Lassen SQ User manual

F
Part Number 47838-00
Revision A
June 2002
Lassen™ SQ GPS
Receiver
System Designer Reference Manual

Corporate Office
Trimble Navigation Limited
Components Technologies Division
645 North Mary Avenue
Post Office Box 3642
Sunnyvale, CA 94088-3642
U.S.A.
Phone: [phone]
Fax: [phone]
www.trimble.com
Support Offices
Trimble Navigation Limited
Components Technologies Division
645 North Mary Avenue
Post Office Box 3642
Sunnyvale, CA 94088-3642
U.S.A.
Phone: [phone]
Fax: [phone]
Trimble Navigation Europe Limited
Trimble House
Meridian Office Park
Osborn Way, Hook
Hampshire RG27 9HX
England
Phone: [phone]
Fax: [phone]
Copyright and Trademarks
© 2002 Trimble Navigation Limited. All rights
reserved. No part of this manual may be copied,
reproduced, translated, or reduced to any
electronic medium or machine-readable form for
any use other than with the Lassen™ SQ GPS
Receiver.
The Globe & Triangle logo, Trimble, Colossus,
FirstGPS, and Lassen, are trademarks of Trimble
Navigation Limited.
The Sextant logo withTrimble is a trademark of
Trimble Navigation Limited, registered in the
United States Patent and Trademark Office.
All other trademarks are the property of their
respective owners.
Release Notice
This is the June 2002 release (Revision A) of the
Lassen™ SQ GPS Receiver System Designer
Reference Manual, part number 47838-00.
The following limited warranties give you specific
legal rights. You may have others, which vary
from state/jurisdiction to state/jurisdiction.
Hardware Limited Warranty
Trimble warrants that this Trimble hardware
product (the “Product”) shall be free from defects
in materials and workmanship and will
substantially conform to Trimble’s applicable
published specifications for the Product for a
period of one (1) year, starting from the date of
delivery. The warranty set forth in this paragraph
shall not apply to software/firmware products.
Software and Firmware License, Limited
Warranty
This Trimble software and/or firmware product
(the “Software”) is licensed and not sold. Its use is
governed by the provisions of the applicable End
User License Agreement (“EULA”), if any,
included with the Software. In the absence of a
separate EULA included with the Software
providing different limited warranty terms,
exclusions, and limitations, the following terms
and conditions shall apply. Trimble warrants that
this Trimble Software product will substantially
conform to Trimble’s applicable published
specifications for the Software for a period of
ninety (90) days, starting from the date of
delivery.
Warranty Remedies
Trimble's sole liability and your exclusive remedy
under the warranties set forth above shall be, at
Trimble’s option, to repair or replace any Product
or Software that fails to conform to such warranty
(“Nonconforming Product”), or refund the
purchase price paid by you for any such
Nonconforming Product, upon your return of any
Nonconforming Product to Trimble in accordance
with Trimble’s standard return material
authorization procedures.

Warranty Exclusions and Disclaimer
These warranties shall be applied only in the event
and to the extent that: (i) the Products and
Software are properly and correctly installed,
configured, interfaced, maintained, stored, and
operated in accordance with Trimble’s relevant
operator's manual and specifications, and; (ii) the
Products and Software are not modified or
misused. The preceding warranties shall not apply
to, and Trimble shall not be responsible for defects
or performance problems resulting from (i) the
combination or utilization of the Product or
Software with products, information, data,
systems or devices not made, supplied or specified
by Trimble; (ii) the operation of the Product or
Software under any specification other than, or in
addition to, Trimble's standard specifications for
its products; (iii) the unauthorized modification or
use of the Product or Software; (iv) damage
caused by accident, lightning or other electrical
discharge, fresh or salt water immersion or spray;
or (v) normal wear and tear on consumable parts
(e.g., batteries).
THE WARRANTIES ABOVE STATE TRIMBLE'S
ENTIRE LIABILITY, AND YOUR EXCLUSIVE
REMEDIES, RELATING TO PERFORMANCE OF
THE PRODUCTS AND SOFTWARE. EXCEPT AS
OTHERWISE EXPRESSLY PROVIDED HEREIN,
THE PRODUCTS, SOFTWARE, AND
ACCOMPANYING DOCUMENTATION AND
MATERIALS ARE PROVIDED “AS-IS” AND
WITHOUT EXPRESS OR IMPLIED WARRANTY
OF ANY KIND BY EITHER TRIMBLE
NAVIGATION LIMITED OR ANYONE WHO HAS
BEEN INVOLVED IN ITS CREATION,
PRODUCTION, INSTALLATION, OR
DISTRIBUTION, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE, TITLE, AND
NONINFRINGEMENT. THE STATED EXPRESS
WARRANTIES ARE IN LIEU OF ALL
OBLIGATIONS OR LIABILITIES ON THE PART
OF TRIMBLE ARISING OUT OF, OR IN
CONNECTION WITH, ANY PRODUCTS OR
SOFTWARE. SOME STATES AND
JURISDICTIONS DO NOT ALLOW LIMITATIONS
ON DURATION OR THE EXCLUSION OF AN
IMPLIED WARRANTY, SO THE ABOVE
LIMITATION MAY NOT APPLY TO YOU.
TRIMBLE NAVIGATION LIMITED IS NOT
RESPONSIBLE FOR THE OPERATION OR
FAILURE OF OPERATION OF GPS SATELLITES
OR THE AVAILABILITY OF GPS SATELLITE
SIGNALS.
Limitation of Liability
TRIMBLE’SENTIRE LIABILITY UNDER ANY
PROVISION HEREIN SHALL BE LIMITED TO
THE GREATER OF THE AMOUNT PAID BY YOU
FOR THE PRODUCT OR SOFTWARE LICENSE OR
U.S.$25.00. TO THE MAXIMUM EXTENT
PERMITTED BY APPLICABLE LAW, IN NO
EVENT SHALL TRIMBLE OR ITS SUPPLIERS BE
LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES
WHATSOEVER UNDER ANY CIRCUMSTANCE
OR LEGAL THEORY RELATING IN ANY WAY TO
THE PRODUCTS, SOFTWARE, AND
ACCOMPANYING DOCUMENTATION AND
MATERIALS, (INCLUDING, WITHOUT
LIMITATION, DAMAGES FOR LOSS OF
BUSINESS PROFITS, BUSINESS INTERRUPTION,
LOSS OF BUSINESS INFORMATION, OR ANY
OTHER PECUNIARY LOSS), REGARDLESS OF
WHETHER TRIMBLE HAS BEEN ADVISED OF
THE POSSIBILITY OF ANY SUCH LOSS AND
REGARDLESS OF THE COURSE OF DEALING
WHICH DEVELOPS OR HAS DEVELOPED
BETWEEN YOU AND TRIMBLE. BECAUSE SOME
STATES AND JURISDICTIONS DO NOT ALLOW
THE EXCLUSION OR LIMITATION OF LIABILITY
FOR CONSEQUENTIAL OR INCIDENTAL
DAMAGES, THE ABOVE LIMITATION MAY NOT
APPLY TO YOU.

Lassen SQ GPS Receiver v
Contents
1StarterKit
Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Starter Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Removing the Lassen SQ GPS Module . . . . . . . . . . . . . . 4
Receiver Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Interface Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
TSIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
NMEA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Ordering Starter Kit Components. . . . . . . . . . . . . . . . . . . . . 7
Starter Kit Interface Unit . . . . . . . . . . . . . . . . . . . . . . . . . 8
Serial Port Interface . . . . . . . . . . . . . . . . . . . . . . . 11
Pulse-Per-Second (PPS) . . . . . . . . . . . . . . . . . . . . . 12
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Hardware Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Software Toolkit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2 Hardware Integration
General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Digital IO/Power Connector . . . . . . . . . . . . . . . . . . . 21
RF Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Digital IO/Power Connector Pinout . . . . . . . . . . . . . . . 24
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Contents
vi Lassen SQ GPS Receiver
Pulse-Per-Second (PPS). . . . . . . . . . . . . . . . . . . . . . . . . 28
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
GPS Antennas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3 Software Interface
Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Communicating with the Lassen SQ GPS receiver Module . . . . . . 35
Software Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Port Configuration . . . . . . . . . . . . . . . . . . . . . . . . 35
Port Protocol and Data Output Options. . . . . . . . . . . . . . . . . 37
Protocol Configuration and Interface . . . . . . . . . . . . . . 37
TSIP Data Output Modes . . . . . . . . . . . . . . . . . . . . 38
Automatic TSIP Output Options and Defaults. . . . . . . . . . 38
Automatic TSIP Output Packets (fixed rate). . . . . . . . . . . 39
Packet Output Order . . . . . . . . . . . . . . . . . . . . . . . 40
NMEA 0183 Protocol and Data Output Options. . . . . . . . . 41
Custom Port Configuration . . . . . . . . . . . . . . . . . . . . . . . 42
Timing Applications . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Extended GPS Week Number . . . . . . . . . . . . . . . . . . 46
4 Operation and Performance
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
GPS Satellite Message . . . . . . . . . . . . . . . . . . . . . . . . . 49
Satellite Acquisition and Time to First Fix . . . . . . . . . . . . . . . 50
Cold-Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Warm Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Hot Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Garage Search Strategy . . . . . . . . . . . . . . . . . . . . . 52
System Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Satellite Mask Settings . . . . . . . . . . . . . . . . . . . . . . . . . 54
Elevation Mask. . . . . . . . . . . . . . . . . . . . . . . . . . 55
SNR Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
DOP Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Contents
Lassen SQ GPS Receiver vii
PDOP Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Standard Operating Modes . . . . . . . . . . . . . . . . . . . . . . . 57
Fix Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Position Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Coordinate Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
TSIP Coordinate Systems . . . . . . . . . . . . . . . . . . . . 59
NMEA 0183 . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . 61
Update Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Dynamic Limits . . . . . . . . . . . . . . . . . . . . . . . . . 61
Re-Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . 62
GPS Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Serial Time Output . . . . . . . . . . . . . . . . . . . . . . . . 64
Pulse-Per-Second (PPS) . . . . . . . . . . . . . . . . . . . . . 64
System Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . 65
A Trimble Standard Interface Protocol (TSIP)
Interface Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Packet Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Automatic Output Packets . . . . . . . . . . . . . . . . . . . . . . . 70
Customizing Receiver Operations . . . . . . . . . . . . . . . . . . . 71
Automatic Position and Velocity Reports. . . . . . . . . . . . . . . . 71
Initialization Packets to Speed Start-up. . . . . . . . . . . . . . . . . 72
Packets Output at Power-Up . . . . . . . . . . . . . . . . . . . . . . 73
Timing Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Satellite Data Packets . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Backwards Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 74
Recommended TSIP Packets . . . . . . . . . . . . . . . . . . . . . . 75
Command Packets Sent to the Receiver . . . . . . . . . . . . . . . . 76
Report Packets Sent by the Receiver to the User . . . . . . . . . . . . 78
Key Setup Parameters or Packet BB . . . . . . . . . . . . . . . . . . 79
Set Fix Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Dynamics Code . . . . . . . . . . . . . . . . . . . . . . . . . 81

Contents
viii Lassen SQ GPS Receiver
Elevation Mask. . . . . . . . . . . . . . . . . . . . . . . . . . 81
Signal Level Mask . . . . . . . . . . . . . . . . . . . . . . . . 82
DOP Mask and Switch . . . . . . . . . . . . . . . . . . . . . . 83
Packet Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Command Packet 0x1E - Clear Battery Backup, then Reset. . . 84
Command Packet 0x1F - Request Software Versions . . . . . . 85
Command Packet 0x21 - Request Current Time. . . . . . . . . 85
Command Packet 0x23 - Initial Position
(XYZ Cartesian ECEF) . . . . . . . . . . . . . . . . . . 85
Command Packet 0x24 - Request GPS Position Fix Mode . . . 86
Command Packet 0x25 - Initiate Soft Reset & Self Test . . . . 86
Command Packet 0x26 - Request Health . . . . . . . . . . . . 86
Command Packet 0x27 - Request Signal Levels. . . . . . . . . 86
Command Packet 0x2A - Altitude for 2-D Mode . . . . . . . . 86
Command Packet 0x2B - Initial Position . . . . . . . . . . . . 88
Command Packet 0x2D - Request Oscillator Offset. . . . . . . 88
Command Packet 0x2E - Set GPS Time . . . . . . . . . . . . . 89
Command Packet 0x31 - Accurate Initial Position . . . . . . . 90
Command Packet 0x32 - Accurate Initial Position, . . . . . . . 91
Command Packet 0x35 - Set/Request I/O Options . . . . . . . 92
Command Packet 0x37 - Request Last Position and Velocity . . 95
Command Packet 0x38 - Request/Load Satellite System Data . 95
Command Packet 0x3C - Request Current Satellite Tracking . 97
Report Packet 0x41 - GPS Time . . . . . . . . . . . . . . . . . 97
Report Packet 0x42 - Single-Precision Position Fix . . . . . . . 99
Report Packet 0x43 - Velocity Fix, XYZ ECEF . . . . . . . . . 100
Report Packet 0x45 - Software Version Information. . . . . . .101
Report Packet 0x46 - Health of Receiver . . . . . . . . . . . .102
Report Packet 0x47 - Signal Levels for all Satellites . . . . . .103
Report Packet 0x4A - 20 Byte Format . . . . . . . . . . . . . .104
Report Packet 0x4A - 9 Byte Format . . . . . . . . . . . . . .105
Report Packet 0x4B - Machine/Code ID and Additional Status. 106

Contents
Lassen SQ GPS Receiver ix
Report Packet 0x4D - Oscillator Offset . . . . . . . . . . . . .107
Report Packet 0x4E - Response to Set GPS Time . . . . . . . . 107
Report Packet 0x55 - I/O Options . . . . . . . . . . . . . . . .108
Report Packet 0x56 - Velocity Fix, East-North-Up (ENU) . . . 110
Report Packet 0x57 - Information About Last Computed Fix . . 111
Report Packet 0x58 - Satellite System Data/Acknowledge . . . 112
Report Packet 0x5C - Satellite Tracking Status . . . . . . . . . 116
Report Packet 0x6D - All-In-View Satellite Selection. . . . . . 118
Command Packet 0x70 - Filter Control . . . . . . . . . . . . .119
Report Packet 0x70. . . . . . . . . . . . . . . . . . . . . . . .120
Command Packet 0x7A . . . . . . . . . . . . . . . . . . . . .121
Report Packet 0x7B . . . . . . . . . . . . . . . . . . . . . . .122
Report Packet 0x82 - Differential Position Fix Mode . . . . . . 122
Report Packet 0x83 - Double-Precision XYZ Fix and Bias . . 123
Report Packet 0x84 - Double-Precision LLA Fix and Bias . . 124
Packets 0x8E and 0x8F - Superpacket . . . . . . . . . . . . . .124
Command Packet 0xBB - Navigation Configuration . . . . . . 125
Command Packet 0xBC - Protocol Configuration . . . . . . . . 126
TSIP Superpackets . . . . . . . . . . . . . . . . . . . . . . . . . . .128
Command Packet 0x8E-20 - Request Last Fix with Extra Info.. 128
Report Packet 0x8F-20 - Last Fix with Extra Info. (binary). . . 129
Command Packet 0x8E-26 - Non-Volatile Memory Storage . . 132
Report Packet 0x8F-26 - Non-Volatile Memory Status . . . . . 132
B TSIP Tool kit User’s Guide
SQ_Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134
Delta Position . . . . . . . . . . . . . . . . . . . . . . . . . .135
File Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . .135
C NMEA 0183
The NMEA 0183 Communication Interface . . . . . . . . . . . . . .138
NMEA 0183 Message Format . . . . . . . . . . . . . . . . . . . . .139
Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .140

Contents
xLassen SQ GPS Receiver
NMEA 0183 Message Options . . . . . . . . . . . . . . . . . . . . .142
NMEA 0183 Message Formats . . . . . . . . . . . . . . . . . . . . .143
GGA - GPS Fix Data. . . . . . . . . . . . . . . . . . . . . . .143
GLL - Geographic Position - Latitude/Longitude . . . . . . . . 144
GSA - GPS DOP and Active Satellites . . . . . . . . . . . . . 145
GSV - GPS Satellites inView . . . . . . . . . . . . . . . . . .146
RMC - Recommended Minimum Specific GPS/Transit Data . . 147
VTG - Track Made Good and Ground Speed . . . . . . . . . . 148
ZDA - Time & Date . . . . . . . . . . . . . . . . . . . . . . .149
Exception Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . .150
Power-up with No BBRAM . . . . . . . . . . . . . . . . . . .150
Power-up with BBRAM . . . . . . . . . . . . . . . . . . . . .150
Interruption of GPS Signal . . . . . . . . . . . . . . . . . . . .151
D Specifications and Mechanical Drawings
Lassen SQ GPS Receiver Specifications . . . . . . . . . . . . . . . .154
Performance . . . . . . . . . . . . . . . . . . . . . . . . . . .154
Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155
Environmental . . . . . . . . . . . . . . . . . . . . . . . . . .155
Physical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155
Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . .156
Ultra Compact Embedded Antenna. . . . . . . . . . . . . . . . . . .159
Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
LNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
Overall Specifications . . . . . . . . . . . . . . . . . . . . . .160
Storage Conditions. . . . . . . . . . . . . . . . . . . . . . . .160
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160
Compact Magnetic Mount Antenna. . . . . . . . . . . . . . . . . . .162
Antenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
LNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Overall Specifications . . . . . . . . . . . . . . . . . . . . . .163
Storage Conditions. . . . . . . . . . . . . . . . . . . . . . . .163

Contents
Lassen SQ GPS Receiver xi
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163
Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . .164
Compact Unpackaged Antenna . . . . . . . . . . . . . . . . . . . . .166
Glossary

Contents
xii Lassen SQ GPS Receiver

Lassen SQ GPS Receiver xiii
About this Manual
Welcome to System Designer Reference Manual for the Lassen SQ
GPS receiver. This manual describes how to integrate and operate the
Lassen SQ GPS receiver.
If you are not familiar with GPS, visit Trimble’s website,
www.trimble.com, for an interactive look at Trimble and GPS.
Trimble assumes that you are familiar with Microsoft Windows and
know how to use a mouse, select options from menus and dialogs,
make selections from lists, and refer to online help.
Technical Assistance
If you have a problem and cannot find the information you need in the
product documentation, contact the Trimble Technical Assistance
Center at 800-767-4822.
Your Comments
Your feedback about the supporting documentation helps us to
improve it with each revision. To forward your comments, send an e-
mail to [e-mail].

About this Manual
xiv Lassen SQ GPS Receiver

CHAPTER
1
Starter Kit 1
■Product Overview
■Starter Kit
■Receiver Performance
■Interface Protocols
■Ordering Starter Kit Components
■Starter Kit Interface Unit
■Power
■Hardware Setup
■Software Toolkit

1Starter Kit
2Lassen SQ GPS Receiver
1.1 Product Overview
The Lassen SQ GPS receiver is a full featured, ultra low power
receiver on a miniature form factor, suitable for a variety of mobile,
embedded applications. The Lassen SQ GPS receiver incorporates
Trimble’s FirstGPSTM architecture in the form of two ASICS:
Colossus RF down converter and IO-TS-C33 baseband chip. The IO-
TS-C33 integrates Trimble’s IO digital signal processor with the
Epson C33 RISC processor, real-time clock, UART, and 1Mbit
memory. Together with the colossus RF, this implementation of
FirstGPS technology makes possible one of the smallest
(26 mm x 26 mm x 6mm) and lowest power (100mW) GPS modules
available.
The Lassen SQ GPS receiver outputs a complete position, velocity,
and time (PVT) solution in the NMEA Version 3.0 ASCII protocol,
and the Trimble TSIP binary protocol. A Pulse-Per-Second signal is
available for very accurate timing applications.

Lassen SQ GPS Receiver 3
Starter Kit 1
1.2 Starter Kit
The Starter Kit makes it simple to evaluate the Lassen SQ GPS
receiver’s exceptional performance. The Starter Kit can be used as a
platform for configuring the receiver module and as a platform for
troubleshooting your design. The Starter Kit includes:
• Shielded Lassen SQ GPS module mounted on an interface
motherboard in a durable metal enclosure. The motherboard
accepts 9 - 32 VDC power and provides regulated +3.3V power
to the Lassen SQ GPS receiver. The motherboard also contains:
– 3.6V lithium battery that provides back-up power to the
receiver.
– Circuitry to convert the TTL output to RS-232, enabling
the user to connect the RS-232 port in the Starter Kit to the
PC COM port via an RS-232 cable connection.
• Compact Magnetic-Mount GPS Antenna with a 5 meter cable.
• Ultra-Compact Embedded Antenna with an 8 cm cable.
• 9-pin RS-232 interface cable.
• AC/DC power supply adapter (input: 100-240VAC,
output: 12 VDC).
• DC power cable.
• Cigarette lighter adapter power cable.
• CD containing software tools used to communicate with the
receiver, the System Designer Reference Manual, and “C”
programming source routines to be used as a template for
communicating with the receiver.

1Starter Kit
4Lassen SQ GPS Receiver
1.2.1 Removing the Lassen SQ GPS Module
The Lassen SQ GPS module is secured to the motherboard with
double-sided adhesive tape allowing for easy removal and integration
with the user’s application. (The adhesive tape used by Trimble is 3M
Scotch, part number 4945).
Follow these steps to remove the module from the motherboard:
• Unplug the I/O cable and the RF cable from the module.
• Use a small flat-head screw driver to pry the Lassen SQ GPS
receiver module off the motherboard.
Warning – Once the Lassen SQ GPS receiver module is removed from
the motherboard, the double-sided tape looses some of it’s adhesive
quality. This adhesive tape may only be re-used for laboratory testing. The
original adhesive tape should not be re-used for drive testing the Starter
Kit interface unit because the module could loosen and cause short circuit
when contacting other motherboard components. If drive testing is
required, use a new piece of double-sided adhesive tape to re-attach the
Lassen SQ GPS receiver module to the motherboard.

Lassen SQ GPS Receiver 5
Starter Kit 1
1.3 Receiver Performance
The Lassen SQ GPS receiver is a complete 8-channel parallel tracking
GPS receiver designed to operate with the L1 frequency, Standard
Position Service, Coarse Acquisition code. Using two highly
integrated Trimble custom integrated circuits, the receiver is designed
in a modular format especially suited for embedded applications
where small size and extremely low power consumption are required.
The receiver features Trimble's latest signal processing code, a high-
gain RF section for compatibility with standard 27 dB active gain GPS
antennas, and a CMOS TTL level pulse-per-second (PPS) output for
timing applications or for use as a general purpose synchronization
signal.
The Lassen SQ GPS receiver acquires a position fix with minimal
delay after power cycling. The battery back-up RAM is used to keep
the Real Time clock (RTC) alive, and to store the following:
• Almanac
• Ephemeris
• Last position
User settings such as port parameters and NMEA settings can be
stored in the receiver’s non-volatile (Flash) memory. These settings
are retained without application of main power or battery back-up
power.
The Lassen SQ GPS receiver has a single configurable serial I/O
communication port.
Warning – When customizing port assignments or characteristics,
confirm that your changes do not affect your ability to communicate with
the receiver (see Chapter 3, Software Interface).

1Starter Kit
6Lassen SQ GPS Receiver
1.4 Interface Protocols
The Lassen SQ GPS receiver operates using one of two protocols —
Trimble Standard Interface Protocol (TSIP) or NMEA 0183. The
factory default setting for the I/O port is TSIP bi-directional. Protocol
selection and port characteristics are user configurable.
1.4.1 TSIP
TSIP is a powerful binary packet protocol that allows the system
designer maximum configuration control over the GPS receiver for
optimum performance in any number of applications. TSIP supports
over 20 commands and their associated response packets for use in
configuring the Lassen SQ GPS receiver to meet user requirements.
1.4.2 NMEA
NMEA 0183 is an industry standard protocol common to marine
applications. NMEA provides direct compatibility with other NMEA-
capable devices such as chart plotters, radars, etc. The Lassen SQ GPS
receiver supports most NMEA messages for GPS navigation. NMEA
messages and output rates can be user selected as required.