Trimble Outdoors GPS Receiver 44326 00 ENG User Manual

FirstGPSStarter Kit  
User Guide  
Version 1.0  
Part Number 44326-00-ENG  
Revision A  
March 2001  
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Warranty Exclusions and Disclaimer  
TRIMBLE NAVIGATION LIMITED IS NOT  
RESPONSIBLE FOR THE OPERATION OR  
FAILURE OF OPERATION OF GPS  
SATELLITES OR THE AVAILABILITY OF  
GPS SATELLITE SIGNALS.  
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; (ii) 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).  
Limitation of Liability  
TRIMBLES 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 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  
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-ISAND  
WITHOUT EXPRESS OR IMPLIED WARRANTY  
OF ANY KIND BY EITHER TRIMBLE  
INCIDENTAL DAMAGES, THE ABOVE  
LIMITATION MAY NOT APPLY TO YOU.  
NAVIGATION LIMITED OR ANYONE WHO 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.  
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About This Manual  
Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . x  
1
Measurement Platform Module (MPM) . . . . . . . . . . . . . . 9  
2
Running the FirstGPS Starter Kit for the First Time . . . . . . . . . . 14  
Running the FirstGPS Starter Kit . . . . . . . . . . . . . . . . . . . . 16  
FirstGPS Monitor Main User Interface . . . . . . . . . . . . . . . . . 17  
Time [GPS]. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17  
ENU Velocity [filt] . . . . . . . . . . . . . . . . . . . . . . . . 18  
FirstGPS Starter Kit User Guide  
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Configure Menu . . . . . . . . . . . . . . . . . . . . . . . . . 25  
3
Software Integration  
A
npChStatusType . . . . . . . . . . . . . . . . . . . . . . . . . 39  
npCompTimeType . . . . . . . . . . . . . . . . . . . . . . . . 40  
npDgpsCorrType . . . . . . . . . . . . . . . . . . . . . . . . . 40  
npDopType . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41  
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Standard FirstGPS Events . . . . . . . . . . . . . . . . . . . . 58  
FirstGPS API - Return Types . . . . . . . . . . . . . . . . . . . . . . 58  
FirstGPS API - Function Descriptions . . . . . . . . . . . . . . . . . 59  
navGetBbAddr . . . . . . . . . . . . . . . . . . . . . . . . . . 59  
navGetChStatus . . . . . . . . . . . . . . . . . . . . . . . . . 60  
FirstGPS Starter Kit User Guide vii  
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About This Manual  
Welcome to the FirstGPS Starter Kit User Guide. This manual  
describes how to install, set up, and use the FirstGPSApplication  
Programming Interface (API).  
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  
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About This Manual  
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 dialog, or  
press [F1]. To access the Whats 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  
x
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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:  
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:  
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.  
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Document Conventions  
The document conventions are as follows:  
Convention  
Definition  
Italics  
Identifies software menus, menu commands,  
dialog boxes, and the dialog box fields.  
Represents messages printed on the screen.  
Helvetica Narrow  
Helvetica Bold  
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.  
Select Italics / Italics’  
[Ctrl]  
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  
time, this is represented by a plus sign, for  
example, [Ctrl]+[C].  
xii FirstGPS Starter Kit User Guide  
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C H A P T E R  
1
1
FirstGPS Starter KitOverview  
In this chapter:  
Purpose of the Starter Kit  
FirstGPS Architecture  
Starter Kit Components  
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1
FirstGPS Starter Kit Overview  
1.1  
Purpose of the Starter Kit  
FirstGPStechnology 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:  
A sample hardware board  
A sample hardware environment, including antenna, power, and  
serial communications  
A sample Windows software application (Microsoft®  
Windows 95 / Windows 98 / Windows NT / Windows 2000)  
Sample source code for a typical application with examples of  
API calls  
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.  
1.2  
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  
communicated 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
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FirstGPS Starter Kit Overview  
1
The FirstGPS architecture is built around three components designed  
by Trimble:  
ColossusRadio Frequency (RF) ASIC  
IO Digital Signal Processing (DSP) ASIC  
1
FirstGPS software library  
2
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 customers  
software application.  
A complete FirstGPS implementation comprises the following  
components:  
Power  
Antenna and low-noise amplifier (LNA)  
The GPS function hardware core  
The host software application (Application Layer and  
FirstGPS library)  
1.  
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  
equivalent 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 Galileos 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  
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1
FirstGPS Starter Kit Overview  
1.2.1  
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 chipscombined with a voltage regulator, a Surface  
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 customers application. Proper board layout is crucial to good  
RF performance.  
4
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FirstGPS Starter Kit Overview  
1
BBI  
FILT  
BBQ  
FILT  
V_RF  
Vcc  
LI BLOCK  
RF+  
RF-  
Fr  
Matching  
Network  
SAW  
FILTER  
Colossus  
RF ASIC  
12.504 MHZ  
XTAL OSC  
RF IN  
Q
I
Fs Fr  
V_RF  
TxD  
RxD  
PPS  
VOLTAGE  
Vcc  
IO  
REGULATOR V_CORE  
DSP ASIC  
and  
COOLRISC  
TEMP  
SENSE  
Figure 1.1  
Colossus / IO Block Diagram  
Power  
The hardware core requires three voltages:  
Hardware Core  
VCC  
Voltage  
3.3 ±0.3 VDC  
3.0 ±0.3 VDC  
2.0 ±0.2 VDC  
V_RF  
V_CORE  
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  
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1
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 I and Q bits are  
passed through 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 I 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 CoolRISC runs the  
tracking loop code that controls the correlators.  
6
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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:  
tracking loop control  
measurement conditioning  
position computations  
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  
requirement. 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  
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1
FirstGPS Starter Kit Overview  
The IO has a Pulse-per-Second (PPS) function. One of the IO pins is  
held high for approximately 5 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 IO 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.  
1.2.2  
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  
customers 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,  
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.  
Initialize the receiver with non-volatile memory and current  
time, if available.  
Change receiver control parameters (satellite masks,  
DGPS corrections).  
Fetch current receiver status.  
Fetch the most recent PVT solution.  
Fetch ancillary data (for example, signal strengths).  
Stop the GPS function.  
8
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FirstGPS Starter Kit Overview  
1
1.2.3  
Application Layer  
The term Application Layer is used to describe 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.  
1.3  
Starter Kit Components  
1.3.1  
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
2
3
4
No Connect  
5
6
7
8
RXD  
Power  
PPS  
TXD  
SP_EN (Serial Port Enable)  
GND  
VCC_Ant (power for 5 V antenna)  
FirstGPS Starter Kit User Guide  
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1
FirstGPS Starter Kit Overview  
Figure 1.2 shows the top layout of Trimbles MPM assembly:  
Figure 1.2  
Top MPM Assembly Layout  
Figure 1.3 shows the bottom layout of Trimbles MPM assembly:  
Figure 1.3  
Bottom MPM Assembly Layout  
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FirstGPS Starter Kit Overview  
1
1.3.2  
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  
1
2
3
4
5
6
7
8
9
TX  
RX  
NC  
GND  
NC  
NC  
NC  
PPS  
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 µs  
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.  
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1
FirstGPS Starter Kit Overview  
1.3.3  
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 dB to 14 dB of gain at the antenna connector on  
board for best performance.  
1.3.4  
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).  
1.3.5  
Software  
See Chapter 2, Using the Starter Kit.  
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C H A P T E R  
2
2
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  
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2
Using the Starter Kit  
2.1  
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 performance evaluation  
of the FirstGPS platform running on the Microsoft Windows 95, 98,  
NT or 2000 operating environment.  
2.2  
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 GUI.)  
To set up the FirstGPS Starter Kit:  
1. Connect the motherboard to a 932 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.  
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Using the Starter Kit  
2
If this is the first time the program has been run, the application  
settings window shown below appears.  
Be sure to select the correct application settings before running the  
MPM kit:  
1. Set the MPM Port to the name 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.  
4. 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.  
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2.3  
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):  
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 PCs 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:  
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.  
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2.4  
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  
is communicating with the MPM kit, these sections are updated  
dynamically with current GPS information.  
2.4.1  
Time [GPS]  
The Time panel displays the following, relative to GPS or UTC  
depending on the output options. (Refer to Timing Output, page 23.)  
Time the day of the week, and time in hours: minutes: seconds  
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.  
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2.4.2  
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.  
2.4.3  
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.  
2.4.4  
Receiver Status  
Receiver Status displays current receiver information:  
Mode the operating mode: 2D or 3D, Automatic or Manual  
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 & current when the almanac collection  
has been completed. For more information, refer to navGetNavStatus,  
page 68, and navGetSvSelections, page 75.  
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2.4.5  
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.  
2.4.6  
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.  
2.4.7  
Satellite Data  
Satellite Data is the current satellite tracking information for each  
IO channel:  
SV satellite identifier (PRN). If the PRN is against a green  
background, that satellite is usable for fixes.  
AMU the signal strength (in AMUs)  
Az. azimuth  
Elev. 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.  
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2.4.8  
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  
Status of the FirstGPS library  
Time since power-up  
Name of the COM port on the PC  
2.5  
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.  
2.5.1  
2.5.2  
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.  
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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 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.  
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2.5.3  
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.  
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.  
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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 / 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 ICD-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 npNavStatusType,  
ulAlmHealthStatus parameter on page 47.  
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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.  
Ionosphere Info  
Select View / Ionosphere Info to display GPS data for the ionospheric  
model data page. Refer to the ICD-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-GPS-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  
Oscillator Offset  
Select View / Oscillator Offset to display the MPMs 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.  
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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 IOs temperature sensor reports.  
For more information, refer to navStartTempMeas, page 78 and  
navGetTempParams, page 76.  
2.5.4  
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 / 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.  
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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 system data  
such as:  
the almanac  
ephemeris  
UTC  
IONO(sphere) information  
Loading the current BBRAM file allows for faster TTFF.  
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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.  
Save BBRAM on exit This option enables the generation of the  
BBRAM file as described in the previous paragraph.  
Smooth Dialog Resize This option enables a smooth slide-out  
effect when various GUI dialog boxes are displayed.  
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.  
Week Epoch This option enables selection of the week epoch  
number, which is the number of 1024 week periods since  
6 January 1980.  
2.5.5  
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.  
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TTFF Statistics  
Select Tools / TTFF 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.  
2.5.6  
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).  
2.5.7  
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.  
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2.6  
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 FirstGPS 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.  
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C H A P T E R  
3
3
In this chapter:  
Overview  
Power-Up and Power-Down  
Polled vs. Event-Driven Data Collection  
Event vs. API Table  
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Software Integration  
3.1  
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.  
3.2  
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  
AppTasks responsibility to start up and shut down the FirstGPS  
engine as required. The 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.  
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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.  
3.3  
Polled vs. Event-Driven Data Collection  
The FirstGPS library provides facilities for both polled and event-  
driven data collection.  
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.  
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.  
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Whenever an event is generated, 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 .  
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3.4  
Event vs. API Table  
EVENT DESCRIPTION  
EVENT ID  
API  
New position/velocity fix  
available  
NAV_FIX_NEW  
navGetLastFix (page 66)  
No new fix available  
NAV_NO_FIX_NEW  
n/a  
New satellite tracking  
selection  
NAV_TRK_SELECTION_NEW  
navGetChStatus (page 60)  
New satellite fix  
selection available  
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  
navGetSvSelections  
(page 75)  
New differential  
correction available  
navGetDgpsCorrParams  
(page 62)  
Acknowledge to a  
request to start GPS  
navGpsStart (page 80)  
navGpsStart (page 80)  
navGpsShutDown (page 79)  
navGpsStart (page 80)  
FirstGPS library  
successfully started  
FirstGPS library  
successfully shut down  
FirstGPS library failed  
to initialize and start  
New temperature  
measurement data  
navGetTempParams  
(page 76)  
FirstGPS library fatal  
error generated  
NAV_FATAL_ERROR  
n/a  
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A P P E N D I X  
A
A
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  
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Using the FirstGPS API  
1.1  
Overview  
This appendix describes the FirstGPS API data types, return types,  
function descriptions, and so on.  
1.2  
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.  
1.3  
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.  
Signed 16 bits integer.  
S16  
U16  
Unsigned 16 bits integer.  
Signed 32 bits integer.  
S32  
U32  
Unsigned 32 bits integer.  
4 bytes single-precision floating point.  
8 bytes double-precision floating point.  
1 byte Boolean value.  
FLT  
DBL  
BOOLEAN  
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1.4  
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.  
1.4.1  
npAllChStatusType  
npAllChStatusType is used to report the tracking status of all  
channels.  
Data Type  
Variable  
Description  
U32  
ulGpsTowMsec  
tChStatus[N_CHANNELS]  
GPS time of week in milliseconds.  
npChStatusType  
Individual satellite tracking status. For  
details, refer to npChStatusType in the  
table below.  
1.4.2  
npChStatusType  
npChStatusType describes the tracking status for a channel.  
Data Type  
Variable  
ucSvId  
Description  
U8  
U8  
SV prn number.  
ucNavStatus  
Describes navigation status. For the  
possible values and description, see  
Navigation Status Code, page 52.  
U8  
ucAmu5  
sCno  
SNR in units of 0.2 AMU per bit.  
S16  
SNR in units of CNO. The range is  
0 to 47.  
U16  
U16  
usReserved  
Reserved for future use.  
usMeasStatus  
Describes measurement status. For all  
the possible values and descriptions,  
see Channel Status Code, page 52.  
FLT  
FLT  
fltAzimuth  
fltElev  
Azimuth in radians.  
Elevation in radians.  
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1.4.3  
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  
U16  
U16  
U8  
ulMsecs  
GPS week number.  
SCOUNT value.  
usWeeks  
usRefScount  
ucStatus  
Status of the time. For all the possible  
values and descriptions, refer to Time  
Status Code, page 57.  
1.4.4  
npDgpsCorrType  
npDgpsCorrType describes the differential correction block.  
Data Type  
U8  
Variable  
ucSvId  
ucIod  
Description  
Satellite ID.  
Issue of data.  
U8  
DBL  
dblTime  
Correct time tag; GPS time of week in  
seconds.  
U32  
ulTimeOfReception  
Time of reception; GPS time of week in  
milliseconds.  
FLT  
FLT  
fltPrc  
fltRrc  
Pseudorange correction in meters.  
Range rate correction in  
meters/second.  
FLT  
FLT  
fltRrcDot  
Acceleration correction in  
meters/second .  
2
fltPrcErrEst  
1-sigma pseudorange correction error  
estimate in meters.  
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1.4.5  
npDopType  
npDopType contains a set of DOP (dilution of precision) parameters.  
Data Type  
Variable  
fltPDOP  
fltHDOP  
fltVDOP  
fltTDOP  
Description  
Position DOP.  
Horizontal DOP.  
Vertical DOP.  
Time DOP.  
FLT  
FLT  
FLT  
FLT  
1.4.6  
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  
FLT  
Variable  
flt3D  
Description  
Total position error in meters.  
Horizontal position error in meters.  
Vertical position error in meters.  
Time bias error in meters.  
FLT  
fltHoriz  
fltVert  
FLT  
FLT  
fltTime  
1.4.7  
npFixChType  
npFixChType stores channel-dependent fix data.  
Data Type  
FLT  
Variable  
Description  
fltReserved[N_CHANNELS+1]  
sCno[N_CHANNELS]  
Reserved for future use.  
S16  
CNO of SVs used in fix. The range is  
0 to 47.  
U8  
U8  
U8  
ucSvUsed[N_CHANNELS]  
ucIode[N_CHANNELS]  
ucAmu5[N_CHANNELS]  
ID of satellites used.  
IODE of satellites used.  
AMU*5 of SVs used in fix. The range is  
0-16*5=80.  
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1.4.8  
npFixSvSelType  
npFixSvSelType describes the current constellation of satellites used  
in the current position fix.  
Data Type  
Variable  
Description  
U8  
U8  
U8  
U8  
ucStatus  
Satellite status code. For all the  
possible values and descriptions, refer  
ucDimMode  
ucDgpsMode  
ucSatCnt  
Operating dimension mode. For all the  
possible values and descriptions, refer  
to Operating Dimension on page 53.  
Differential GPS mode. For all the  
possible values and descriptions, refer  
to, DGPS Operating Mode on page 52.  
Number of satellites in the  
constellation.  
S8  
cSvUsed [N_CHANNELS]  
tDop  
A list of SVs in the constellation.  
npDopType  
Dilution of precision numbers. For more  
information, refer to npDopType,  
page 41.  
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1.4.9  
npFixType  
npFixType is used to store fix data.  
Data Type  
Variable  
Description  
DBL  
dblPosLLA[3]  
[0]Latitude in radians. The range is  
from π/2 to +π/2.  
[1]Longitude in radians. The range is  
from π to +π.  
[2]Altitude above Datum ellipsoid  
in meters.  
FLT  
fltVelEnu[3]  
tErrorEst  
[0]East.  
[1]North.  
[2]Up velocities  
in meters/second. The range is from  
0.0 to +300.0.  
npErrorEstType  
Solution 1-sigma error estimate  
numbers. For more information, refer  
to npErrorEstType, page 41.  
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1.4.10  
npNavConfigType  
npNavConfigType contains a set of parameters which maintains the  
configuration of a GPS receiver.  
Data Type  
Variable  
Description  
FLT  
FLT  
FLT  
FLT  
FLT  
fltElevMask  
fltAmuMask  
fltDopMask  
fltPdopSwitch  
fltMaxOscOffset  
Elevation mask. (Radians 0.0 π/2).  
AMU mask.  
DOP mask.  
PDOP 2D/3D switch level.  
The search algorithm assumes the  
oscillator is +/- fltMaxOscOffset from  
nominal. The larger the value, the  
U8  
U8  
U8  
ucOprtngDim  
ucDgpsCfg  
Operating dimension. For all the  
possible values, refer to Operating  
Dimension, page 53.  
Differential GPS configuration mode.  
For all the possible values, refer to  
DGPS Configuration Mode, page 53.  
ucDynamics  
Receiver modes. For all the possible  
values, refer to Dynamic Mode Flag,  
page 53.  
U8  
U8  
ucDgpsAgeLlimit  
ucLpFixRate  
DGPS correction age threshold in  
seconds.  
RF sequencing rates.  
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1.4.11  
npNavFixType  
npNavFixType is used to store and report all pertinent information  
about the current fix.  
Data Type  
Variable  
Description  
npFixChType  
npFixType  
npFixType  
DBL  
tFixCh  
Channel dependent fix information.  
Raw position in latitude, longitude, Datum alt.  
Filtered position in latitude, longitude, Datum alt.  
Altitude conversion from Datum to MSL.  
Raw ECEF position.  
tRawFix  
tFiltFix  
dblDatumToMslAlt  
dblPosECEF[3]  
fltVelECEF[3]  
dblOscBias  
fltOscFreq  
dblTimeTag  
DBL  
FLT  
Raw ECEF velocities.  
DBL  
Oscillator bias in meters.  
FLT  
Oscillator frequency in meters/second.  
DBL  
GPS time of fix in seconds. The range is from 0 to  
604799.  
U16  
usWeekTag  
tDop  
GPS week of fix.  
npDopType  
Dilution of precision numbers. For more  
information, refer to npDopType, page 41.  
S16  
U8  
sDatumIndex  
ucNumSvsUsed  
ucStatus  
0 = WGS84 = default.  
Number of SVs used.  
U8  
Indicates the validity status of this fix. For more  
information, refer to Position Fix Status, page 55.  
U8  
U8  
ucSource  
Indicates the source of this position fix. For more  
information, refer to Position Fix Source, page 54.  
ucDgpsFlag  
Differential GPS status. For more information,  
refer to Position Fix DGPS Status, page 55.  
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1.4.12  
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 determine 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.  
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Data Type  
Parameter  
Description  
U32  
ulEphStatus  
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.  
U32  
ulAlmPageStatus  
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.  
U32  
ulAlmHealthStatus  
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 satellite is unhealthy; 0  
indicates otherwise (the satellite is healthy or  
information has not been collected yet).  
U8  
U8  
U8  
ucPosStatus  
ucTimeStatus  
ucOscStatus  
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.  
U8  
U8  
ucMemStatus  
ucAlmStatus  
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 .  
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1.4.13  
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  
dblBias  
Description  
DBL  
DBL  
Oscillator bias in meters.  
dblFreqOffset  
Oscillator frequency offset in  
meters/second.  
FLT  
FLT  
fltBiasUnc  
Oscillator bias uncertainty in meters.  
fltFreqOffsetUnc  
Oscillator frequency offset uncertainty  
in meters/second.  
U8  
U8  
ucHaveBias  
Status flag indicating validity of bias.  
For all possible values, refer to  
Oscillator Status Code, page 54.  
ucHaveFreqOffset  
Status flag indicating validity of drift.  
For all possible values, refer to  
Operating Dimension, page 53.  
1.4.14  
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  
U32  
ulMeasMsec  
ulMeasCount  
The current GPS time when the  
temperature measurement was made.  
The measured TCO frequency (in  
counts/ucMsecInterval). This value  
varies with the temperature.  
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1.4.15  
npVersionTagType  
npVersionTagType lists a complete description of a product version.  
Data Type  
Variable  
cName[18]  
ucMajor  
ucMinor  
ucBeta  
Description  
S8  
U8  
U8  
U8  
U8  
U8  
U16  
Product name.  
Major version number.  
Minor version number.  
Beta version. 0 if this is a final release.  
Month of release.  
ucMonth  
ucDay  
Day of release.  
usYear  
Year of release.  
1.4.16  
npVersionType  
npVersionType 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 npVersionTagType, page 49.  
Data Type  
Variable  
Description  
npVersionTagType tMpFwVer  
npVersionTagType tNpApiVer  
npVersionTagType tNpSwVer  
npVersionTagType tRtosVer  
npVersionTagType tCpuVer  
Measurement platform version.  
Navigation platform API version.  
Navigation platform software version.  
Native RTOS version.  
Native processor version.  
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Using the FirstGPS API  
1.5  
FirstGPS API - #define Directives  
and Enumerated Data Types  
1.5.1  
Event Handling Constants  
Define  
Value  
Description  
EVENT_NO_WAIT  
0
For more information, refer to the lTimeOut  
parameter of navGetEvent, page 63.  
EVENT_WAIT_FOREVER  
EVENT_GET_FIRST  
EVENT_GET_LAST  
-1  
0
For more information, refer to the lTimeOut  
parameter of navGetEvent, page 63.  
For more information, refer to the ucGetFlag  
parameter of navGetEvent, page 63.  
1
For more information, refer to the ucGetFlag  
parameter of navGetEvent, page 63.  
1.5.2  
Almanac Status Code  
Define  
Value  
Description  
NO_ALMANAC_DATA  
HEALTH_PRESENT  
ALM_PAGES_PRESENT  
UTC_PRESENT  
0
1
2
4
8
There is no almanac data in the database.  
Indicates almanac health page is collected.  
Almanac is complete and current.  
Indicates UTC page is collected.  
Indicates ionospheric page is collected.  
IONO_PRESENT  
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 complete and current.  
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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. If the 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. If the 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.  
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1.5.3  
Channel Status Code  
Define  
Value  
Description  
STATUS_RESET  
0
Know nothing condition.  
MSEC ambiguity resolved.  
Delta phase + range.  
Phase, delta phase + range.  
Resolved 1/2 cycle.  
STATUS_TIME_KNOWN  
STATUS_FREQ_LOCK  
STATUS_PHASE_LOCK  
STATUS_LOCK_POINT_KNOWN  
STATUS_FRESH_MEAS  
1
2
4
8
16  
At least one measure in the last measured  
period; measured period is the inverse of  
the measurement rate.  
STATUS_GOOD_PARITY  
STATUS_VALID_MEAS  
STATUS_HEALTHY  
32  
At least 1 good parity result.  
64  
Measurement passes goodnesschecks.  
Satellite data = healthy.  
128  
1.5.4  
Navigation Status Code  
Define  
Value  
Description  
EPH_DECODED  
EPH_GOOD  
1
Ephemeris has been decoded.  
Ephemeris is good.  
2
EPH_USED_IN_FIX  
EPH_DGPS_CORR  
16  
32  
Used in the current position fix  
DGPS correction is available  
1.5.5  
DGPS Operating Mode  
Define  
Value  
Description  
DGPS_OFF  
0
1
2
3
Differential GPS is off.  
Set to differential GPS only.  
Auto mode off.  
DGPS_ONLY  
DGPS_AUTO_OFF  
DGPS_AUTO_ON  
Auto mode on.  
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1.5.6  
DGPS Configuration Mode  
Define  
Value  
Description  
DGPS_CFG_OFF  
DGPS_CFG_ONLY  
DGPS_CFG_AUTO  
0
1
2
Differential GPS is off.  
Set to differential GPS only.  
Auto mode.  
1.5.7  
Dynamic Mode Flag  
Define  
Value  
Description  
DYN_UNDEFINED  
DYN_LAND  
DYN_SEA  
0
1
2
3
4
5
Undefined dynamics.  
Land dynamics.  
Sea dynamics.  
DYN_AIR  
Air dynamics.  
DYN_STATIONARY  
N_DYN  
Stationary dynamics.  
Total number of dynamic modes.  
1.5.8  
Operating Dimension  
These definitions are used when setting the receiver's operation mode  
or reporting fix satellite selection.  
Define  
Value  
Description  
DIM_2D  
0
1
2
3
4
5
6
2D mode of operation.  
3D mode of operation.  
1SV mode of operation.  
Auto mode of operation.  
DGPS mode of operation.  
2D Clock Hold mode of operation.  
Over-determined clock mode.  
DIM_3D  
DIM_1SV  
DIM_AUTO  
DIM_DGPS_REF  
DIM_2D_CLK_HOLD  
DIM_OVERDET_CLK  
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1.5.9  
Oscillator Status Code  
Status flag for the oscillator drift/bias used by the ucHaveFreqOffset  
and ucHaveBias fields in npOscStatusType.  
Define  
Value  
Description  
HAOSC_UNKNOWN  
HAOSC_OLD  
0
1
2
3
4
No information.  
Old.  
HAOSC_FIX  
Based on position/timing fix.  
Approximate 1 SV solution.  
Have knowledge from raw measurement.  
HAOSC_APPX  
HAOSC_MEAS  
1.5.10  
Position Fix Source  
Source of the current position fix contained in the ucSource field of  
the navFixType structure.  
Define  
Value  
Description  
FIX_SOURCE_NONE  
FIX_SOURCE_INIT  
0
1
No position in memory.  
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  
FIX_SOURCE_3D  
FIX_SOURCE_OLD  
3
4
5
2D fix.  
3D fix.  
Fix is considered old, but is trusted from  
selected satellites.  
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1.5.11  
Position Fix Status  
Status of the current position fix contained in the ucStatus field of the  
navFixType structure.  
Define  
Value  
Description  
FIX_STATUS_NONE  
FIX_STATUS_OLD  
0
1
No position in memory.  
Fix is considered old, but is trusted from  
selected satellites.  
FIX_STATUS_NEW  
2
Fix is valid and new.  
1.5.12  
Position Fix DGPS Status  
Indicates if the position fix is differentially corrected.  
Define  
Value  
Description  
FIX_GPS_NOT_CORRECTED  
FIX_DGPS_CORRECTED  
0
1
Fix is not differentially corrected.  
Fix is differentially corrected.  
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1.5.13  
Position Status Code  
Status flag ucPosStatus has the following valid values. Only the  
values (47) and (0x80+(47)) should be considered to indicate that a  
valid position is available for output (navigation).  
Define  
Value  
Description  
HAVE_POS_NONE  
HAVE_POS_INIT  
0
1
No position in memory.  
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  
HAVE_POS_FIX2M  
HAVE_POS_FIX3A  
HAVE_POS_FIX3M  
HAVE_POS_DFIX2A  
4
2D fix in auto 2D/3D mode.  
2D fix in manual 2D mode.  
3D fix in auto 2D/3D mode.  
3D fix in manual 2D/3D mode.  
5
6
7
(HAVE_POS_FIX2A | 0x80)  
Same as HAVE_POS_FIX2A  
but differential mode.  
HAVE_POS_DFIX2M  
HAVE_POS_DFIX3A  
HAVE_POS_DFIX3M  
HAVE_POS_OLD  
(HAVE_POS_FIX2M | 0x80)  
(HAVE_POS_FIX3A | 0x80)  
(HAVE_POS_FIX3M | 0x80)  
8
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.  
HAVE_POS_APPX  
HAVE_POS_AVSV  
HAVE_POS_FRIM  
HAVE_POS_INTERNAL  
9
Fix is converging.  
10  
11  
12  
Fix is converging.  
Fix is converging.  
Internal fix - not suitable for use.  
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1.5.14  
Satellite Status Code  
Define  
Value  
Description  
SCODE_DOING_FIXES  
SCODE_GOOD_1SV  
SCODE_NEED_TIME  
SCODE_PDOP_HIGH  
SCODE_BAD_1SV  
SCODE_0SVS  
0
1
2
3
4
5
6
7
8
9
10  
Doing position fixes.  
A usable SV is available.  
Need GPS time.  
PDOP is too high.  
The chosen SV is unusable.  
No usable satellites.  
SCODE_1SV  
Only one usable satellite.  
Only two usable satellites.  
Only three usable satellites.  
Differential corrections.  
Over-determined clock.  
SCODE_2SVS  
SCODE_3SVS  
SCODE_DCORR_GEN  
SCODE_OVERDET_CLK  
1.5.15  
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  
T_STATUS_PROBLEM  
T_STATUS_APPX  
0
1
2
Time is unknown.  
Error detected. Now being fixed.  
Time is good to a few seconds, from  
outside the receiver.  
T_STATUS_SET  
3
4
Time is good to ±10 msecs, from tracking  
one satellite.  
T_STATUS_BIAS_KNOWN  
Time is good to ±1 µs, from a position fix.  
npTimeStatusType is the type that enumerates the above constants.  
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1.5.16  
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  
11  
12  
13  
15  
20  
New solution fix.  
NAV_NO_FIX_NEW  
Incapable of producing new fix.  
New SV tracking selection.  
New SV fix selection.  
NAV_TRK_SELECTION_NEW  
NAV_FIX_SV_SEL_NEW  
NAV_REF_DCORR_NEW  
NAV_POWER_ON_ACK  
Newly generated differential correction.  
Received request to turn on the FirstGPS  
software.  
NAV_START_UP_COMPLETE  
NAV_READY_TO_SHUTDOWN  
21  
22  
FirstGPS software started. Status valid.  
FirstGPS software ended. User can shutdown  
NAV_START_UP_FAILED  
NAV_TEMP_MEAS  
25  
27  
28  
FirstGPS software startup failed.  
Temperature measurement updated.  
1
NAV_FATAL_ERROR  
FirstGPS software fatal error generated.  
1
NAV_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).  
1.6  
FirstGPS API - Return Types  
The currently defined return types are:  
Define  
NAV_ERROR  
Value Description  
-1  
0
A function call failed.  
NAV_OK  
A function call is successful.  
Data retrieved is not complete.  
NAV_INCOMPLETE  
1
npRetCode is the FirstGPS API function return type that enumerates  
the above values.  
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A
1.7  
FirstGPS API - Function Descriptions  
1.7.1  
navGetBbAddr  
Get starting BBRAM address.  
Description  
The function navGetBbAddr 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 updated 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.  
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1.7.2  
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, npAllChStatusType, 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  
npAllChStatusType*  
Parameter  
Description  
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.  
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1.7.3  
navGetCompactTime  
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  
npCompTimeType*  
Parameter  
Description  
ptCompTime A pointer to the npCompTimeType 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  
NAV_ERROR  
The GPS time is retrieved successfully.  
The GPS time is not retrieved  
successfully.  
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1.7.4  
navGetDgpsCorrParams  
Get differential correction information.  
Description  
This function gets a copy of all the current differential correction  
parameters available from the navigation platforms 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 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.  
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1.7.5  
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.  
lTimeOut 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 calling task until either an event has been generated or the timeout  
(lTimeOut) 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.  
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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 (&gtEventHandlerTask,  
&ulEvent,  
&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.  
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Included Header File  
#include npStdIface.h”  
Format  
npRetCode  
navGetEvent (void* pvTaskId, U32* pulEvent, void*  
pvEventData, S32 lTimeOut, U8 ucGetFlag);  
Input Parameters  
Data Type  
Parameter  
Description  
void*  
pvTaskId  
A pointer to a task control block of the  
calling task.  
S32  
U8  
lTimeOut  
A timeout value.  
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  
NAV_ERROR  
The event is retrieved successfully.  
The event is not retrieved successfully.  
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1.7.6  
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) (IODE), 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  
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.  
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1.7.7  
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  
npNavConfigType*  
Parameter  
Description  
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.  
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1.7.8  
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  
npNavStatusType*  
Parameter  
Description  
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.  
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1.7.9  
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  
navGetNavVersion (npVersionType* ptVersion);  
Output Parameter  
Data Type  
Parameter  
ptVersion  
Description  
npVersionType*  
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.  
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1.7.10  
navGetOscStatus  
Get oscillator offset status.  
Description  
navGetOscStatus gets the navigation platforms current estimates of  
oscillator bias, frequency offset, and their uncertainties.  
Included Header File  
#include npStdIface.h”  
Format  
npRetCode  
navGetOscStatus (npOscStatusType* ptOscStatus);  
Output Parameter  
Data Type  
npOscStatusType*  
Parameter  
Description  
ptOscStatus  
Contains oscillator and frequency  
offset information. For a complete  
listing, refer to npOscStatusType,  
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.  
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1.7.11  
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  
usGpsWn  
Description  
U16  
U32  
GPS week number into the navigation platform.  
ulGpsTowMsec  
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  
NAV_ERROR  
The GPS time is imported successfully.  
The GPS time is not imported successfully.  
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1.7.12  
navPutDgpsCorrParams  
Put differential correction information.  
Description  
This function puts a copy of all the current differential correction  
parameters into the navigation platforms database.  
Included Header File  
#include npStdIface.h”  
Format  
npRetCode  
navPutDgpsCorrParams (npDgpsCorrType  
ptDgpsCorr[], U8 ucCount, U8 ucClearFlag);  
Input Parameters  
Data Type  
Parameter  
Description  
npDgpsCorrType*  
ptDgpsCorr  
A pointer to an array which contains  
the values to the navigation platform.  
For complete details, refer to  
npDgpsCorrType, page 40.  
U8  
U8  
ucCount  
Indicates number of valid entries.  
ucClearFlag  
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.  
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1.7.13  
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  
npNavConfigType*  
Parameter  
Description  
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.  
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1.7.14  
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 dblFreqOffset, FLT  
fltFreqSearch);  
Input Parameters  
Data Type  
Parameter  
Description  
DBL  
dblFreqOffset  
New oscillator frequency offset will be  
imported into the navigation platform in  
(meters/second).  
FLT  
fltFreqSearch  
The frequency to search around the  
dblFreqOffset 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.  
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1.7.15  
navGetSvSelections  
Get satellite selection.  
Description  
This function returns a list 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  
ptFixSvSel  
Description  
npFixSvSelType*  
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  
The npFixSvSelType structure has  
valid data.  
NAV_ERROR  
The npFixSvSelType structure does  
not have valid data.  
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1.7.16  
navGetTempParams  
Get temperature data.  
Description  
The function navGetTempParams gets the temperature data from the  
navigation platform. The data contain the following information:  
The number of milliseconds over which the temperature  
was made  
The time in ulMeasMsec when the navigation platform received  
the temperature measurement  
The 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);  
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Output Parameter  
Data Type  
npTempMeasType*  
Parameter  
Description  
ptTempMeas  
The npTempMeasType has all the  
temperature parameters for a  
measurement. For more information, refer  
to npTempMeasType, page 48.  
Return Values  
Value  
Description  
NAV_OK  
A copy of temperature measurement data  
is retrieved successfully.  
NAV_INCOMPLETE  
NAV_ERROR  
The measurement requested is not  
complete.  
A copy of temperature measurement data  
is not retrieved successfully.  
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1.7.17  
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  
ucMsecInterval  
Description  
U8  
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.  
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1.7.18  
navGpsShutDown  
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  
Value  
Description  
NAV_OK  
The shutdown of navigation platform is  
successful.  
NAV_ERROR  
The shutdown of navigation platform is  
not successful.  
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1.7.19  
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 determine 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  
U32  
U16  
U8  
fltTimeAccuracy Accuracy of time value input in milliseconds, 1 if unknown.  
ulGpgMsec  
usGpsWeek  
ucTimeStatus  
Approximate GPS time of week in milliseconds.  
GPS week number.  
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  
NAV_ERROR  
The initialization of navigation platform is successful.  
The initialization of navigation platform is not successful.  
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1.7.20  
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  
DBL*  
pdblPosLLA  
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.  
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A
Using the FirstGPS API  
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Glossary  
This section defines technical terms and abbreviations used in  
this manual.  
AMU  
A Trimble term: Arbitrary Measurement Unit. The AMU  
is defined as: 20 (AMU) +22.8 = CNO  
log10  
where CNO = C/N , that is, the carrier-to-noise ratio.  
0
ASIC  
Application-specific integrated circuit.  
ASCII  
American Standards Committee for Information  
Interchange. This organization established a hexadecimal-  
to-printed character translation table used by all  
computers to store character information.  
API  
Application Programming Interface.  
BBRAM  
Battery Backed-up RAM. See Start / Stop GPS, page 20  
and Load BBRAM on start, page 26.  
CNO  
Carrier-to-noise ratio. See AMU.  
Differential Global  
Positioning System  
(DGPS)  
GPS positions can be differentially corrected (DGPS) in  
real time (using radio telemetry) or through  
postprocessing (no radio telemetry required).  
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Glossary  
Dilution of precision  
(DOP)  
A description of the purely geometrical contribution to the  
uncertainty in a position fix, given by the expression:  
DOP = SQRT TRACE (A)  
T
-1  
where: A = (G G) of G, the geometry matrix,  
corresponding to the measurement connection matrix for  
the instantaneous position solution (dependent on  
1
satellite-receiver geometry) .  
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.  
1
Refer to Global Positioning System: Theory and  
Applications, Volume I. Parkinson, Spilker, Axelrad, and  
Enge (1996), p. 413.  
DSP  
DOP  
Digital Signal Processor.  
Dilution of precision.  
Earth-Centered-Earth-  
Fixed coordinates  
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.  
ECEF  
EMI  
See Earth-Centered-Earth-Fixed coordinates.  
Electromagnetic interference.  
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Glossary  
Global Positioning  
System (GPS)  
A system involving the use of satellite technology to  
calculate an accurate three-dimensional position. A GPS  
system consists of 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.  
Horizontal DOP  
(HDOP)  
See Dilution of precision.  
ICD-GPS-200  
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.  
IF  
Intermediate frequency.  
Issue of data (ephemeris).  
Local oscillator.  
IODE  
LO  
MPM  
NMEA  
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.  
PDOP  
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.  
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Glossary  
PRN  
Pseudo random noise.  
Position-Velocity-Time.  
PVT  
Real-time  
This term means to be performed immediately, not at  
some later time.  
RFIC  
RTOS  
SAW  
SV  
Radio Frequency Integrated Circuit.  
Real-time Operating System.  
Surface acoustic wave.  
Space vehicle, that is, GPS satellite.  
See Dilution of precision.  
TDOP  
TTFF  
TCO  
TCXO  
UTC  
Time to First Fix.  
Temperature-Compensated Oscillator.  
Temperature-Compensated Crystal Oscillator.  
Universal Time Coordinated; Universal Coordinated  
Time.  
VDOP  
XTAL  
See Dilution of precision.  
Crystal, as used in Figure 1.1 on page 5, for example.  
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Index  
A
ALM_PAGES_PRESENT 50  
Almanac 23, 46  
Almanac status code 50  
Almanac status flag 50  
Antenna 12  
Data logging 26  
Data types 38  
Date function 17  
dblBias 48  
dblDatumToMslAlt 45  
dblFreqOffset 48, 74  
dblOscBias 45  
Application Layer 9  
Application port 26  
Application settings 26  
Applications Programming Interface 2  
Azimuth 19  
dblPosECEF 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_1SV 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  
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  
FirstGPS Starter Kit User Guide 87  
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Index  
DYN_AIR 53  
DYN_LAND 53  
DYN_SEA 53  
DYN_STATIONARY 53  
DYN_UNDEFINED 53  
Dynamic mode flag 53  
fltAccuFlag 81  
fltAmuMask 44  
fltAzimuth 39  
fltBiasUnc 48  
fltDopMask 44  
fltElevMask 44  
fltFreqOffsetUnc 48  
fltHDOP 41  
E
Elevation 19  
Enumerated data types 50  
EPH_DECODED 52  
EPH_DGPS_CORR 52  
EPH_GOOD 52  
EPH_USED_IN_FIX 52  
Ephemeris 46  
fltMaxOscOffset 44  
fltOscFreq 45  
fltPDOP 41  
fltPdopSwitch 44  
fltPrc 40  
fltPrcErrEst 40  
fltReserved 41  
fltRrc 40  
fltRrcDot 40  
fltTDOP 41  
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  
fltTimeAccuracy 71 80  
,
fltVDOP 41  
fltVelECEF 45  
fltVelEnu 43  
F
Function descriptions 59  
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  
GPS position availability 46  
GPS system messages 24  
GPS time availability 46  
H
HAOSC_APPX 54  
HAOSC_FIX 54  
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HAOSC_MEAS 54  
HAOSC_OLD 54  
Monitor main menu 17  
Monitor program 14  
MPM interface motherboard 11  
MPM pinouts 9  
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  
MPM port 26  
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_START_UP_FAILED 58  
NAV_TEMP_MEAS 58, 76  
NAV_TRK_SELECTION_NEW 58  
navFixType 54, 55  
HDOP, See Horizontal DOP  
HEALTH_PRESENT 50  
Help, context-sensitive x  
Horizontal DOP 19 41  
,
Hot resets 21  
I
IO Interfaces 7  
IONO page 51  
IONO_PRESENT 50  
Ionosphere information 24  
navGetBbAddr 59  
navGetChStatus 35, 60  
navGetCompactTime 61  
navGetDgpsCorrParams 62  
navGetEvent 63  
navGetFixDgpsCorrection 35  
navGetLastFix 34, 35, 66  
navGetNavConfig 67  
L
Latitude-Longitude-Altitude coordinates 18  
least significant bit 39  
navGetNavStatus 68  
Local Oscillator 6  
navGetNavVersion 69  
lTimeOut 63, 65  
navGetOscStatus 70, 74  
navGetSvSelections 19, 35, 75  
FirstGPS Starter Kit User Guide 89  
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Index  
navGetTempParams 35, 76  
navGpsShutDown 32, 33, 35, 79  
navGpsStart 32, 35, 59, 80  
Navigation data types 39  
Navigation status code 52  
navInitTime 71  
position 23  
time 23  
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  
npCompTimeType 40  
npDgpsCorrType 40, 72  
npDopType 41  
npErrorEstType 41  
npFixChType 41  
npFixSvSelType 42, 75  
npFixType 43  
npNavConfigType 44  
npNavFixType 45  
pdblPosLLA 81  
PDOP, See Position DOP  
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  
Program status 20  
Protocols 22, 29  
ptAllChStatus 60  
ptCompTime 61  
ptDgpsCorr 62, 72  
ptFixSvSel 75  
ptNavConfig 67, 73  
ptNavFix 66  
ptNavStatus 68  
npNavStatusType 46  
npOscStatusType 48, 54  
npRetCode 58  
npTempMeasType 48  
npTimeStatusType 57  
npVersionTagType 49  
npVersionType 49  
ptOscStatus 70  
ptTempMeas 77  
ptVersion 69  
Num channels 27  
pucCount 62  
pulEvent 63, 65  
pulSize 59  
O
online Help x  
Operating dimension 53  
Oscillator offset 24  
Oscillator status code 54  
pvEventData 63, 65  
pvTaskId 63, 65  
PVT-serial solution 2  
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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  
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  
STATUS_TIME_KNOWN 52  
STATUS_VALID_MEAS 52  
Stop GPS 21  
cold 21  
hot 21  
warm 21  
Return types 58  
RF ASIC 3  
T_STATUS_APPX 57  
T_STATUS_PROBLEM 57  
T_STATUS_SET 57  
tChStatus 39  
tCpuVer 49  
tDop 42, 45  
TDOP, See Time DOP  
Temperature 25  
tErrorEst 43  
S
Satellite data 19  
Satellite identifier (PRN) 19  
Satellite status code 57  
Satellite visibility 25  
sCno 39, 41  
SCODE_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  
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  
Signal level output 23  
Signal strength 19  
Sky plots 22  
Standard FirstGPS events 58  
FirstGPS Starter Kit User Guide 91  
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Index  
ulMeasCount 48  
ulMeasMsec 48, 76  
usGpsWeek 80  
usGpsWn 71  
usMeasStatus 39  
usRefScount 40  
usReserved 39  
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  
ucIod 40  
usWeekTag 45  
usYear 49  
UTC_PRESENT 50  
ucIode 41  
ucLpFixRate 44  
ucMajor 49  
ucMemStatus 47  
ucMinor 49  
VDOP, See Vertical DOP  
Visual position 22  
Voltages 5  
ucMonth 49  
ucMsecInterval 48, 78  
ucNavStatus 39  
ucNumSvsUsed 45  
ucOprtngDim 44  
ucOscStatus 47  
ucPosStatus 47, 56  
ucSatCnt 42  
Warm resets 21  
World Wide Web site ix  
ucSource 45, 54  
ucStatus 40, 42, 45, 55  
ucSvId 39, 40  
ucSvUsed 41  
ucTimeStatus 47, 80  
ulAlmHealthStatus 47  
ulAlmPageStatus 47  
ulEphStatus 47  
ulGpgMsec 80  
ulGpsTowMsec 39, 71  
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FirstGPS Starter Kit User Guide  
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March 2001  
Revision A  
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