Quectel LC29HEA High Precision Centimeter Level RTK Module User Manual

1. Overview

The Quectel LC29H series comprises dual-band, multi-constellation GNSS modules designed for high-precision positioning. These modules support concurrent reception of all four major global GNSS constellations: GPS, BDS, Galileo, and GLONASS.

Unlike traditional GNSS modules that only track L1 signals, the LC29H series can receive and track a greater number of visible satellites across multiple bands. This capability significantly reduces the multipath effect in challenging urban environments and enhances positioning accuracy. Equipped with an internal Low Noise Amplifier (LNA) and a Surface Acoustic Wave (SAW) filter, the module offers improved sensitivity and robust anti-interference performance.

With dual-frequency support, the LC29H module achieves a Circular Error Probable (CEP) accuracy of 1 meter in autonomous mode and centimeter-level accuracy in its RTK (Real-Time Kinematic) capable variants. An optional Dead Reckoning (DR) function further ensures superior positioning performance, even in areas with weak or unavailable GNSS signals.

Built on a 12 nm technology receiver chip, the LC29H series incorporates advanced power management features, enabling low-power GNSS sensing and position fixes. This makes it an ideal solution for power-sensitive and battery-powered systems. Its combination of high-precision positioning and low power consumption makes the LC29H series perfectly suited for applications such as real-time tracking and services related to the sharing economy.

2. Key Features

Multi-GNSS engine for GPS, GLONASS, BDS, Galileo, and QZSS.
Concurrent reception of L1 and L5 GNSS band signals.
Integrated DR (Dead Reckoning) function (optional).
RTK (optional) providing sub-meter accuracy with fast convergence time and outstanding performance.
Integrated LNA for high sensitivity.
Integrated SAW filter for noise cancellation.
UART, I2C, and SPI* interfaces.
Integrated AGNSS (Assisted GNSS) function.
Integrated AIC (Active Interference Cancellation) and jamming function.

Quectel LC29H Series Key Features Summary — Figure 2.1: Summary of Key Features for Quectel LC29H Series.

3. Setup

This section details the physical setup and connections required for the LC29HEA module.

3.1 Module Components

Quectel LC29HEA Module with labeled components — Figure 3.1: LC29HEA Module with key components labeled, including Type-C port, UART pins, PPS, RST, Type-C/TTL switch, GNSS antenna connector, and positioning indicator light.

The module features the following interfaces:

Type-C Power Supply/Communication Port: Used for power input and data communication.
External Power Supply Serial Port: Alternative power input via pin headers.
UART (TXD, RXD, GND): Standard serial communication interface.
PPS (Pulse Per Second): Output for precise timing synchronization.
RST (Reset): Reset pin for module control.
Type-C/TTL Toggle Switch: To select between Type-C USB or TTL UART for data communication.
GNSS Antenna (SMA Male) Connector: For connecting an external L1 & L5 band GNSS antenna.
Positioning Indicator Light: Provides visual feedback on the module's positioning status.

3.2 Connecting the Module

Power Supply: Connect the module to a stable 5V power source. This can be done via the Type-C port using a standard USB cable or through the external power supply pin header.
Antenna Connection: Attach a compatible L1 & L5 band GNSS antenna to the SMA Male connector on the module. Ensure the connection is secure.
Communication:
- For Type-C communication, ensure the Type-C/TTL toggle switch is set to the 'Type-C' position.
- For TTL (UART) communication, set the toggle switch to the 'TTL' position and connect the TXD, RXD, and GND pins to the corresponding pins on your host system.
Host System Integration: Connect the module to your host system (e.g., flight controller, mobile station, development board) using the chosen communication interface.

Schematic diagram showing connection between RTK module and flight control — Figure 3.2: Schematic diagram illustrating the connection between the RTK module and a flight control system, showing wired connections for power and data.

4. Operation

This section describes how to operate the LC29HEA module for positioning and data acquisition.

4.1 Positioning Introduction with QGNSS Software

The LC29H module can fully receive signals from BeiDou, GPS, GLONASS, QZSS, and other multiple satellites, offering high receiving sensitivity. It can quickly achieve RTK fixed points with a differential server.

Using the official QGNSS software, you can quickly display the number of satellites, intuitively visualize signal strength, and observe the effect of RTK convergence time.

Screenshot of QGNSS V1.7 Sky View showing satellite distribution and positioning data — Figure 4.1: QGNSS V1.7 Sky View displaying satellite constellation and RTK fixed positioning renderings, including latitude, longitude, altitude, speed, HDOP, PDOP, fix mode, and quality indicator.

Screenshot of QGNSS V1.7 Signal Level showing signal strength for various GNSS bands — Figure 4.2: QGNSS V1.7 Signal Level indicating signal strength across different GNSS bands (L1, L5, E1, E5a, B1I, B2a) for various satellites.

4.2 RTK Service and RTCM Corrections

To achieve RTK functionality, you will need to access mobile services to obtain RTCM (Radio Technical Commission for Maritime Services) corrections. This typically involves purchasing a CORS (Continuously Operating Reference Station) account service (e.g., from China Mobile or Qianxun).

Once subscribed, access the server to upload GGA data and obtain RTCM base station benchmark data issued by the server. The QGNSS software or similar tools allow configuration of NTRIP (Networked Transport of RTCM via Internet Protocol) caster settings.

Screenshot of NTRIP Caster settings interface — Figure 4.3: NTRIP Caster settings interface for accessing RTCM corrections, showing fields for address, port, username, password, and mount point configuration.

4.3 Serial Port Data Output

After the LC29H module is powered on, it automatically outputs NMEA standard data via its serial port. Users can utilize GGA data from this output to determine the current RTK status of the module.

Screenshot showing NMEA standard data output from serial port — Figure 4.4: Example of NMEA standard positioning data printed via serial port, showing various NMEA sentences like GPGGA, GPGSA, GPGSV.

4.4 Flight Control Integration

When integrated with flight control software, the GPS device should be recognized. This recognition can typically be achieved by configuring the NMEA standard settings within the flight control software.

Screenshot of flight control software recognizing GPS device — Figure 4.5: Flight control software interface indicating GPS device recognition, with status messages like 'PreArm: Compass not calibrated' and 'GPS: 3D DGPS'.

5. Maintenance

To ensure the longevity and optimal performance of your Quectel LC29HEA module, follow these general maintenance guidelines:

Handle with Care: Electronic components are sensitive. Avoid dropping the module or subjecting it to physical shocks.
Keep Dry: Protect the module from moisture and humidity. Water damage can lead to irreversible malfunctions.
Cleanliness: Keep the module free from dust and debris. Use a soft, dry brush or compressed air for cleaning. Avoid using liquids or harsh chemicals.
Temperature: Operate and store the module within its specified temperature ranges to prevent damage.
Proper Connections: Always ensure that all connections (power, antenna, data) are secure and correctly oriented before powering on the module.

6. Troubleshooting

If you encounter issues with your LC29HEA module, refer to the following troubleshooting tips:

Problem	Possible Cause	Solution
No positioning fix or poor accuracy	Antenna not connected or faulty. Poor satellite visibility (indoors, obstructed view). Incorrect software configuration (e.g., NMEA settings). No RTCM corrections received (for RTK mode). Interference from other electronic devices.	Ensure antenna is securely connected and functional. Move the module to an open outdoor area with clear sky view. Verify NMEA standard settings in your host software. Check NTRIP caster settings and CORS account status. Relocate the module away from potential interference sources.
Module not recognized by host system	Incorrect Type-C/TTL switch setting. Driver issues on the host system. Faulty USB cable or UART connection. Power supply issue.	Ensure the Type-C/TTL switch matches your connection method. Install necessary drivers for the USB-to-serial converter. Try a different USB cable or verify UART wiring. Confirm the module is receiving stable 5V power.
No serial data output	Module not powered on. Incorrect serial port settings (baud rate, parity, stop bits). Communication interface not selected correctly.	Verify power supply. Check and adjust serial port settings in your terminal software. Ensure the Type-C/TTL switch is correctly set for your communication method.
Android system interface issues	Android device lacks compatible drivers or hardware interface. Application software not configured for module's output.	Verify Android device's compatibility with USB-to-serial or UART communication. Ensure your Android application is designed to parse NMEA data from the module.

7. Specifications

The following table outlines the technical specifications for the LC29HEA RTK Development Board:

Table of specifications for LC29HEA RTK Development Board — Figure 7.1: LC29HEA RTK Development Board Specifications, detailing various parameters like supply voltage, positioning accuracy, and communication interfaces.

Parameter	Value
Module Model	LC29HEA
Supply Voltage	5V (supports external pin header power supply and Type-C power supply)
Positioning Accuracy	RTK: 1cm+1ppm, independent positioning: 1m
Output Frequency	Maximum 10Hz
Communication Interface	Type-C/TTL
Frequency	GPS/QZSS: L1 C/A, L5 GLONASS: L1 Galileo: E1, E5a BDS: B1I, B2a
Default GNSS Constellations	GPS + GLONASS + Galileo + BDS + QZSS
Protocol	NMEA0183/RTCM3.x
Mobile/Base Station	Command configurable for mobile station/base station (default mobile station)
Current Consumption (@default GNSS Constellations, 3.3V)	Normal Operation: 30mA@Acquisition 30mA@Tracking Power Saving Modes: 22uA (0.073mW)@Backup Mode
Dimension	47.5mm * 31.4mm
4G Communication	Optional 4G mobile station version access differential platform

Diagram showing dimensions of the LC29H module — Figure 7.2: LC29H Module Dimensions (16.0mm x 12.2mm x 2.5mm for the core module, not the development board).

8. User Tips

High Accuracy: Users have reported achieving RTK accuracy of approximately 2cm, confirming the module's high-precision capabilities.
NTRIP Corrections: For optimal RTK performance, ensure you have a reliable NTRIP caster service configured to receive RTCM corrections.
Host System Compatibility: When integrating with a host system like Android, verify that your system can interface with the module's communication protocols (UART, I2C, SPI, Type-C/TTL).
Functional Equipment: Ensure all components, including the module, antenna, and cables, are in good working order for reliable operation.

9. Warranty and Support

For warranty information, technical support, or service inquiries regarding your Quectel LC29HEA module, please contact the seller or the official Quectel support channels. Keep your purchase records handy for any warranty claims.

Quectel LC29HEA