Qstarz GM-Q772 User Manual

Ultra Low Power, High Sensitivity

GPS Smart Receiver

User’s Guide

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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

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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.

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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.

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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 D­4 GND

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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.

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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

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$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 6 6 GGA 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 1 1 N=north or S=south
Longitude float 3,2.4 3,2.4 Degree * 100 + minutes.
E/W
indicator

Char 1 1 E=east or W=west

Position Fix
Indictor

Int 1 1 0: Fix not available or invalid.

1: GPS SPS mode. Fix available.
Satellites
Used

Int 2 2 Number 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 1 1 M Stands for “meters”.

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Geoid
Separation

Int (0) 1 4 Separation from Geoid, can be blank.

Units Char 1 1 M Stands for “meters”.
Age of
Differential
Corrections

int (0) 1 5 Age in seconds Blank (Null) fields when DGPS is not

used.

Diff
Reference
Corrections

int 4 4 0000.

Checksum *xx (0) 3 3 2 digits.
Message
terminator

<CR> <LF> 2 2 ASCII 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 6 6 GLL protocol header.
Latitude Float 1,2.1 3,2.4 Degree * 100 + minutes.
N/S Indicator Char 1 1 N=north or S=south.
Longitude Float 1,2.1 3,2.4 Degree * 100 + minutes.
E/W indicator Character 1 1 E=east or W=west.
UTC Time hhmmss.sss 1,2,2.1 2,2,2.3 Fix time to 1ms accuracy.
Status Char 1 1 A Data Valid.

V Data invalid.
Mode Indicator Char 1 1 A Autonomous
Checksum *xx (0) 3 3 2 digits.
Message terminator <CR><LF> 2 2 ASCII 13, ASCII 10.

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$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 6 6 GSA protocol header.
Mode Char 1 1 M Manual, forced to operate in selected mode.

A Automatic switching between modes.

Mode Int 1 1 1 Fix not available.

2 2D position fix.
3 3D position fix.

Satellites Used Int 2 2 SV on channel 1.
Satellites Used Int 2 2 SV on channel 2.

… . .. .. ..

Satellites Used Int 2 2 SV on channel 12.
PDOP Float 1.1 3.1
HDOP Float 1.1 3.1
VDOP Float 1.1 3.1
Checksum *xx 0 3 2 digits
Message terminator <CR> <LF> 2 2 ASCII 13, ASCII 10