 Motherboard The MPM interface motherboard includes a 9 to 32 VDC input software switching power supply that provides a regulated 3 3 VDC to the MPM receiver It also converts the TTL level I O to RS 232 for a direct interface to the computer The motherboard provides an open collector interface for the PPS The input voltage must be between 9 VDC and 32 VDC and is input to the board through a 3 pin circular connector of which only two pins are used Supplying power outside the specified input range will damage the board Although there are two communication ports on the motherboard only one is available for use by the MPM Port 1 The pin identities for PORT 1 are Pin Function NC TX RX NC GND NC NC NC PPS Oo WAN OAR OO N gt Note Due to the open collector interface through the 9 pin RS 232 port the polarity of the PPS signal is inverted The pulse is a 4 us negative going pulse with the falling edge synchronized to UTC When removed from the motherboard the receiver provides a positive going TTL level pulse with the rising edge synchronized to UTC FirstGPS Starter Kit User Guide 11 1 FirstGPS Starter Kit Overview Antenna The Antenna supplied with the Starter Kit is a 3 3 VDC patch antenna with integrated cable and connector for terminating to the interface unit This is an active antenna with 28 dB of gain The MPM requires approximately 10 d
74. uivalent to the measurement of longitude observation of the Jovian moons allowed absolute accurate positioning for the first time in the history of man For a more detailed account of Galileo s discovery and the invention of the chronometer which eclipsed his discovery see Longitude The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time Dava Sobel 1995 FirstGPS Starter Kit User Guide 3 1 FirstGPS Starter Kit Overview Input Output Interface The Starter Kit contains a complete sample FirstGPS implementation described in Starter Kit Components page 9 The sample hardware core is the Measurement Platform Module MPM described on page 9 The sample host software application is a Windows based program described in detail in Chapter 2 Using the Starter Kit The sample power interface antenna interface and the serial interface between MPM and host CPU are provided by the motherboard housing the MPM FirstGPS Hardware Core There are two FirstGPS ASICs an RFIC Colossus and a DSP ASIC IO These two chips combined with a voltage regulator a Surface Acoustic Wave SAW filter and a crystal oscillator create the GPS function hardware core Figure 1 1 shows the block diagram of this hardware core The MPM in the FirstGPS Starter Kit is a sample board layout of the GPS hardware component The MPM board is described in Measurement Platform Module MPM page 9 Layout depends upon the customer
75. vides facilities for both polled and event driven data collection e Polled data collection involves the AppTask periodically calling FirstGPS API functions to retrieve various data from the library position fix almanac status satellite data and so on The AppTask assumes the responsibility of scheduling data collection This type of data collection is useful when responding to manual requests for data such as through a serial cable keyboard or touch screen interface Polled data is also useful when the AppTask has a timer based scheduling mechanism to periodically collect store and or process the data available through the API e Event driven data collection allows the AppTask to quickly retrieve data through the API as soon as the data is generated by FirstGPS The library generates an event whenever significant new data is available while the library is running For example every time the library computes a new position velocity fix a New Position Fix Available event is generated The library can generate several different types of events The Standard FirstGPS Events table on page 58 lists all of them Based on the type of event generated the AppTask calls a corresponding API function to retrieve data associated with the event The Event vs API Table page 35 lists FirstGPS events and the corresponding API function calls FirstGPS Starter Kit User Guide 33 3 34 Software Integration Whenever an event is generat
76. y one usable satellite SCODE_2SVS 7 Only two usable satellites SCODE_3SVS 8 Only three usable satellites SCODE_DCORR_GEN 9 Differential corrections SCODE_OVERDET_CLK 10 Over determined clock Time Status Code The time status flag has the following valid states Only the highest state should be considered valid for setting the application s real time clock Define Value Description T_STATUS NONE 0 Time is unknown T_STATUS PROBLEM 1 Error detected Now being fixed T_STATUS APPX 2 Time is good to a few seconds from outside the receiver T_STATUS_ SET 3 Time is good to 10 msecs from tracking one satellite T_STATUS_BIAS_ KNOWN 4 Time is good to 1 us from a position fix npTimeStatusType is the type that enumerates the above constants FirstGPS Starter Kit User Guide 57 A Using the FirstGPS API Standard FirstGPS Events The following lists all of the standard events that the library could possibly generate For example the event NAV_FIX_NEW indicates that a new position fix has been generated Define Value Description NAV_FIX_NEW 10 New solution fix NAV_NO_FIX_NEW 11 Incapable of producing new fix NAV_TRK_SELECTION_NEW 12 New SV tracking selection NAV_FIX_SV_SEL_NEW 13 New SV fix selection NAV_REF_DCORR_NEW 15 Newly generated differential correction NAV_POWER_ON_ACK 20 Received request to turn on the FirstGPS NAV_START_UP_COMPLETE 21 NAV_READY_TO_ SHUTDOWN 22 NAV_START_UP_ FAILED 25
77. ypes function descriptions and so on Examples Refer to the sample application source code on the CD ROM shipped with your Starter Kit The examples illustrate how to use the API calls FirstGPS API Simple Data Types The table below describes all the simple data types defined within the Navigation Platform Defined Data Type Description S8 Signed 8 bits integer U8 Unsigned 8 bits integer S16 Signed 16 bits integer U16 Unsigned 16 bits integer 32 Signed 32 bits integer U32 Unsigned 32 bits integer FLT 4 bytes single precision floating point DBL 8 bytes double precision floating point BOOLEAN 1 byte Boolean value 38 FirstGPS Starter Kit User Guide Using the FirstGPS API A FirstGPS API Navigation Data Types The following subsections list all the data structures used for the Navigation platform All bit field descriptions assume the convention that the least significant bit LSB the first bit is bit 0 npAllChStatusType npAllChStatus Type is used to report the tracking status of all channels Data Type Variable Description U32 ulGpsTowMsec GPS time of week in milliseconds npChStatusType tChStatus N_CHANNELS Individual satellite tracking status For details refer to noChStatusType in the table below npChStatusType npChStatusType describes the tracking status for a channel Data Type Variable Description U8 ucSvid SV prn number U8 ucNavStatus Describes navigation status Fo

Trimble Outdoors 44326-00-ENG GPS Receiver User Manual

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