UniTraQ GT-525 User manual

Technical Manual
GPS Module Series Model: GT-525
Flash version
UniTraQ International Corp. All right reserved, © 2009
2F., No.136, Ziqiang S. Rd., Zhubei City, Hsinchu County 30264, Taiwan (R.O.C.)
TEL：[phone] FAX：[phone]
MADE IN TAIWAN

UniTraQ International Corp. RoHS compliance.
2009, 04, Version 1.2
Version History
Date Version Description of change Author
2008-09-12 0.1 Original Victor
2009-01-21 1.1 Enhance Warm start performance Victor
2009-04-06 1.2 Change New Address Julie

UniTraQ International Corp. RoHS compliance.
2009, 04, Version 1.2
Contents
1. Features………………………………………………………………..…………………………………………...1
2. Performance……………………………………………………………………………..…….…..……………….2
2.1 Receiver specification……………………………………………….…………………..…………………..2
2.2 Electric specification…………………………………….……………………………….…………………..3
2.2.1 Pin assignment……………………………………………..…...…………………….…………………..3
2.2.2 Absolute maximum ratings……………...………………………………………..…..………………... 3
2.2.3 DC electrical characteristics………………………………..……………………….…………………..4
2.2.4 GPS status indicator…………………………………...……..…………………………………………..4
2.3 Environment specification……………………….………………………….…….…….…………………..4
3. Communication specification……………………………………………………………….…………………..5
4. Connector…………………………………………………………………………………………………………...5
5. On board patch antenna…………...……………………………………………………………………………..6
6. Mechanic dimension………………………………………………………………………….…………………..7
7. Approved NMEA message…………………………………………….….……..………….……………………8
7.1 GGA – global positioning system fix data…………….………………………….…..…………………..8
7.2 GLL – latitude and longitude, with time of position fix and status……………….…………………..9
7.3 GSA – GPS DOP and active satellites……………..….….….….…….…..….….………………………10
7.4 GSV – GPS satellite in view………….….….….…..….…..….….….….….….……….………………….11
7.5 RMC – recommended minimum specific GPS/transit data…………...….….…...…………………..12
7.6 VTG – course over ground and ground speed…………….….….……….……..….………………….13
7.7 ZDA – time and data…..….….….….….…..….….….….….….….….….…...….….….………………….13
Eastern Star 5 series GT-525
GPS Module

UniTraQ International Corp. RoHScompliance
2009, 04, Version 1.2
1. FEATURES
zBuild on SiRF startIII chipset
z20 channels All-in-View tracking
zLow power consumption
z200,000+ effective correlates for very
fast TTFF and high sensitivity
acquisition
zHigh sensitivity for indoor fixes
zSBAS (WAAS and EGNOS) support
zReacquisition time 0.1 second
zBuild-in a lithium battery make GPS
fast positioning
z18X18X4 patch antenna
zCompact board size 19X19X11mm for
easy integration onto mobile device
zBuild on 18X18X4 patch antenna
zIntegrate LNA with low power control
zAverage Hot start time under 1sec
zAverage Cold start time under 40sec
zRoHS compliance
GT-525
Fast-Acquisition High-Sensitivity
20-Channel GPS Receiver Module
The GT-525 is a compact all-in-one GPS module solution
intended for a broad range of Original Equipment
Manufacturer (OEM) products, where fast and easy system
integration and minimal development risk is required.
The GT-525 is a low-power star performers deliver top-notch
accuracy, -159 dBm tracking, and track all satellites in view,
setting the benchmark for real-time navigation, even through
urban canyons and dense foliage. 200,000+ correlates—for
fast and deep signal searches—into a new power-saving
design, providing makers of portable and wireless devices
with a low-power premium GPS solution
Both the LVTTL-level and RS232 signal interface are
provided on the interface connector of the GT-525. Wide
range power supply voltage form 3.0V to 5.5V is supported.
1
Eastern Star 5 series GT-525
GPS Module

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2009, 04, Version 1.2
2
Eastern Star 5 series GT-525
GPS Module
2. PERFORMANCE
2.1 RECEIVER SPECIFICATIONS
Parameter Specification
Receiver Type 20 channels
Re-acquisition sensitivity -155dBm
Tracking sensitivity -159dBm
Cold start sensitivity -142dBm
Receiver frequency 1575.42MHz
Code C/A code
Accuracy
(1) Horizontal
(2) Velocity
10 meters, 2D RMS
7 meters 2D RMS, WAAS corrected
0.1m/sec
Startup Time
hot start
warm start
cold start
< 1 sec
< 25 sec
< 40 sec
Signal Reacquisition 0.1sec
Update Rate 1Hz (standard)
Operational Limits
(1) Altitude
(2) velocity
< 60,000ft
< 1,000knots
Datum WGS-84(Default)
Protocol NMEA-0183 V2.2
Power supply 3.0V to 5.5VDC
Connector 1.0mm pitch, right angle, 6 pin wafer connector

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
2.2 ELECTRIC SPECIFICATIONS
2.2.1 PIN ASSIGNMENT
NO. Signal name I/O V Description Notes
1 FTX0 O - Asynchronous serial output at
LVTTL level to output NMEA
message
2
FRX0 I - Asynchronous serial Input at
LVTTL level to Input NMEA
message
3 TX0 O - Asynchronous serial output at
RS-232 level to output NMEA
message
4 RX0 I - Asynchronous serial Input at
RS-232 level to Input NMEA
message
5 VCC P 3.0~5.5 Main power stability
6 GND O - Power and signal ground
2.2.2 ABSOLUTE MAXIMUM RATINGS
Item Absolute maximum ratings Unit
RX0 input voltage 0~3.3 (Max 4.0V) V
VCC input voltage 3.0~5.5(Max 6.0V) V

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
2.2.3 DC ELECTRICAL CHARACTERISTICS
Item Min. TYP Max Unit Notes
H Voltage 2.6 - 3.3 VTX0
(Output) L Voltage 0 - 0.4 V
H Voltage 2.6 - 3.3 VRX0
(Input) L Voltage 0 -- 0.4 V
Voltage 3.0 5.0 5.5 V
VCC Current 40mA 46mA - mA @5.0V
2.2.4 GPS STATUS INDICATOR
The GT-525 provides GPS status indicator. On board LED shows fix or non-fix. In fix mode, the LED will
be light for 1second and turn-off for 1second. In another mode, the pin will be light for 200ms and turn-off for
1800ms.
2.3 ENVIRONMENT SPECIFICATION
Parameter Specification
Operating -20℃~+60℃
Temperature
Storage -40℃~+80℃
Humidity 5%~95%

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
3. COMMUNICATION SEPECIFICATIONS
Item Description
Interface Full duplex serial interface
Bit rate 4800/9600/19200/38400/115200bps
Start bit 1bit
Stop bit 1bit
Data bit 8bit
Parity none
Transmission data SACII NMEA0183 Ver:2.2
Update rate 1Hz
GGA 1s,GSA 1s, GSV 5s, RMC 1s (typ) @4800 bps
GGA 1s,GSA 1s, GSV 1s, RMC 1s (typ) @9600 bps
Output sentence
GGA 1s,GSA 1s, GSV 1s, RMC 1s, VTG 1s, GLL 1s, ZDA 1s (typ)
@19200 bps or above
4. CONNECOTR
The connector mounted on the GT-525 GPS receiver module is a Molex’s board to wire connector, part
number is 501330-0600. The mating plugs part number is 501568-0607.

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
5. ON BOARD PATCH ANTENNA
(1) (2)
(1) 3D view of radiation pattern looking along the Y axis in the XZ plane
(2) 3D view of radiation pattern looking along the Z axis in the XY plane
When the GT-525 designed would be placed into a device, its patch antenna surface orientation shall be
vertically upturned to the sky. Also, shouldn’t put metal on the antenna above and selected suitable material
for converge the GT-525 if is required.
The GT-525 mounted a patch antenna which
radiates normally to its patch surface, the elevation
for φat 90 degrees would be important.
Left figure is shows the gain of the antenna at
1575MHz for φ= 90 degrees in the free space.
The maximum gain is obtained in the broadside
direction and this is measured to be 2 dBi for φat
90 degrees. The backlobe radiation is sufficiently
small and is measured to be -5.3 dBi for the left plot.
The 3D plots for the antenna are shown in above
Figure at different angles; it is easier to understand
the radiation from the antenna.

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
6. MECHANIC DIMENSION

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
7. APPROVED NMEA MESSAGE
The serial interface protocol is based on the National Marine Electronics Association’s NMEA 0183 ASCII
interface specification. This standard is fully define in “NMEA 0183, Version 2.2” The standard may be
obtained from NMEA, www.nmea.org
7.1 GGA – GLOBAL POSITIONING SYSTEM FIX DATA
Time, position and fix related data for a GPS receiver.
Structure:
$GPGGA,hhmmss.sss,ddmm.mmmm,a,dddmm.mmmm,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh<CR><LF>
1 2 3 4 56 7 8 9 10 11 12 13
Example:
$GPGGA,060932.448,2447.0959,N,12100.5204,E,1,08,1.1,108.7,M,,,,0000*0E<CR><LF>
Field Name Example Description
1 UTC Time 060932.448 UTC of position in hhmmss.sss format, (000000.00 ~
235959.99)
2 Latitude 2447.0959 Latitude in ddmm.mmmm format
Leading zeros transmitted
3 N/S Indicator N Latitude hemisphere indicator, ‘N’ = North, ‘S’ = South
4 Longitude 12100.5204 Longitude in dddmm.mmmm format
Leading zeros transmitted
5 E/W Indicator E Longitude hemisphere indicator, 'E' = East, 'W' = West
6 GPS quality
indicator
1 GPS quality indicator
0: position fix unavailable
1: valid position fix, SPS mode
2: valid position fix, differential GPS mode
3: GPS PPS Mode, fix valid
4: Real Time Kinematic. System used in RTK mode with
fixed integers
5: Float RTK. Satellite system used in RTK mode. Floating
integers
6: Estimated (dead reckoning) Mode
7: Manual Input Mode
8: Simulator Mode
7 Satellites Used 08 Number of satellites in use, (00 ~ 12)
8 HDOP 1.1 Horizontal dilution of precision, (00.0 ~ 99.9)
9 Altitude 108.7 mean sea level (geoid), (-9999.9 ~ 17999.9)
10 Geoid Separation Geoid separation in meters according to WGS-84 ellipsoid
(-999.9 ~ 9999.9)
11 DGPS Age Age of DGPS data since last valid RTCM transmission in
xxx format (seconds)
NULL when DGPS not used
12 DGPS Station ID 0000 Differential reference station ID, 0000 ~ 1023
NULL when DGPS not used
13 Checksum 0E
Note: The checksum field starts with a ‘*’ and consists of 2 characters representing a hex number. The
checksum is the exclusive OR of all characters between ‘$’ and ‘*’.

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
7.2 GLL - LATITUDE AND LONGITUDE, WITH TIME OF POSITION FIX AND STATUS
Latitude and longitude of current position, time, and status.
Structure:
$GPGLL,ddmm.mmmm,a,dddmm.mmmm,a,hhmmss.sss,A,a*hh<CR><LF>
1 2 3 4 5 6 7 8
Example:
$GPGLL,4250.5589,S,14718.5084,E,092204.999,A,A*2D<CR><LF>
Field Name Example Description
1 Latitude 4250.5589 Latitude in ddmm.mmmm format
Leading zeros transmitted
2 N/S Indicator S Latitude hemisphere indicator
‘N’ = North
‘S’ = South
3 Longitude 14718.5084 Longitude in dddmm.mmmm format
Leading zeros transmitted
4 E/W Indicator E Longitude hemisphere indicator
'E' = East
'W' = West
5 UTC Time 092204.999 UTC time in hhmmss.sss format (000000.00 ~ 235959.99)
6 Status A Status, ‘A’ = Data valid, ‘V’ = Data not valid
7 Mode Indicator A Mode indicator
‘N’ = Data not valid
‘A’ = Autonomous mode
‘D’ = Differential mode
‘E’ = Estimated (dead reckoning) mode
‘M’ = Manual input mode
‘S’ = Simulator mode
8 Checksum 2D

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
7.3 GSA - GPS DOP AND ACTIVE SATELLITES
GPS receiver operating mode, satellites used in the navigation solution reported by the GGA or GNS
sentence and DOP values.
Structure:
$GPGSA,A,x,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,x.x,x.x,x.x*hh<CR><LF>
1 2 3 3 3 3 3 3 3 3 3 3 3 3 4 5 6 7
Example:
$GPGSA,A,3,01,20,19,13,,,,,,,,,40.4,24.4,32.2*0A<CR><LF>
Field Name Example Description
1 Mode A Mode
‘M’ = Manual, forced to operate in 2D or 3D mode
‘A’ = Automatic, allowed to automatically switch 2D/3D
2 Mode 3 Fix type
1 = Fix not available
2 = 2D
3 = 3D
3 Satellite used 1~12 01,20,19,13,,,,,
,,,,
Satellite ID number, 01 to 32, of satellite used in solution,
up to 12 transmitted
4 PDOP 40.4 Position dilution of precision (00.0 to 99.9)
5 HDOP 24.4 Horizontal dilution of precision (00.0 to 99.9)
6 VDOP 32.2 Vertical dilution of precision (00.0 to 99.9)
7 Checksum 0A
7.4 GSV - GPS SATELLITE IN VIEW
Number of satellites in view, PRN number, elevation angle, azimuth angle, and C/No. Four satellites details
are transmitted per message. Additional satellite in view information is send in subsequent GSV messages.
Structure:
$GPGSV,x,x,xx,xx,xx,xxx,xx,…,xx,xx,xxx,xx *hh<CR><LF>
1 2 3 4 5 6 7 4 5 6 7 8
Example:
$GPGSV,3,1,09,28,81,225,41,24,66,323,44,20,48,066,43,17,45,336,41*78<CR><LF>
$GPGSV,3,2,09,07,36,321,45,04,36,257,39,11,20,050,41,08,18,208,43*77<CR><LF>
Field Name Example Description
1 Number of message 3 Total number of GSV messages to be transmitted (1-3)
2 Sequence number 1 Sequence number of current GSV message
3 Satellites in view 09 Total number of satellites in view (00 ~ 12)
4 Satellite ID 28 Satellite ID number, GPS: 01 ~ 32, SBAS: 33 ~ 64 (33 =
PRN120)
5 Elevation 81 Satellite elevation in degrees, (00 ~ 90)
6 Azimuth 225 Satellite azimuth angle in degrees, (000 ~ 359 )
7 SNR 41 C/No in dB (00 ~ 99)
Null when not tracking
8 Checksum 78

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
7.5 RMC - RECOMMANDED MINIMUM SPECIFIC GPS/TRANSIT DATA
Time, date, position, course and speed data provided by a GNSS navigation receiver.
Structure:
$GPRMC,hhmmss.sss,A,dddmm.mmmm,a,dddmm.mmmm,a,x.x,x.x,ddmmyy,x.x,a,a*hh<CR><LF>
1 2 3 4 5 6 7 8 9 10 111213
Example:
$GPRMC,092204.999,A,4250.5589,S,14718.5084,E,0.00,89.68,211200,,A*25<CR><LF>
Field Name Example Description
1 UTC time 092204.999 UTC time in hhmmss.sss format (000000.00 ~
235959.999)
2 Status A Status
‘V’ = Navigation receiver warning
‘A’ = Data Valid
3 Latitude 4250.5589 Latitude in dddmm.mmmm format
Leading zeros transmitted
4 N/S indicator S Latitude hemisphere indicator
‘N’ = North
‘S’ = South
5 Longitude 14718.5084 Longitude in dddmm.mmmm format
Leading zeros transmitted
6 E/W Indicator E Longitude hemisphere indicator
'E' = East
'W' = West
7 Speed over ground 000.0 Speed over ground in knots (000.0 ~ 999.9)
8 Course over ground 000.0 Course over ground in degrees (000.0 ~ 359.9)
9 UTC Date 211200 UTC date of position fix, ddmmyy format
10 Magnetic variation Magnetic variation in degrees (000.0 ~ 180.0)
11 Magnetic Variation Magnetic variation direction
‘E’ = East
‘W’ = West
12 Mode indicator A Mode indicator
‘N’ = Data not valid
‘A’ = Autonomous mode
‘D’ = Differential mode
‘E’ = Estimated (dead reckoning) mode
‘M’ = Manual input mode
‘S’ = Simulator mode
13 checksum 25

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2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
7.6 VTG - COURSE OVER GROUND AND GROUND SPEED
The Actual course and speed relative to the ground.
Structure:
GPVTG,x.x,T,x.x,M,x.x,N,x.x,K,a*hh<CR><LF>
1 2 3 4 5 6
Example:
$GPVTG,89.68,T,,M,0.00,N,0.0,K,A*5F<CR><LF>
Field Name Example Description
1 Course 89.68 True course over ground in degrees (000.0 ~ 359.9)
2 Course Magnetic course over ground in degrees (000.0 ~ 359.9)
3 Speed 0.00 Speed over ground in knots (000.0 ~ 999.9)
4 Speed 0.00 Speed over ground in kilometers per hour (0000.0 ~
1800.0)
5 Mode A Mode indicator
‘N’ = not valid
‘A’ = Autonomous mode
‘D’ = Differential mode
‘E’ = Estimated (dead reckoning) mode
‘M’ = Manual input mode
‘S’ = Simulator mode
6 Checksum 5F
7.7 ZDA -TIME AND DATE
Structure:
$GPRMC,hhmmss.sss,dd,mm.yyyy, , ,xxx<CR><LF>
1 2 3 4 5 6 7
Example:
$GPZDA,104548.04,25,03,2004,,*6C<CR><LF>
Field Name Example Description
1 UTC time 104548.04 UTC time in hhmmss.ss format, 000000.00 ~ 235959.99
2 UTC time: day 25 UTC time: day (01 ... 31)
3 UTC time: month 03 UTC time: month (01 ... 12)
4 UTC time: year 2004 UTC time: year (4 digit year)
5 Local zone hour
Not being output by the receiver (NULL)
6 Local zone minutes
Not being output by the receiver (NULL)
7 6C 6C Checksum

UniTraQ International Corp. RoHS compliance
2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
UniTraQ International Corp
2F., No.136, Ziqiang S. Rd., Zhubei City, Hsinchu County 30264, Taiwan (R.O.C.)
TEL：[phone] FAX：[phone]
Email [email protected]
Website www.unitraq.com
© 2009 UniTraQ International Corp. All rights reserved.
Not to be reproduced in whole or part for any purpose without written permission of UniTraQ International Corp (“UniTraQ”)
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UniTraQ products are not intended for use in medical, life-support devices, or applications involving potential risk of death,
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