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

UniTraQ International Corp. RoHS compliance
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

UniTraQ International Corp. RoHS compliance
2009, 04, Version 1.2
3
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

UniTraQ International Corp. RoHS compliance
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%

UniTraQ International Corp. RoHS compliance
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.

UniTraQ International Corp. RoHS compliance
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.

UniTraQ International Corp. RoHS compliance
2009, 04, Version 1.2
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Eastern Star 5 series GT-525
GPS Module
6. MECHANIC DIMENSION