Qstarz GM-Q772 User manual

Ultra Low Power, High Sensitivity
GPS Smart Receiver
User’s Guide

1
1. Introduction
1.1 Overview
The GPS Smart Receiver is an ultra low power GPS receiver based on the proven technology found in this 16
channel GPS receivers and NEMERIX chipset solution. The positioning application meets strict needs such as car
navigation, mapping, surveying, security, agriculture and so on. Only clear view of sky and certain power supply
are necessary to the device. With its ultra low power consumption, the smart receiver tracks up to 16 satellites at a
time, re-acquires satellite signals in 1 second (average) and updates position data every second.
1.2 Features
The GPS smart receiver provides a host of features that make it easy for integration and use.
1. Ultra low power design.
2. High performance receiver tracks up to 16 satellites.
3. Compact design ideal for applications with minimal space.
4. A rechargeable battery sustains internal clock and memory. It is recharged during normal operation.
5. User initialization is not required.
6. One full duplex serial communication and user selectable baud rates allow maximum interface capability and
flexibility.
7. Water proof (1 meter) design for all weather.
8. Built-in low noise, high gain active antenna.
2. Hardware Interface

2
2.1 Dimension
Dimensions: 53.0 (W) x 60.0 (D) x 26.0 (H) (mm)
2.0 (W) x 2.3 (D) x 1.0 (H) (inch)
2.2 Hardware Interface
The smart receiver includes a low noise, high gain active antenna in a unique style waterproof gadget. Simply
connect PS-2 female connector to one of the optional accessories and link to either your notebook PC, PDA or
other devices. The one-piece cigarette adapter allows you to connect smart receiver to your PDAs. Optional
connectors are listed and described below:
Connector
Standard cable: 2 meters with female PS-2 connector.

3
The GPS Smart Receiver is also equipped with optional connectors.
Pin Assignment of standard PS-2 Din Jack
Accessories
Mini Din Female and PS-2 male connector:
Cable Length: To GPS-6010: 1 meter
RS-232 to PS-2: 45 cm
Mini Din Female connector function definition:
Pin Signal
1 Tx (RS-232)
2 +5VDC
3 Tx (TTL)
4 GND
5 Rx (TTL)
6 Rx (RS-232)
Pin Signal
1 N.C.
2 TX
3 RX
4 N.C.
5 GND
6 N.C.
7 N.C.
8 N.C.
9 N.C.

4
PS2 composite connector function definition (to PC):
USB connector
The function definition of the A Type USB connector is as follows:
Pin Signal
1 +5VDC
2 N.C.
3 N.C.
4 GND
5 N.C.
6 N.C.
Pin Signal
1 +5VDC
2 D+
3 D-
4 GND

5
3. USB Driver Installation
3.1 System Requirements
IBM, Pentium or above and other compatible PC; 16 MB and above memory; Windows 98/Me/2000; VGA
Graphic Adapter
3.2 Installation
1. Copy entire <USB> folder from CD-ROM to hard disk.
2. Connect the USB connector to computer. While the computer automatically starts the installation program,
please direct the driver to the <USB> folder.
3. After the installation is complete, go to <Device Manager> and select <Ports (COM & LPT)> to verify if a
virtual COM port <USB to Serial Port> was created.
3.3 Important Notice
Verify the COM port # to start using your own navigating software.
1. Click <Start> menu, select <Settings>, then enter <Control Panel>
2. After entering <Control Panel>, select <System>
3. Select <Device Manager>
4. Find the <Connect Port> and check the Virtual COM Port, which was created by the USB driver. Please note
that the Virtual COM Port number might be different from every computer. Before using navigating software,
please confirm the COM Port numbers created by your computer and provided by your navigation software. They
must be the same Com Port numbers. Otherwise, the navigating software won’t receive the satellite signal for the
un-match COM Port setting.
4. Warranty
The GPS smart receiver is warranted to be free from defects in material and functions for 1 year from the date of
purchase. Any failure of this product within this period under normal conditions will be replaced at no charge to
the customers.

6
Appendix : Software Specification
NMEA Protocol
The software is capable of supporting the following NMEA message formats
NMEA Message Prefix Format Direction
SGPGGA GPS fix data. Out
SGPGLL Geographic position Latitude / Longitude. Out
SGPGSA GNSS DOP and actives satellites Out
SGPGSV Satellites in view. Out
SGPRMC Recommended minimum specific GNSS data. Out
SGPVTG Velocity and track over ground. Out
SGPZDA Date and time. Out
NMEA Extensions
The software is capable of supporting the following NMEA extensions:
NMEA Message Prefix Format Direction
$PNMRX100 Set serial port parameters. In
$PNMRX101 Navigation initialization In
$PNMRX103 NMEA message rate control In
$PNMRX104 LLA navigation initialization In
$PNMRX106 Set Datum. In
$PNMRX107 NemeriX messages rate control In
$PNMRX108 NMEA message sequence control In
$PNMRX110 Fix Settings In
$PNMRX111 Software Reset In
$PNMRX112 Operating Mode Control In
$PNMRX113 Fix and Extraction control In
$PNMRX300 Almanac data transfer In / Out
$PNMRX301 Ephemeris data transfer. Out
$PNMRX302 Ionospheric correction Out
$PNMRX303 UTC Time Out
$PNMRX304 GPS Constellation Health Status Out
$PNMRX600 SW Version report Out
$PNMRX601 ISP mode In
$PNMRX602 Flash content version report Out

7
$PNMRX603 Settings Report Out
General NMEA Format
The general NMEA format consists of an ASCII string commencing with a ‘$’ character and
terminating with a <CR><LF> sequence. NMEA standard messages commence with ‘GP’ then a
3-letter message identifier. NemeriX specific messages commence with $PNMRX followed by a 3
digit number. The message header is followed by a comma delimited list of fields optionally
terminated with a checksum consisting of an asterix ‘*’ and a 2 digit hex value representing the
checksum. There is no comma preceding the checksum field. When present, the checksum is
calculated as a bytewise exclusive of the characters between the ‘$’ and ‘*’. As an ASCII
representation, the number of digits in each number will vary depending on the number and
precision, hence the record length will vary. Certain fields may be omitted if they are not used, in
which case the field position is reserved using commas to ensure correct interpretation of
subsequent fields.
The tables below indicate the maximum and minimum widths of the fields to allow for buffer
size allocation.
$GPGGA
This message transfers global positioning system fix data. The $GPGGA message structure is
shown below:
Field Format Min chars Max chars Notes
Message ID $GPGGA 66GGA protocol header.
UTC Time hhmmss.sss 2,2,2.3 2,2,2.3 Fix time to 1ms accuracy.
Latitude float 3,2.4 3,2.4 Degrees * 100 + minutes.
N/S Indicator
char 11N=north or S=south
Longitude float 3,2.4 3,2.4 Degree * 100 + minutes.
E/W
indicator
Char 11E=east or W=west
Position Fix
Indictor
Int 110: Fix not available or invalid.
1: GPS SPS mode. Fix available.
Satellites
Used
Int 22Number of satellites used to calculate fix.
HDOP Float 1.1 3.1 Horizontal Dilution of Precision.
MSL Altitude Float 1.1 5.1 Altitude above mean seal level
Units Char 11M Stands for “meters”.

8
Geoid
Separation
Int (0) 1 4Separation from Geoid, can be blank.
Units Char 11M Stands for “meters”.
Age of
Differential
Corrections
int (0) 1 5Age in seconds Blank (Null) fields when DGPS is not
used.
Diff
Reference
Corrections
int 440000.
Checksum *xx (0) 3 32 digits.
Message
terminator
<CR> <LF> 22ASCII 13, ASCII 10.
$GPGLL
This message transfers Geographic position, Latitude, Longitude, and time. The $GPGLL
message structure is shown below:
Field Format Min chars Max chars Notes
Message ID $GPGLL 66GLL protocol header.
Latitude Float 1,2.1 3,2.4 Degree * 100 + minutes.
N/S Indicator Char 11N=north or S=south.
Longitude Float 1,2.1 3,2.4 Degree * 100 + minutes.
E/W indicator Character 11E=east or W=west.
UTC Time hhmmss.sss 1,2,2.1 2,2,2.3 Fix time to 1ms accuracy.
Status Char 11A Data Valid.
V Data invalid.
Mode Indicator Char 11A Autonomous
Checksum *xx (0) 3 32 digits.
Message terminator <CR><LF> 22ASCII 13, ASCII 10.

9
$GPGSA
This message transfers DOP and active satellites information. The $GPGSA message structure
is shown below:
Field Format Min chars
Max chars Notes
Message ID $GPGSA 66GSA protocol header.
Mode Char 11M Manual, forced to operate in selected mode.
A Automatic switching between modes.
Mode Int 111Fix not available.
22D position fix.
33D position fix.
Satellites Used Int 22SV on channel 1.
Satellites Used Int 22SV on channel 2.
…... .. ..
Satellites Used Int 22SV on channel 12.
PDOP Float 1.1 3.1
HDOP Float 1.1 3.1
VDOP Float 1.1 3.1
Checksum *xx 032 digits
Message terminator <CR> <LF> 22ASCII 13, ASCII 10

10
$GPGSV
This message transfers information about satellites in view. The $GPGSV message structure is
shown below. Each record contains the information for up to 4 channels, allowing up to 12
satellites in view. In the final record of the sequence the unused channel fields are left blank with
commas to indicate that a field has been omitted.
Field Format Min chars
Max chars Notes
Message ID $GPGSV 66GSA protocol header.
Number of messages Int 11Number of messages in the message sequence
from 1 to 3.
Message number Int 11Sequence number of this message in current
sequence, form 1 to 3.
Satellites in view Int 12Number of satellites currently in view.
Satellite Id Int 22Satellite vehicle 1.
Elevation Int 13Elevation of satellite in degrees.
Azimuth Int 13Azimuth of satellite in degrees.
SNR Int (0) 1 2Signal to noise ration in dBHz, null if the sv is not
in tracking.
Satellite Id Int 22Satellite vehicle 2.
Elevation Int 13Elevation of satellite in degrees.
Azimuth Int 13Azimuth of satellite in degrees.
SNR Int (0) 1 2Signal to noise ration in dBHz, null if the sv is not
in tracking.
Satellite Id Int 22Satellite vehicle 3.
Elevation Int 13Elevation of satellite in degrees.
Azimuth Int 13Azimuth of satellite in degrees.
SNR Int (0) 1 2Signal to noise ration in dBHz, null if the sv is not
in tracking.
Satellite Id Int 22Satellite vehicle 4.
Elevation Int 13Elevation of satellite in degrees.
Azimuth Int 13Azimuth of satellite in degrees.
SNR Int (0) 1 2Signal to noise ration in dBHz, null if the sv is not
in tracking.
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.

11
$GPRMC
This message transfers recommended minimum specific GNSS data. The $GPRMC message
format is shown below.
Field Format Min chars Max chars Notes
Message ID $GPRMC 66RMC protocol header.
UTC Time hhmmss.sss 1,2,2.1 2,2,2.3 Fix time to 1ms accuracy.
Status char 11A Data Valid.
V Data invalid.
Latitude Float 1,2.1 3,2.4 Degrees * 100 + minutes.
N/S Indicator Char 11N=north or S=south.
LongitudeFloat 1,2.1 3,2.4 Degrees * 100 + minutes.
E/W indicator Char 11E=east or W=west.
Speed over ground Float 1,1 5.3 Speed over ground in knots.
Course over ground Float 1.1 3.2 Course over ground in degrees.
Date ddmmyy 2,2,2 2,2,2 Current date.
Magnetic variation Blank (0) (0) Not used.
E/W indicator Blank (0) (0) Not used.
Mode Char 11A Autonomous
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.

12
$GPVTG
This message transfers Velocity, course over ground, and ground speed. The $GPVTG message
format is shown below.
Field Format Min chars
Max chars
Notes
Message ID $GPVTG 66VTG protocol header.
Course (true) Float 1.1 3.2 Measured heading in degrees.
Reference Char 11T = true heading.
Course (magnetic) Float 1.1 3.2 Measured heading (blank).
Reference Char 11M = magnetic heading.
Speed Float 1.1 4.2 Speed in knots.
Units Char 11N = knots.
Speed Float 1.1 4.2 Speed
units Char 11K = Km/h.
Mode Char 11A Autonomous
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF>
22ASCII 13, ASCII 10.

13
$GPZDA
This message transfers UTC Time and Date. Since the latency of preparing and transferring the
message is variable, and the time does not refer to a particular position fix, the seconds precision is
reduced to 2 decimal places. The $GPZGA message format is shown below.
Field Format Min chars
Max chars
Notes
Message ID $GPZDA 66ZDA protocol header.
UTC time hhmmss.ss 2,2,2.2 2,2,2.2 00000000.00 to 235959.99
UTC day dd 2201 to 31, day of month.
UTC month mm 2201 to 12.
UTC Year yyyy 441989-9999.
Local zone hours Int (-)2 (-)2 Offset of local time zone (-13) to 13.
Local zone minutes Unsigned 22
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF>
22ASCII 13, ASCII 10.
Extensions Specification
For all $PNMRX messages it is possible to configure an alternative string to replace the NMRX
part, the node always responds to the $PNMRX strings and can be configured to generate and
respond to the alternative string.
$PNMRX100, Set serial port mode
This message is sent to control the serial communications port parameters. The $PNMRX100
message format is shown below.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX100 66PNMRX100 protocol header.
Protocol Char 110NMEA mode
1NemeriX Binary Mode (under dev)
Baud Int 461200.
2400.
4800.
9600.
19200.
38400.
57600.
Parity Char 110. None.
1. Odd.
2. Even.

14
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
Examples:
$PNMRX100,0,4800,0*xx : sets the UART baud rate to 4800 bps and no parity.
$PNMRX101, Navigation Initialization
This message is sent to initialize navigation parameters to speed up initial acquisition time. The
$PNMRX101 message format is shown below.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX101 68PNMRX101 protocol header.
ECEF_X Int (-)7 (-)7 Signed ECEF x co-ordinate in meters
ECEF_Y Int (-)7 (-)7 Signed ECEF y co-ordinate in meters
ECEF_Z Int (-)7 (-)7 Signed ECEF z co-ordinate in meters
Clock offset Int (0) 1 6Clock offset of GPS receiver, in [Hz x 100] wrt L1.
This changes the clock bias stored in the settings not
the actual clock bias used by the system. A cold start is
necessary, in order to use this value.
Time of week Int 16Offset from start of week in seconds
Week number Int 14GPS week number
Channel count Int 12Maximum number of TM to be used. Min 12, max 16.
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
-If used, all three X,Y, and Z components of the ECEF position must be provided,
otherwise the message is declared invalid as a whole
-Modifying the ECEF coordinates triggers a software system reset after successful
execution of the message
Examples:
$PNMRX101,,,,,,,,8,*xx : Executes a factory reset
$PNMRX101,-742507,-5462738,3196706,,,,,,*xx: Sets the receiver position to ECEF (,,) and
executes a software reset
$PNMRX101,,,,,,,,4,*xx : Sets the fix procedure mode the cold start. This
will be valid after each reset, until this value is
changed.

15
$PNMRX103, NMEA rate control
This message is sent to enable or pause the output of an NMEA message and to determine its
output rate. The sequence of the output sequence is determined by the $PNMRX107 message. The
$PNMRX103 message format is shown below. The rate of each message can individually be set. If
‘0’ is used, the output of the message is skipped (according to the message sequence). The message
length is limited to 80 characters, in the event that the message length would exceed 80 characters
it is divided into 2 messages. This message is supported also in a variable length format, where
only the necessary fields are used.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX103 88PNMRX103 protocol header.
Mask ID Int 33Mask identifier: possibilities are
GGA
GLL
GSA
GSV
RMC
VTG
ZDA
ALL (applies to all messages)
Mask value Int 11Output rate in seconds (0=paused)
Mask ID Int 22Mask identifier.
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
Examples:
$PNMRX103, GSV, 2,GGA, 1,ZDA, 0*xx: GSV is output every 2s,GGA every 1s and ZDA is
skipped.
$PNMRX103, GSV, 2,GGA, 1,ZDA, 0,,,,,,,,,*xx :same as above, but using a fixed length message
$PNMRX103, ALL, 2*xx: all messages are output every 2s.
$PNMRX103, ALL, 0*xx: skips all messages.

16
$PNMRX104, LLA navigation initialization
This message enables the receiver to be initialized using LLA data to speed up satellite
acquisition. The first 4 values defining the position (if used) must be all present in the message.
Otherwise the whole massage is considered invalid.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX104 88PNMRX104 protocol header. (under dev.)
Latitude Float 1,2.1 3,2.4 Degrees * 100 + minutes. (under dev.)
N/S Indicator Char 11N=north or S=south. (under dev.)
Latitude Float 1,2.1 3,2.4 Degrees * 100 + minutes. (under dev.)
E/W Indicator Char 11E=east or W=west. (under dev.)
Altitude Int (-) 1 (-) 6 Altitude above MSL, in meters.
Clock offset Int (0) 1 6Clock offset of GPS receiver. This changes the clock
bias stored in the settings, not the actual clock bias
used by the system. A cold start is necessary, in order
to use this value.
Time of week Int 16Offset from start of week in seconds. (under dev.)
Week number Int 14GPS week number.
Channel count Int 12Maximum number of TM to be used. Min12, max 16.
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
-If used, all five components (Lat, N/S, Long E/W, alt) of the LLA position must be
provided, otherwise the message is declared invalid as a whole
-Modifying the LLA coordinates triggers a software system reset after successful
execution of the message.

17
$PNMRX106, Datum
This message defines the conversion model used for mapping the ECEF coordinates into the
LLA ones. The default transformation uses WGS84 approximation. The transformation method can
be changed into one using a reference Ellipsoid combined with a local datum, to obtain a specific
estimation of the local earth geometry. Once the datum has been changed it will be applied to all
LLA data, including the LLA navigation initialization Data. This message enables the receiver to be
configured to use map datum from an internal table, or datum supplied as part of the message.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX106 68PNMRX106 protocol header.
Correction Mode Unsigned 11If 1 apply EGM96 geoid correction (warning: should
be applied only when Map Datum is equal to 216). If
0 there is no EGM96 geoid correction.
Reference number of the appropriate map datum to
apply.
Map Datum Int (0) 1 3
0-218 Map datum from internal table
500 User defined Datum
Dx Int (0) (-)1 (-)5 X offset in meters (-9999 to 9999)
Dy Int (0) (-)1 (-)5 Y offset in meters (-9999 to 9999)
Dz Int (0) (-)1 (-)5 Z offset in meters (-9999 to 9999)
Iflat Int (0) 1 8Inverse flatness of reference geode. The value to be
used is (IFlat –290) * 1000000).
The value must be in the range [6000000, 12000000]
Majora Int (0) 18Semi major axis of reference geode. The values to be
used is (MajorA –6370000) * 1000).
The value must be in the range [6000000, 9000000]
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
Examples:
$PNMRX106, 0,500, -2000,-2000,-2000,8257224,8137000*00*xx : User defined Datum
$PNMRX106, 1,216,,,,,*xx : WGS 84 Datum

18
$PNMRX107, Messages rate control
This message is sent to set the automatic update rate, and to configure which messages will be
automatically output, it is also sent from the node to report which messages are currently
configured for automatic transmission. The $PNMRX107 message format is shown below. This
message can be used to enable and disable multiple messages by including up to 4 message codes
and associated fields in each $PNMRX107 message.
The message length is limited to 80 characters, in the event that the message length would
exceed 80 characters it is divided into 2 messages. This message is supported also in a variable
length format, where only the necessary fields are used.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX107 88PNMRX107 protocol header.
Determines which message is being configured.Message code Char 33
300 PNMRX300 Almanac Data
301 PNMRX301 Ephemeris Data
302 PNMRX302 lonospheric corrections
303 PNMRX303 UTC Time
304 PNMRX304 GPS constellation health
ALL Applies to all messages
Mode Int 110Disable message
1Send message now
2Send message on change
3Send message now and on change
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
Examples:
$PNMRX107,300,1*xx : Output the almanac stored in NVRAM
$PNMRX107,301,2*xx : Output Ephemeris will be output on change
$PNMRX107,ALL,2*xx : Output all output messages (300,301,302,303,304)

19
$PNMRX108, NMEA message sequence
This message is used to set the sequence used to output the NMEA messages. All messages in
the list are set to be output with a default output rate. The messages that are not included are
disabled. Once the sequence is defined, individual settings for the messages can be changed by
means of the $PNMRX103 message. This message is supported also in a variable length format,
where only the necessary fields are used.
Field Format Min chars
Max chars
Notes
Message ID $PNMRX108 68PNMRX108 protocol header.
Mask ID Int 33Mask identifier: possibilities are
GGA
GLL
GSA
GSV
RMC
VTG
ZDA
Mask ID Int 33Mask Identifier.
Checksum *xx (0) 3 32 digits.
Message terminator <CR> <LF> 22ASCII 13, ASCII 10.
Examples:
$PNMRX108,GGA,GLL,GSA*xx : Enables the GGA, GLL and GSA in this sequence, output
every second.All other messages are disabled