QGNSS Guide

QGNSS is Quectel’s official Windows tool for interacting with their GNSS modules. It provides real-time satellite monitoring, configuration, NTRIP client connectivity, AGNSS data injection, and firmware updates through a Qt5-based GUI. Version 1.8 is the current release supporting all LC29H variants.

Tip

On Linux, the lc29h Python CLI provides equivalent functionality for monitoring, configuration, and NTRIP — no Windows required.

Features

• Standard NMEA sentence parsing and display
• RTCM3.x protocol message support
• Log file replay and analysis
• Real-time satellite signal visualization (sky view, signal bars, deviation map)
• AGNSS data download and injection
• Built-in NTRIP client for RTK corrections
• Firmware update capability
• NMEA-to-KML conversion and coordinate conversion utilities

User Interface

Main Window

The main window shows the menu bar, tool bar, and a central area for sub-windows displaying positioning data.

Key Sub-Windows

Data Dock

Displays longitude, latitude, altitude, fix mode, and other positioning details in a structured panel.

Signal Level

Bar chart of C/N0 values per satellite, grouped by constellation. Transparent bars indicate satellites not currently tracked.

Sky View

Polar plot showing azimuth and elevation of visible satellites per constellation, with satellite counts.

Deviation Map

Position scatter plot relative to the first fix. Supports CEP circle display, average point marking, and RTK-vs-normal differentiation (green vs blue).

Text/Binary Data — Raw NMEA text and binary protocol output with timestamp, pause, and filter controls.

Messages View — Parsed NMEA fields displayed in a structured parameter table.

Configuration View — GUI for modifying receiver configuration parameters (varies by module variant).

Tool Bar Quick Access

Button	Function
Connect	Serial port connect/disconnect
Set Device Information	Select module and serial parameters
Open	Play log file
Cold/Warm/Hot/Full Cold Start	Send restart commands
Command Console	Open command console
GNSS Signal View	Signal level bars
Sky View	Polar satellite plot
Deviation Map	Position scatter plot
Data Dock	Positioning detail panel
NTRIP Client	RTK correction client

Common Operations

Connect to Receiver

1. Launch QGNSS
2. Click Set Device Information in the tool bar
3. Select the module type (e.g., LC29HAA, LC29HBA) and serial port parameters
4. Click OK, then click Connect

Note

Configure serial port parameters before connecting. The LC29H defaults to 115200 baud on UART1 and 460800 on USB.

Restart Receiver

Use the tool bar buttons to send restart commands:

Restart Type	Effect
Hot Start	Uses stored ephemeris, position, and time — fastest restart
Warm Start	Uses stored position and time but re-acquires ephemeris
Cold Start	Clears ephemeris and position, keeps configuration
Full Cold Start	Clears everything including configuration — slowest restart

Log Replay

1. Click Open (play button) in the tool bar
2. Select a .log, .txt, or .nma file
3. Use the play controller to adjust read rate, play/pause, and seek

TTFF Testing

1. Open Tools > Static TTFF Testing
2. Choose a restart type (cold, warm, hot)
3. Set the number of test cycles and timeout per test
4. Click Run to begin automated TTFF measurement

Results are saved to TTFF_xxx_xxx.log in the log folder.

Configure Receiver

1. Open View > Configuration View
2. Select parameters to modify
3. Click Generating code to preview the PAIR/PQTM commands
4. Click Send to apply to the receiver
5. Use Poll to query current configuration values

Send Commands

Open Tools > Command Console to send raw NMEA commands:

Control	Function
Enter	Appends \r\n to the command
HEX	Sends binary data instead of ASCII
Delay (ms)	Delay between sequential commands
Checksum	Auto-calculates NMEA checksum for commands
Run	Sends selected commands in a loop
Save/Load	Persist/restore command sets to config files

Send AGNSS Data

1. Open AGNSS > Assistant GNSS Online
2. Click Connect to reach Quectel’s FTP server
3. Select and download the AGNSS data file (EPO)
4. Choose Using UTC time (from receiver) or enter time manually
5. Enter position information or click Use Current Position
6. Select a restart type
7. Check Position and AGNSS Data, then click Reset and Transfer

Tip

AGNSS data improves Time to First Fix by providing predicted satellite orbits. On Linux, use lc29h agnss for equivalent functionality.

Connect to NTRIP Server

1. Open Tools > NTRIP Client
2. Enter the NTRIP caster address, port, username, and password
3. Click Update NTRIP source table to fetch available mount points
4. Select a mount point and set the request interval
5. Optionally enable Use manual position for a fixed base coordinate
6. Toggle Connect to Host to start receiving RTK corrections

Firmware Download

1. Connect to the receiver first (see above)
2. Open Tools > Firmware Download
3. Click the file selector to choose the firmware binary
4. Click the download button and wait for completion
5. Reset the module after the download finishes

Caution

Firmware update procedures vary by module variant. Refer to the variant-specific firmware upgrade guide before proceeding.

Built-in Utilities

NMEA to KML Converter

Converts NMEA log files to KML format for viewing tracks in Google Earth or other GIS tools.

1. Open Tools > NMEA Convert KML
2. Select the input NMEA file(s)
3. Choose the output file location
4. Click OK

Coordinate Converter

Converts between four coordinate formats:

• LLA (Deg) — Decimal degrees
• LLA (Deg, Min) — Degrees and decimal minutes
• LLA (Deg, Min, Sec) — Degrees, minutes, and seconds
• ECEF (XYZ) — Earth-Centered Earth-Fixed Cartesian

Dead Reckoning Status (BA/CA)

The DR tab displays Dead Reckoning calibration status for BA and CA variants, including IMU sensor state, calibration progress, and DR/GNSS fusion mode.

Linux Alternative

QGNSS is Windows-only. For Linux and macOS users, the lc29h Python package provides:

QGNSS Feature	lc29h Equivalent
Serial monitor	lc29h monitor
Satellite view	lc29h satellites
Configuration	lc29h config
NTRIP client	lc29h ntrip
AGNSS injection	lc29h agnss
Command console	lc29h send-command
Firmware version	lc29h version
Restart commands	lc29h restart

See the Python CLI guide and MCP Server guide for details.