1. Introduction
The Witmotion WTGPS-02H is a low-power, high-precision Global Navigation Satellite System (GNSS) module designed for accurate positioning and orientation. It supports multi-satellite system concurrency, including BDS, GPS, GLONASS, Galileo, and QZSS, ensuring robust and reliable data acquisition across various environments.
This module features dual-antenna orientation, high sensitivity positioning, and integrated MEMS sensors to provide real-time 3-axis heading, tilt angle, and roll angle outputs. Its built-in Low Noise Amplifier (LNA) and Surface Acoustic Wave (SAW) filter enhance sensitivity and anti-interference performance, making it suitable for complex applications.
Typical applications include communication antennas, geological monitoring, precision vehicles, ship positioning, drones, smart agriculture, and wearable devices.
2. Specifications
2.1 General Parameters
| Parameter | Value |
|---|---|
| GNSS Module | WTGPS-02H |
| Coverage | Worldwide |
| Dimensions | 25*2.6*0.6cm |
| Weight | 50g |
| Operating Temperature | -40°C ~ +85°C |
| Storage Temperature | -40°C ~ +90°C |
| Antenna Type | Active or passive |
| Interface | Type-C, UART |
| Certification | CE* |
2.2 GNSS Performance
| Parameter | Value |
|---|---|
| Receiving Frequencies | BDS: B1, B1C* | GPS: L1 | GLONASS: G1 | Galileo: E1 | QZSS: L1 |
| Default Constellation | BDS+GPS+GLONASS+Galileo+QZSS |
| Heading Accuracy | 0.2° (1m baseline) |
| Tilt Angle Accuracy | 0.3° |
| Roll Angle Accuracy | 0.3° |
| Initialization Time | <60s |
| Horizontal Positioning Accuracy | 1.5mCEP |
| Vertical Positioning Accuracy | 3.5mCEP |
| 1 PPS Accuracy | ≤30ns@1σ |
| TTFF (AGNSS enabled) | Cold start: 12s, Warm start: 2s, Hot start: 1s |
| TTFF (AGNSS disabled) | Cold start: 26s, Warm start: 18s, Hot start: 1s |
| Sensitivity (Capture) | -148dBm |
| Sensitivity (Track) | -165dBm |
| Sensitivity (Recapture) | -160dBm |
2.3 Electrical & Dynamic Performance
| Parameter | Value |
|---|---|
| Antenna Power Supply | External power supply or module VDD_RF pin |
| Power Supply Range | 3.1V-3.6V (Typical 3.3V) |
| I/O Voltage | Typical 2.8V |
| Consumption (Normal mode @ 3.3V) | 89mA@capture, 89mA@track |
| Consumption (Power saving mode @ 3.3V) | 52uA@Backup mode |
| Dynamic Performance (Altitude) | 10000m |
| Dynamic Performance (Speed) | 500m/s |
| Dynamic Performance (Acceleration) | 4g |
| UART Baud Rate | 9600~921600bps (Default: 115200bps) |
| Protocol | NMEA0183 |
| Update Frequency | Default 1Hz, up to 10Hz |
3. Setup and Installation
3.1 Power Supply
The WTGPS-02H module requires a power supply within the range of 3.1V to 3.6V, with a typical operating voltage of 3.3V. Ensure your power source provides stable voltage within this range. The I/O voltage is typically 2.8V.
3.2 Antenna Connection
The module supports both active and passive antennas and features an external antenna interface with dual antenna inputs for enhanced orientation capabilities. Connect your chosen GNSS antennas securely to the designated ports on the module. Proper antenna placement with a clear view of the sky is crucial for optimal performance.
3.3 Data Interface
The module communicates via a Type-C interface and UART. The default UART baud rate is 115200bps, but it can be configured from 9600bps to 921600bps. Ensure your host system's UART settings match those of the module for proper data communication.
3.4 Development Resources
Comprehensive development kits are available, including a detailed manual, sample code, and PC software, to assist with integration and application development.
4. Operating Instructions
4.1 Data Output
The WTGPS-02H module outputs positioning orientation data, 3-Axis Heading, Tilt Angle, and Roll Angle. The data is transmitted using the NMEA0183 protocol. The default update frequency is 1Hz, configurable up to 10Hz.
4.2 PC Software (QGNSS V1.8)
The module is compatible with the free and useful QGNSS V1.8 PC software. This software allows for real-time viewing of GNSS data, including signal levels, data dock information (longitude, latitude, altitude, speed, fix mode, quality indicator, time, etc.), a sky view of visible satellites, and an online map for visual positioning.
5. User Tips
- For best accuracy, especially for heading and tilt, ensure both antennas have an unobstructed view of the sky and are mounted rigidly relative to each other.
- Utilize the provided PC software (QGNSS V1.8) to monitor signal quality and satellite visibility during initial setup and troubleshooting.
- When integrating into custom systems, refer to the sample code provided in the development kit for guidance on parsing NMEA0183 data and configuring UART communication.
- Consider the power-saving mode (52uA@Backup mode) for battery-operated applications to extend device longevity.
6. Maintenance
The WTGPS-02H module is designed for robust operation. To ensure its longevity and optimal performance:
- Environmental Protection: Avoid exposing the module to extreme moisture, corrosive substances, or temperatures outside its specified operating range (-40°C to +85°C).
- Physical Handling: Handle the module with care to prevent physical damage. Avoid dropping or subjecting it to strong vibrations.
- Cleaning: If necessary, gently clean the module with a dry, soft cloth. Do not use harsh chemicals or solvents.
- Firmware Updates: Check the official WitMotion website periodically for any available firmware updates that may improve performance or add new features.
7. Troubleshooting
7.1 No Data Output / Incorrect Readings
- Check Power: Ensure the module is receiving stable power within the 3.1V-3.6V range.
- Verify Connections: Confirm all antenna and UART connections are secure and correctly wired.
- Antenna Placement: Ensure antennas have a clear, unobstructed view of the sky. Obstructions can significantly degrade signal quality.
- UART Settings: Double-check that your host system's UART baud rate (e.g., 115200bps default) and other settings match the module's configuration.
- Initialization Time: Allow up to 60 seconds for the module to initialize and acquire a fix, especially during a cold start.
- Software Check: Use the QGNSS V1.8 PC software to diagnose signal strength, satellite visibility, and raw NMEA data output.
7.2 Poor Accuracy / Unstable Readings
- Environmental Interference: The module has built-in anti-interference features, but strong electromagnetic interference (EMI) from nearby electronics can still affect performance. Try relocating the module or shielding it.
- Antenna Quality/Type: Ensure you are using appropriate GNSS antennas. For dual-antenna orientation, the quality and spacing of the antennas are critical.
- Dynamic Conditions: In high-dynamic environments (e.g., rapid acceleration), temporary fluctuations in accuracy are normal. The module is rated for up to 4g acceleration and 500m/s speed.
8. Warranty and Support
WitMotion provides lifetime technical support for the WTGPS-02H module. For any technical inquiries, troubleshooting assistance, or support regarding the product, please contact WitMotion Shenzhen. Co.,Ltd directly through their official channels.
Please refer to the official WitMotion website or your purchase documentation for the most up-to-date contact information and warranty details.
