UnRegistered
GM-668UB 161dBm GPS chipset.
SPECIFICATION GM-668-UB
GPS RECEIVER
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1. Introduction
1.1 Over view
is a GPS Mouse receiver build-in high performances - provides
customer high position, velocity and time accuracy performances as well as high sensitivity and tracking
capabilities. Customers benefit from the strength of both companies. Thanks to the low power consumption
technology, the GPS-Mouse receiver is ideal for many portable applications such as PDA, Tablet PC, smart
phone etc.
1.2 Feature
l Build on high performance GPS single chip
l Low power consumption
l RF Receiver of Noise Figure at 2.5 dB
l High Sensitivity -161 dBm (indoor)
l Integrated LNA with low-gain mode for active antenna option
l Assisted/Autonomous Operation
l Seamless Outdoor/Indoor Operation
l 48 channels in Search mode and 12 channels "All-in-View" tracking
l Up to 60,000 simultaneous search windows for fast TTFF and high sensitivity acquisitions
l Average cold start time under 35 seconds
l Support standard NMEA-0183 and binary protocol
l SBAS (WAAS, EGNOS and MSAS) support
l Integrated MIPS M4K CPU with software engineering services and available for embedded
customer defined applications
1.3 Product Application
l Handheld GPS receiver application
l Ideal for PDA, Pocket PC and other consumer devices requiring Positioning capability
l Geographic Surveying
l Sports and Recreation
UnRegistered
GM-668UB
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SPECIFICATION GM-668-UB
GPS RECEIVER
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l Marine Navigation, Fleet Management
l Automotive application
l Car navigation and tracking
l AVL and Location-Based Services
l Timing application
1.4 Product Picture
2 Technical Specifications
2.1 General Characteristics
2.1.1 General
Frequency L1, 1575.42 MHz
C/A code 1.023 MHz chip rate
Acquisition Channel
Tracking Channel
2.1.2 Accuracy
Position 2m CEP
SPECIFICATION GM-668-UB
GPS RECEIVER
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Velocity 0.1 m/s
Time 1PPS <20 ns resolution
2.1.3 Datum
WGS-84 Default WGS84
2.1.4 Time To First Fix （TTFF）
Hot start <2sec., average
Warm start <32sec., average
Cold start <35sec., average
2.1.5 Sensitivity
Tracking Sensitivity -161dBm, typical
Acquisition Sensitivity -142dBm, typical for cold start
2.1.6 Dynamic condition
Altitude 18000m(Max)
Velocity 515m/s(Max)
Acceleration 4g
Jerk 1g/s
2.2 Electrical Characteristics
2.2.1 DC Power
Voltage +3.3V DC
Supply current Under 40mA @ 3.3V DC Typical
Backup Battery Power +3.3V DC
SPECIFICATION GM-668-UB
GPS RECEIVER
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2.2.2 Serial Port
Electrical Interface Two full duplex serial communication
Baud rate
4.8K（Default）/9.6K/19.2K /38.4
/57.6K/115.2K
Navigation update rate 1Hz
Protocol Message NMEA-0183 Ver 3.01
2.2.3 Antenna
Type Active patch antenna
Center Frequency 1575.42 +/-1.032MHz
Polarization RHCP
Impedance 50 Ohm
2.3 Environmental Characteristics
Operating range -40°C ~ +85°C
Storage range -40°C ~ +150°C
Relative Humidity 5% ~ 80%
2.4 Physical Characteristics
Length 50mm
Width 39mm
Height 18mm
2.5 Absolute Maximum Ratings
Parameter Min Typ Max Unit
Power supply voltage -0.1 3.3 5 V
Input voltage -0.3 VDD V
USB 96
SPECIFICATION GM-668-UB
GPS RECEIVER
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3 Software Interface
3.1 NMEA V3.01 Protocol
Its output signal level is : 00bps (default), 8 bit data, 1 stop bit and no parity.
It supports the following NMEA-0183
Messages: GGA, GLL, GSA, GSV, RMC and VTG.
NMEA Output Messages: the module board outputs the following messages as shown in Table.
Table 1 NMEA-0183 Output Messages
NMEA Record Description
GGA Global positoning system fixed data
GLL Geogrphic position – latitude / longitude
GSA GNSS DOP and active satellites
GSV GNSS satellites in view
RMC Recommended minimum specific GNSS data
VTG Course over ground and ground speed
3.1.1 GGA-Global Postioning System Fixed Data
Table 2 contains the values of the following example:
$GPGGA, 161229.487, 3723.2475, N, 12158.3416, W, 1, 07, 1.0, 9.0, M, , , ,0000*18
Table 2 GGA Data Format
Name Example Units Description
Message ID $GPGGA GGA protocol header
UTC Position 161229.487 hhmmss.sss
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N=north or S=south
Longitude 12158.3416 Dddmm.mmmm
E/W Indicator W E=east or W=west
Position Fix Indicator 1 See Table 2-1
Satellites Used 07 Range 0 to 12
HDOP 1.0 Horizontal Dilution of
SPECIFICATION GM-668-UB
GPS RECEIVER
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Precision
MSL Altitude 9.0 meters
Units M meters
Geoid Separation meters
Units M meters
Age of Diff. Corr. second
Null fields when DGPS is
not used
Diff. Ref. Station ID 0000
Checksum *18
＜CR＞＜LF＞ End of message termination
Table 2-1 Position Fix Indicator
Value Description
0 Fix not available or invalid
1 GPS SPS Mode,fix valid
2 Differential GPS,SPS Mode,fix valid
3 GPS PPS Mode,fix valid
3.1.2 GLL-Geographic Position-Latitude/Longitude
Table 3 contains the values of the following Example:
$GPGLL, 3723.2475, N, 12158.3416, W, 161229.487, A*2C
Table 3 GLL Data Format
Name Example Units Description
Message ID $GPGGA GLL protocol header
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N=north or S=south
Longitude 12158.3416 Dddmm.mmmm
E/W Indicator W N=north or S=south
UTC Position 161229.487 Hhmmss.ss
Status A A=data valid or V=data not
SPECIFICATION GM-668-UB
GPS RECEIVER
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valid
Checksum *2C
＜CR＞＜LF＞ End of message termination
3.1.3 GSA-GNSS DOP and Active Satallites
Table 4 contains the values of the following example:
$GPGSA, A, 3, 07, 02, 26, 27, 09, 04, 15, , , , , , 1.8,1.0,1.5*33
Table 4 GSA Data Format
Name Example Units Description
Message ID $GPGSA GSA protocol header
Mode 1 A See Table 4-2
Mode 2 3 See Table 4-1
Satellite Used 07 Sv on Channel 1
Satellite Used 02 Sv on Channel 2
… …
Satellite Used Sv on Channel 12
PDOP 1.8 Position Dilution of Precision
HDOP 1.0 Horizontal Dilution of Precision
VDOP 1.5 Vertical Dilution of Precision
Checksum *33
＜CR＞＜LF＞ End of message termination
Table 4-1 Mode 1
Value Description
1 Fix not available
2 2D
3 3D
Table 4-2 Mode 2
Value Description
M Manual-forced to operate in 2D or 3D mode
A Automatic-allowed to automatically switch 2D/3D
SPECIFICATION GM-668-UB
GPS RECEIVER
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3.1.4 GSV-GNSS Satallites in View
Table 5 contains the values of the following example:
$GPGSV, 2, 1, 07, 07, 79, 048, 42, 02, 51, 062, 43, 26, 36, 256, 42, 27, 27,138, 42*71
$GPGSV, 2, 2, 07, 09, 23, 313, 42, 04, 19, 159, 41, 15, 12, 041, 42*41
Table 5 GGA Data Format
Name Example Units Description
Message ID $GPGSV GSV protocol header
Number of
Messages1
2 Range 1 to 3
Messages Number1 1 Range 1 to 3
Satellites in View 07
Satellite ID 07 Channel 1 ( Range 1 to 32 )
Elevation 79 degrees Channel 1 ( Maximum 90 )
Azimuth 048 degrees
Channel 1 ( Ture,Range 0 to
359 )
SNR(C/No) 42 dBHz
Range 0 to 99,null when not
tracking
… …
Satellite ID 27 Channel 4 ( Range 1 to 32 )
Azimuth 27 degrees Channel 4 ( Maximum 90 )
Elevation 138 degrees
Channel 4 ( Ture,Range 0 to
359 )
SNR(C/No) 42 dBHz
Range 0 to 99,null when not
tracking
Checksum *71
＜CR＞＜LF＞ End of message termination
1 Depending on the number of satellites tracked multiple messages of GSV data may be required.
3.1.5 RMC-Recommended Minimum Specific GNSS Data
Table 6 contains the values of the following example:
$GPRMC, 161229.487, A, 3723.2475, N, 12158.3416, W, 0.13, 309.62, 120598, ,*10
Table 6 GGA Data Format
SPECIFICATION GM-668-UB
GPS RECEIVER
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Name Example Units Description
Message ID $GPRMC RMC protocol header
UTC Position 161229.487 hhmmss.sss
Status A
A=data valid or V=data not
valid
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N=north or S=south
Longitude 12158.3416 ddmm.mmmm
E/W Indicator W E=east or W=west
Speed Over Ground 0.13 knots
Course Over Ground 309.62 degrees Ture
Date 120598 dBHz ddmmyy
Magnetic Varation E=east or W=west
Checksum *10
＜CR＞＜LF＞ End of message termination
3.1.6 VTG-Course Over Ground and Ground Speed
Table 7 contains the values of the following example:
$GPVTG, 309.62, T, , M, 0.13, N, 0.2, K*6E
Table 7 VTG Data Format
Name Example Units Description
Message ID $GPVTG VTG protocol header
Course 309.62 degrees Measured heading
Reference T Ture
Course degrees Measured heading
Reference M Magnetic
Speed 0.13 knots Measured horizontal speed
Units N knots
Speed 0.2 Km/hr Measured horizontal speed
Units K Kilometer per hour
Checksum *6E
SPECIFICATION GM-668-UB
GPS RECEIVER
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＜CR＞＜LF＞ End of message termination
4 Hardware Interface
The includes an antenna in a unique style waterproof gadget. We can
manufacture variable connector cable to suit your demands. Like USB, PHR(JST), GHR(JST),
Molex, PS2, RJ11, D-Sub 9..etc. You provide me specification, we manufacture the cable
and connector.
Definition of Pin assignment
GM-668UB