1. Introduction
The Waveshare LC76G is a compact and high-performance Multi-GNSS (Global Navigation Satellite System) module designed for precise positioning applications. It supports a wide range of satellite systems including GPS, BeiDou (BDS), GLONASS, Galileo, and QZSS, ensuring robust and accurate location data. This module integrates a built-in Low-Noise Amplifier (LNA) for enhanced reception sensitivity and supports both UART and I2C communication interfaces, making it versatile for various embedded projects. It also features EPO (Extended Predictive Orbit) and EASY (Embedded Assist System) functions for faster time-to-first-fix (TTFF) and improved performance.
This manual provides essential information for setting up, operating, and maintaining your LC76G Multi-GNSS Module.
2. Package Contents
Verify that all items listed below are present in your package:
Image: Package contents showing the LC76G GNSS Module and an MX1.25 8PIN cable.
- 1x LC76G GNSS Module
- 1x MX1.25 8PIN cable
3. Key Features
The LC76G GNSS Module offers the following key features:
Image: Visual representation of the LC76G GNSS module with its main features listed.
- Supports Multi-GNSS systems: GPS, BeiDou (BDS), GLONASS, Galileo, and QZSS.
- Supports UART and I2C communication interfaces.
- Built-in Low-Noise Amplifier (LNA) for improved reception sensitivity.
- Supports EPO (Extended Predictive Orbit) and EASY (Embedded Assist System) functions for faster acquisition.
- Supports 1PPS (One Pulse Per Second) output for precise timing.
- UART communication baud rate: Configurable from 9600 to 921600bps (default 115200bps).
- Onboard rechargeable Li battery (MS621FE) for preserving ephemeris information and enabling hot starts.
- Two LEDs for indicating module working status (Power and PPS).
- Comes with online development resources and manual examples for various platforms (Raspberry Pi, Raspberry Pi Pico, Jetson Nano, Arduino, ESP32).
4. Pinout Definition
Understanding the pinout is crucial for proper integration of the LC76G module with your host device.
Image: Detailed diagram of the LC76G module's components and pinout, including the GH1.25 8PIN connector.
| Pin | Description |
|---|---|
| VCC | Power supply (3.3V/5V) |
| GND | Ground |
| TX | Connect to MCU.RX (Signal direction: TX >> MCU.RX) |
| RX | Connect to MCU.TX (Signal direction: MCU.TX >> RX) |
| PPS | GPS status indicator / 1PPS output |
| RST | Reset Pin |
| SDA | I2C data pin |
| SCL | I2C clock pin |
5. Specifications and Parameters
The following table outlines the key technical specifications and performance parameters for the LC76G GNSS Module.
Image: Detailed comparison of technical parameters for LC76G and L76K GNSS modules.
| Parameter | LC76G(AB) |
|---|---|
| GNSS | GPS/GLONASS/Galileo/BDS/QZSS |
| Chip Platform | AG3352 |
| L1 Band Receiver | 47 Tracking channels |
| SBAS | Support |
| A-GNSS | Support |
| Acquisition Sensitivity | -147dBm |
| Re-acquisition Sensitivity | -159dBm |
| Tracking Sensitivity | -166dBm |
| Cold Starts | 26s, Autonomous; 12s, With EASY™; 5s, With EPO™ |
| Warm Starts | 20s, Autonomous; 2s, With EASY™ |
| Hot Starts | 1s |
| Position Accuracy | 1.5m CEP |
| Speed Accuracy | 0.1m/s |
| Acceleration Accuracy (MAX) | 0.1m/s² |
| Timing Accuracy | 30ns |
| Update Rate (MAX) | 10Hz |
| I2C Rate | 400Kbps (Max) |
| UART Baudrate | Range: 9600-921600bps; Default: 115200bps |
| GNSS Data Update Rate | Max: 10Hz; Default: 1Hz |
6. Compatible Platforms
The LC76G module is designed for broad compatibility, supporting integration with various popular development platforms.
Image: Visual representation of the LC76G module's compatibility with multiple development boards.
The module is compatible with platforms such as:
- Raspberry Pi
- Raspberry Pi Pico
- Jetson Nano
- ESP32
- Arduino
7. Product Overview and Dimensions
A visual overview of the LC76G module and its physical dimensions.
Image: Top view of the LC76G GNSS module, showing the ceramic antenna.
Image: Two angled views of the LC76G GNSS module, showcasing its compact design.
Outline Dimensions
Image: Technical drawing illustrating the physical dimensions of the LC76G module in millimeters.
- Dimensions: Approximately 30.50mm x 25.50mm x 2.25mm (excluding antenna cable and connector height).
8. Setup Instructions
Follow these steps to set up your LC76G Multi-GNSS Module:
- Power Supply: Connect the VCC pin to a 3.3V or 5V power source and the GND pin to ground. Ensure the power supply is stable and within the specified voltage range.
- Communication Interface:
- UART: Connect the module's TX pin to your host MCU's RX pin, and the module's RX pin to your host MCU's TX pin. Configure your host MCU's UART to the desired baud rate (default 115200bps).
- I2C: Connect the module's SDA pin to your host MCU's SDA pin, and the module's SCL pin to your host MCU's SCL pin. Ensure appropriate pull-up resistors are used if not already present on your host board.
- Antenna: The module includes an integrated ceramic antenna. Ensure the module has a clear view of the sky for optimal satellite reception. Avoid placing it near metal objects or other sources of interference.
- Optional Connections:
- PPS: If precise timing is required, connect the PPS pin to an input on your host MCU.
- RST: The RST pin can be connected to a GPIO on your host MCU for software-controlled resets.
- Initial Power-Up: Once connections are secure, apply power. The PWR LED should illuminate. The PPS LED will blink once a valid GPS fix is acquired.
9. Operating Instructions
The LC76G module outputs NMEA 0183 sentences, which are standard for GNSS receivers. These sentences contain information such as latitude, longitude, altitude, speed, and satellite status.
- Data Reception:
- UART: Read data from the module's TX pin using your host MCU's UART receiver. The data will be a stream of NMEA sentences.
- I2C: Access the module's data registers via the I2C interface. Refer to the detailed communication protocol in the online documentation for specific register addresses and data formats.
- NMEA Sentence Parsing: Implement NMEA parser code on your host MCU to extract meaningful data from the received sentences. Common sentences include GPGGA (Global Positioning System Fix Data), GPRMC (Recommended Minimum Specific GNSS Data), and GPVTG (Track Made Good and Ground Speed).
- Configuration: The module can be configured using specific NMEA commands sent via the UART or I2C interface. This allows adjustment of parameters such as update rate, enabled GNSS constellations, and output sentence types. Refer to the Waveshare online resources for detailed command sets.
- 1PPS Output: The 1PPS signal provides a highly accurate pulse once per second, synchronized with UTC time. This is useful for applications requiring precise time synchronization.
- Hot Start / Warm Start: The onboard rechargeable battery helps retain ephemeris data, allowing for faster position fixes (warm or hot starts) after a brief power loss or restart.
For detailed programming examples and libraries for specific platforms (Raspberry Pi, Arduino, etc.), please consult the official Waveshare online development resources.
10. Maintenance
The LC76G Multi-GNSS Module is designed for reliable operation with minimal maintenance. Observe the following guidelines:
- Environmental Conditions: Operate the module within its specified temperature and humidity ranges. Avoid exposure to extreme temperatures, direct sunlight, moisture, or corrosive environments.
- Physical Handling: Handle the module with care to prevent physical damage. Avoid bending or stressing the PCB or connectors.
- Cleaning: If necessary, gently clean the module with a soft, dry cloth. Do not use liquid cleaners or solvents.
- Antenna Placement: Ensure the integrated antenna has an unobstructed view of the sky for optimal performance. Avoid covering the antenna with metallic objects or placing it near sources of electromagnetic interference.
- Battery Life: The onboard MS621FE battery is rechargeable and designed for long life. If the module consistently experiences cold starts after short power cycles, the battery may need to be charged by keeping the module powered for an extended period.
11. Troubleshooting
If you encounter issues with your LC76G module, consider the following troubleshooting steps:
- No Power LED:
- Check power connections (VCC and GND) and ensure the power supply is providing the correct voltage (3.3V or 5V).
- Verify the power supply is capable of providing sufficient current.
- No PPS LED Blinking / No Fix:
- Ensure the module has a clear, unobstructed view of the sky. Indoor environments or areas with tall buildings can block satellite signals.
- Allow sufficient time for a cold start (up to 26 seconds or more in challenging conditions).
- Check for strong electromagnetic interference nearby.
- Verify the antenna is not covered or damaged.
- No Data Output (UART/I2C):
- UART: Double-check TX/RX connections (cross-over). Ensure the baud rate on your host MCU matches the module's baud rate (default 115200bps). Verify your UART receiver code is correctly implemented.
- I2C: Confirm I2C address, SDA/SCL connections, and pull-up resistors. Verify your I2C communication code.
- Ensure the module is powered and the PWR LED is on.
- Inaccurate Position Data:
- Ensure the module has a good satellite fix (PPS LED blinking steadily).
- Check for multipath interference (signals reflecting off buildings).
- Verify the module is configured to use all available GNSS constellations for best accuracy.
- Module Not Responding:
- Try resetting the module by momentarily pulling the RST pin low, or by power cycling it.
12. Warranty and Support
For warranty information, technical support, and access to the latest documentation, drivers, and example code, please visit the official Waveshare website or their dedicated product page for the LC76G Multi-GNSS Module.
Waveshare provides comprehensive online resources to assist with development and integration. These resources often include:
- Detailed datasheets and user manuals.
- Example code for various microcontrollers and single-board computers (e.g., Raspberry Pi, Arduino, ESP32).
- Forum or community support.
Contact information for technical support can typically be found on the Waveshare website.
