1. Product Overview
The BZGNSS series of GPS modules (BZ-121, BZ-181, BZ-251) are high-performance positioning devices designed for FPV (First Person View) and fixed-wing drone applications. Featuring the new 10th generation u-blox M10050 chip, these modules offer accurate positioning, fast star acquisition, and support for multiple satellite constellations including GPS, GLONASS, BDS, GALILEO, SBAS, and QZSS.
The BZ-251 model includes an integrated QMC5883 compass module and supports both UBLOX and NMEA protocols, making it highly versatile. The BZ-121 and BZ-181 models focus on core GPS functionality without a compass, primarily supporting the UBLOX protocol for efficient star search.
2. Safety Information
⚠️ For recreation use only. Illegal modification of drones/planes is prohibited. Please also pay attention to the relevant laws and regulations on the use of drones/planes in your country/area to ensure legal use.
3. Package Contents
- BZGNSS GPS Module (BZ-121, BZ-181, or BZ-251, depending on selection)
- Connection Wire Harness (for BZ-181 and BZ-251)
Note: BZ-121 typically uses PCB pads for direct soldering and may not include a separate wire harness.
4. Specifications
The following table details the specifications for each BZGNSS GPS module variant:
| Feature | BZ-121 | BZ-181 | BZ-251 |
|---|---|---|---|
| Chip | u-blox M10050 (10th Generation Chip) | ||
| Satellite Pattern | GPS, GLONASS, BDS, GALILEO, SBAS, QZSS (Default: GPS+GLONASS+BDS joint positioning) | ||
| FLASH | Supported | ||
| Frequency | GPS L1, GLONASS L1, BDS L1, GALILEO E1, SBAS L1, QZSS L1 | ||
| Power | 5V | ||
| Size (LxWxH) | 12x16x4.5mm | 18x18x4.8mm (thinnest) 18x18x6mm (with terminal block) | 25x25x5.4mm (thinnest) 25x25x6mm (with terminal block) |
| Interface | PCB Pad | SH1.0 4Pin | SH1.0 6Pin |
| Weight | 2.2g | 6.9g | 11.6g |
| Antenna | Ultrathin Ceramic (oil spraying process) | Ultrathin Ceramic / Standard Ceramic | |
| Receiving Channels | 72 search channels | ||
| Compass | None | QMC5883 | |
| Baud Rate | 115200dps | ||
| Output Protocol | UBLOX | UBLOX | NMEA / UBLOX (Dual protocol) |
| Output Frequency | 1Hz-10Hz (Default 10Hz) | ||
| Speed Accuracy | 0.05m/s | ||
| Horizontal Positioning Accuracy | 2D ACC 1.5m (open air) | ||
| Receiving Sensitivity | Trace-162dBm / Capture -160dBm | ||
| Dynamic Characteristics | Altitude: 50000m, Speed: 500m/s, Acceleration: 4G | ||
| Operating Temperature | -40°C ~ +85°C | ||
| Storage Temperature | -40°C ~ +105°C | ||
Note: The comparative specification table image here provides a visual summary of these specifications.
5. Setup and Installation
5.1 Important Firmware Note
The GPS chip is a new 10th generation chip. For optimal performance, your flight controller needs to be running firmware version 4.29 or above. If your flight controller uses firmware below 4.29, the GPS module will operate using the NMEA protocol.
5.2 Antenna Orientation
Ensure the ceramic antenna is facing upwards for best signal reception.
Image: Proper orientation of the ceramic antenna ('This side up').
5.3 Wiring Diagrams
Connect the GPS module to your flight controller according to the specific model's pinout. Ensure correct voltage (5V) and data lines (TX/RX, SCL/SDA) are used.
BZ-121 Wiring
Image: BZ-121 GPS module with wire harness. Pinout is typically VCC, GND, TX, RX.
BZ-181 Wiring
Image: BZ-181 GPS module showing 18x18x8mm dimensions and 4-pin connector with labels: 5V, RX, TX, GND.
BZ-251 Wiring
Image: BZ-251 GPS module showing 25x25x8mm dimensions and 6-pin connector with labels: TX, RX, GND, 5V, SCL, SDA.
The BZ-251 features a dual-purpose interface, allowing for both direct soldering to PCB pads or connection via the provided SH1.0 6Pin socket for enhanced durability and ease of use.
6. Operating Instructions
Once correctly installed and powered, the BZGNSS GPS module will begin searching for satellites. Ensure the module has a clear view of the sky for optimal performance.
- Star Search: The module is designed for fast star acquisition, providing quick initial positioning.
- Positioning Accuracy: Expect 2D ACC 1.5m accuracy in open-air conditions.
- Output Frequency: The default output frequency is 10Hz, providing frequent position updates to your flight controller.
6.1 Indicator Lights
- TX Light: A flashing red light on the TX indicator signifies that the module is actively outputting data.
- PPS Lamp: This lamp remains off when the module is not positioned. After achieving a 3D fix (successful positioning), the red PPS lamp will begin to flash.
7. Troubleshooting
- No GPS Lock / Slow Lock:
- Ensure the module has an unobstructed view of the sky.
- Verify the antenna is oriented correctly (ceramic side up).
- Check all wiring connections for continuity and correct pinout.
- Confirm the flight controller firmware version is compatible (4.29+ recommended for 10th gen chip, otherwise NMEA protocol).
- Test in an open outdoor area, away from tall buildings or dense foliage.
- Incorrect Data Output:
- Verify the baud rate setting on your flight controller matches the module's 115200dps.
- Ensure the correct protocol (UBLOX or NMEA) is selected/configured on your flight controller, especially for the BZ-251.
- Compass Issues (BZ-251 only):
- Perform compass calibration as per your flight controller's instructions.
- Keep the module away from strong magnetic fields or power cables that could cause interference.
- Ensure the compass orientation in the flight controller software matches the physical orientation of the module.
- No Indicator Lights:
- Check power supply (5V) to the module.
- Verify all power connections are secure.
8. Maintenance
- Cleaning: Keep the module clean and free from dust and debris. Use a soft, dry cloth for cleaning.
- Environmental Protection: Avoid exposing the module to extreme moisture, direct sunlight for prolonged periods, or corrosive environments.
- Physical Protection: Handle the module with care to prevent physical damage to the antenna or PCB.
9. User Tips
- Pre-flight Check: Always perform a GPS lock check before flight, especially for FPV return-to-home or rescue functions.
- Firmware Compatibility: Double-check your flight controller's firmware version against the GPS module's requirements to ensure proper communication and functionality.
- Mounting: Mount the GPS module as far away as possible from other electronic components that might generate electromagnetic interference, such as ESCs or VTXs.
10. Warranty and Support
For warranty claims or technical support, please contact your retailer or the manufacturer directly. Keep your proof of purchase for any warranty-related inquiries.
