Quectel LG77L EVB User manual

LG77L EVB User Guide
GNSS Module Series
Version: 1.0
Date: 2021-03-23
Status: Released

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Our aim is to provide customers with timely and comprehensive service. For any assistance,
contact our company headquarters:
Quectel Wireless Solutions Co., Ltd.
Building 5, Shanghai Business Park Phase III (Area B), No.1016 Tianlin Road, Minhang District, Shanghai
200233, China
Tel: [phone]
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Copyright
The information contained here is proprietary technical information of Quectel. Transmitting, reproducing,
disseminating and editing this document as well as using the content without permission is forbidden.
Offenders will be held liable for payment of damages.All rights are reserved in the event of a patent grant
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Copyright © Quectel Wireless Solutions Co., Ltd. 2021. All rights reserved.

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Safety Information
The following safety precautions must be observed during all phases of operation, such as usage, service
or repair of any terminal incorporating Quectel LG77L module. Manufacturers of the terminal should send
the following safety information to users and operating personnel, and incorporate these guidelines into all
manuals supplied with the product. Otherwise, Quectel assumes no liability for customers’ failure to comply
with these precautions.
Ensure that the product may be used in the country and the required environment,
as well as that it conforms to the local safety and environmental regulations.
Keep away from explosiveand flammable materials.The use of electronic products
in extreme power supply conditions and locations with potentially explosive
atmospheres may cause fire and explosion accidents.
The product must be powered by a stable voltage source, while the wiring must
conform to security precautions and fire prevention regulations.
Proper ESD handling procedures must be followed throughout the mounting,
handling and operation of any devices and equipment that incorporate the module
to avoid ESD damages.

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About the Document
Revision History
Document Information
Title
LG77L EVB User Guide
Subtitle
GNSS Module Series
Document Type
EVB User Guide
Document Status
Released
Version
Date
Description
-
2021-03-23
Creation of the document
1.0
2021-03-23
First official release

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Contents
Safety Information...................................................................................................................................... 3
About the Document.................................................................................................................................. 4
Contents...................................................................................................................................................... 5
Table Index.................................................................................................................................................. 6
Figure Index................................................................................................................................................ 7
1Introduction......................................................................................................................................... 8
2General Overview................................................................................................................................ 9
2.1. EVB KitAccessories .................................................................................................................. 9
2.2. Connecting Cables and Antenna to EVB................................................................................. 10
3Board User Interfaces....................................................................................................................... 11
3.1. EVB Top View............................................................................................................................11
3.2. Board User Interfaces...............................................................................................................11
4Using QCOM Tool to Communicate................................................................................................ 14
4.1. Communication via the Micro-USB Interface........................................................................... 14
5Using PowerGPS Tool to Test......................................................................................................... 15
5.1. COM Port and Baud Rate Setting............................................................................................ 15
5.1.1. Interface Explained ....................................................................................................... 16
5.2. PMTK Command Sending....................................................................................................... 17
5.3. Automatic TTFF Testing........................................................................................................... 18
6Firmware upgrade............................................................................................................................. 23
7Appendix A Reference...................................................................................................................... 27

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Table Index
Table 1: List of Accessories........................................................................................................................10
Table 2: Detailed EVB Interfaces............................................................................................................... 12
Table 3: J401 Pin Detailed Description......................................................................................................13
Table 4: PowerGPS Interface Explained.................................................................................................... 16
Table 5: Related Document........................................................................................................................ 27
Table 6: Terms and Abbreviations..............................................................................................................27

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Figure Index
Figure 1: EVB Kit Accessories .....................................................................................................................9
Figure 2: EVB and Accessories Assembly................................................................................................. 10
Figure 3: EVB Top View ..............................................................................................................................11
Figure 4: USB Ports ...................................................................................................................................14
Figure 5: COM Port Setting Interface of QCOM........................................................................................14
Figure 6: PowerGPS Main Interface (Not Connected) ..............................................................................15
Figure 7: PowerGPS Interface (Connected)..............................................................................................16
Figure 8: PMTK Command Sending via PowerGPS.................................................................................18
Figure 9: Disable These Options................................................................................................................19
Figure 10: Static TTFF Testing via PowerGPS.......................................................................................... 19
Figure 11: Select Reference Location........................................................................................................ 20
Figure 12: Click Use Mean Position...........................................................................................................20
Figure 13: Click Configuration.................................................................................................................... 21
Figure 14: Set TTFF Time-out (Sec)..........................................................................................................21
Figure 15: Click Run/Stop Button............................................................................................................... 22
Figure 16: Firmware Upgrade –Step 1......................................................................................................23
Figure 17: Firmware Upgrade –Step 2......................................................................................................24
Figure 18: Firmware Upgrade –Step 3......................................................................................................24
Figure 19: Firmware Upgrade –Step 4 and 5........................................................................................... 25
Figure 20: Firmware Upgrade –Step 6......................................................................................................25
Figure 21: Successful Firmware Upgrade .................................................................................................26

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1Introduction
This document provides information on how to develop and test the Quectel LG77L module using the
Evaluation Board (EVB). The EVB is a convenient tool that allows you to become familiar with the LG77L
module.
This document describes the interfaces on the EVB; how to test the module with the software tool
(PowerGPS); and how to upgrade the firmware.
The user guide is divided into several sections:
Chapter 2 provides the general overview of EVB Kit accessories;
Chapter 3 describes the EVB user interfaces;
Chapter 4 describes how to communicate with a module by using the QCOM tool;
Chapter 5 describes how to test the module by using the PowerGPS tool;
Chapter 6 describes how to upgrade the module;
Chapter 7 is an appendix, which summarizes the relevant documents, terms and abbreviations
appearing herein.

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2General Overview
2.1. EVB Kit Accessories
The EVB Kit includes: Evaluation Board (EVB),Active GNSS Antenna, Micro-USB Cable, USB Flash Drive,
Bolts and Coupling Nuts. The software tools are placed in the USB flash drive.
The EVB Kit accessories are shown in the figure below, and check Table 1 for details.
USB Cable
USB Flash Drive
Bolts and
Coupling Nuts
GNSS Antenna
EVB
Figure 1: EVB Kit Accessories

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Table 1: List of Accessories
2.2. Connecting Cables and Antenna to EVB
The connection between the EVB and its accessories is shown in the figure below. For detailed information
on how to connect the EVB and its accessories, refer to the instruction sheet inside the EVB Kit.
Figure 2: EVB and Accessories Assembly

Place the active GNSS antenna where it can detect the satellites with a clear view of the sky.
Items
Description
Quantity
EVB
Evaluation Board
Size: 60 mm ×70 mm
1
USB Cable
Micro-USB Cable
1
GNSS Antenna
Active GNSS Antenna
Request theAntenna Datasheet from your local FAE.
1
USB Flash Drive
USB Flash Drive (including the module-related
documents, tools, and drivers)
1
Instruction Sheet
A sheet of paper giving instructions on how to connect
the EVB, details on EVB accessories, and much more.
1
Other
Bolts and Coupling Nuts
4 pairs
NOTE

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3Board User Interfaces
3.1. EVB Top View
The EVB includes:
LG77L Module (U101), Antenna Connector (J301), Power Switch (S201), Micro-USB Connector (J102),
FORCE_ON Button (S402), RESET_N Button (S401), Indication LEDs (D402, D403), Test Points (J401).
EVB top view is shown in the figure below.
D402
TXD indication LED
J301
Antenna connector U101 LG77L module
S402
FORCE_ON button
S401
RESET_N button
D403
PPS indication LED
J401
Test points
S201
Power switch
J102
Micro-USB connector
Figure 3: EVB Top View
3.2. Board User Interfaces
The EVB interfaces are detailed in the table below.

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Table 2: Detailed EVB Interfaces
Test point distribution is shown below:
J401 Pin Assignment:
TXD
GND
RXD
JAM_DET
RESET_N
1PPS
FORCE_ON
ANT_OK
ANT_DET
ANT_OFF
Function
Interfaces
Description
Power Supply
J102
Micro-USB
Power supply input:
DC power supply: 4.5–5.5 V, typ. 5.0 V
Current capability should be >100 mA
User Interface
J102
Micro-USB
NMEAsentence output and command input
RF Input
J301
Antenna Connector
Support:
GPS L1 C/A
GLONASS L1
BeiDou B1I
Use with the antenna provided with the Kit
Signal Indication
D402
TXD Indication LED
Flash: The module is turned on successfully. Data
output from UART TXD pin.
Extinct or Bright: Failed to turn on the module.
D403
PPS Indication LED
Flash: Successful position fix.
The frequency is 1 Hz.
Extinct: No position fix.
Switches and Buttons
S201
Power Switch
Power the EVB on/off
S401
RESET_N
Short press the button to reset the module.
S402
FORCE_ON
Short press the button to wake up the module from
the backup mode.
Test Points
J401
Test Points
Pins are detailed in Table 3 below

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Table 3: J401 Pin Detailed Description
Pin Name
I/O
Description
TXD
DO
Transmits data
RXD
DI
Receives data
RESET_N
DI
Resets the module
FORCE_ON
DI
Wakes up the module from backup mode
ANT_DET
DI
Detects active antenna open-circuit
GND
-
Ground
JAM_DET
DI
Detects jamming signal
1PPS
DO
1 pulse per second
ANT_OK
DI
Detects active antenna short-circuit
ANT_OFF
DO
Controls active antenna power

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4Using QCOM Tool to Communicate
This chapter illustrates how to use the QCOM tool to communicate with the module via the Micro-USB
interface.
Find the QCOM tool on the USB flash drive in the EVB Kit, or request it from your local FAE.
4.1. Communication via the Micro-USB Interface
Step 1: Connect the EVB and the PC with a Micro-USB cable via the Micro-USB interface.
Step 2: Flip the power switch (S201) to ON position to power on the EVB.
Step 3: Plug in the USB flash driveto the PC and run the provided driver installer to install the USB driver.
Step 4: View the USB port numbers in the Device Manager, as shown in Figure 4 below.
Figure 4: USB Ports
Step 5: Install the QCOM tool provided by Quectel. The COM Port Setting interface of QCOM is shown
in Figure 5 below.
Figure 5: COM Port Setting Interface of QCOM
Step 6: Select the correct “COM Port” (USB Port shown in Figure 4 above).
Step 7: Set the correct “Baudrate” (default value: 9600 bps). For more details on QCOM usage, see
document [1].

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5Using PowerGPS Tool to Test
This chapter explains how to use the PowerGPS tool for checking the status of GNSS receivers, when
you are working with the EVB.
Find the PowerGPS tool on the USB flash drive in the EVB Kit, or request it from your local FAE.
5.1. COM Port and Baud Rate Setting
Step 1: Assemble the EVB accessories.
Step 2: Flip the power switch (S201) to ON position to power on the EVB.
Step 3: Start the PowerGPS (PowerGPS Trial 2.3.5 is used as an illustration in this document) and select
a correct COM port and baudrate (the module supports 9600 bps by default) at the bottom of the
interface, as shown in the figure below.
Figure 6: PowerGPS Main Interface (Not Connected)

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Step 4: Click the “Create Connection”button. The interface shown in the figure below appears
when the module is connected.
Figure 7: PowerGPS Interface (Connected)
5.1.1. Interface Explained
You can view GNSS information, such as CNR message, time, position, speed and precision in the
PowerGPS interface. To find out more about these parameters, see the following table.
Table 4: PowerGPS Interface Explained
Icon
Explanation
A satellite vehicle (SV) with PRN 65. If the SV is positioned
near the center of the Sky View, the SV elevation angle is
close to 90°.
Dark Blue means that this satellite is being tracked.
Light blue means that this satellite is not being tracked.

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5.2. PMTK Command Sending
The PowerGPS supports sending PMTK commands to control the module as shown in the figure below,
The PMTK command format includes only characters between ‘$’ and ‘*’, for example: PMTK869,0. The
checksum will be calculated and added automatically to complete the full NMEA format message.
PRN G28 carrier-to-noise ratio (CNR) is 49 dB/Hz.
G stands for a GPS satellite, B for a BeiDou satellite, and S
for an SBAS satellite.
Light blue column means that the navigation data of the
satellite is in use.
PRN B3 CNR is 42 dB/Hz.
White column indicates that the navigation data of this satellite
is not in use.
UTC time
Latitude degree
Longitude degree
Position fix
The number of satellites being used
Horizontal dilution of precision
Altitude based on WGS84 datum
UTC date
Fixing mode: No-fix, 3D or 2D SPS
Satellite being used
Position dilution of precision
Vertical dilution of precision
Receiver speed

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Figure 8: PMTK Command Sending via PowerGPS
5.3. Automatic TTFF Testing
The PowerGPS tool allows users to measure TTFF (Time to First Fix) under the following testing conditions:
Full cold start,
Cold start,
Warm start, or
Hot start.
Select the number of tests from 1, 10, 20, 100, 1000 and 10000. Click the “Run” button to start the test.
Click the “Stop” button to stop the test.
PowerGPS configuration steps for TTFF testing:
Step 1: Whenrunninga TTFF test, these options need tobe unchecked else it will affect the TTFF results.
These options include “System time aiding”, “Reference location aiding”, “EPO aiding”, “Q BD
EPO aiding”.
Click “Setting” menu to open the “Options” window and select “AGPS Agent”. Then you need
to disable these options as shown in the figure below. Finally click “OK”.

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Figure 9: Disable These Options
Step 2: Click “MTK” menu and click “Static TTFF Testing” to enter “Automatic TTFF Testing”as shown
in the figure below.
Figure 10: Static TTFF Testing via PowerGPS