BZGNSS BZ-251 BZ-181 BZ-121 M10 GPS Module Instruction Manual

1. Introduction

The BZGNSS series of GPS modules (BZ-121, BZ-181, BZ-251) are cost-effective, high-performance positioning solutions designed for FPV, drone, and flight control applications. Featuring the 10th generation M10 chip, these modules offer fast satellite acquisition, extensive satellite coverage, and accurate positioning. The BZ-251 model further integrates a QMC5883 electronic compass for enhanced navigation capabilities. These modules are compatible with popular flight controllers such as F405 and F722, enabling advanced flight functions.

Figure 1: BZGNSS BZ-121, BZ-181, and BZ-251 GPS Modules

2. Models Overview

The BZGNSS GPS modules are available in three main models, each with distinct features:

• BZ-121 GPS: This is a single protocol GPS module without a built-in compass. It is the smallest and lightest in the series, weighing approximately 2.5g.
• BZ-181 GPS: Also a single protocol GPS module without a built-in compass. It is slightly larger than the BZ-121, weighing approximately 7.5g.
• BZ-251 GPS: This is a dual protocol GPS module that includes a built-in QMC5883 electronic compass. It is the largest and heaviest of the three, weighing approximately 11.5g, offering comprehensive navigation features.

All models utilize the 10th generation M10 chip for superior performance. The ceramic antenna on each module features an oil spraying process to prevent scratches and oxidation, ensuring durability and consistent performance.

3. Specifications

4. Setup and Installation

Proper installation and wiring are crucial for optimal performance of your BZGNSS GPS module. Always ensure your flight controller is powered off before making any connections.

4.1. Wiring Diagram (BZ-251 GPS Example)

The BZ-251 GPS module typically uses a 6-pin connector for communication and power. Refer to the diagram below for standard pin assignments:

Figure 2: BZ-251 GPS Module with Dimensions and Pinout

• TX (Transmit): Connect to the RX (Receive) pin of your flight controller's UART port.
• RX (Receive): Connect to the TX (Transmit) pin of your flight controller's UART port.
• GND (Ground): Connect to a Ground pin on your flight controller.
• 5V (Power): Connect to a 5V power output on your flight controller.
• SCL (Serial Clock): For BZ-251 (with compass), connect to the SCL pin of your flight controller's I2C port.
• SDA (Serial Data): For BZ-251 (with compass), connect to the SDA pin of your flight controller's I2C port.

4.2. Physical Installation

1. Select Module: Choose the appropriate GPS module (BZ-121, BZ-181, or BZ-251) based on the available space and desired features for your drone or FPV setup.
2. Mounting: Install the GPS module with the ceramic antenna facing upwards, ensuring an unobstructed view of the sky for optimal satellite reception. Secure it firmly to prevent movement during flight.
3. Connect Wiring: Connect the module to your flight controller according to the wiring diagram and your flight controller's specific pinout.

4.3. Firmware Configuration

• For BZ-121 and BZ-181: Betaflight (BF) firmware is generally recommended. Configure the UART port for GPS communication.
• For BZ-251: INAV firmware is recommended due to its support for GPS with integrated compass. Configure both the UART port for GPS and the I2C port for the QMC5883 compass.

5. Operation

Once installed and configured, the BZGNSS GPS module will begin acquiring satellite signals upon power-up. The indicator light on the module will typically illuminate blue when powered and actively searching for satellites. A solid blue light often indicates a successful GPS lock.

The M10 chip ensures fast star search and accurate positioning, providing reliable data for flight stabilization, return-to-home functions, and other GPS-dependent features of your flight controller.

6. Maintenance

The BZGNSS GPS modules are designed for durability, featuring a ceramic antenna with an oil spraying process to protect against scratches and oxidation. To ensure longevity and consistent performance:

• Keep the module clean and free from dust or debris.
• Avoid exposing the module to extreme physical shock or moisture.
• Regularly check wiring connections for any signs of wear or looseness.

7. Troubleshooting

If you encounter issues with your BZGNSS GPS module, consider the following troubleshooting steps:

• No GPS Lock: Ensure the module has a clear, unobstructed view of the sky. Verify all wiring connections (TX/RX, GND, 5V) are correct and secure. Check your flight controller's firmware configuration for proper GPS UART settings.
• Incorrect Compass Heading (BZ-251): Verify the I2C connections (SCL/SDA) are correct. Perform a compass calibration within your flight controller's software (e.g., INAV). Ensure the module is mounted away from strong magnetic fields (e.g., motors, power wires).
• No Indicator Light: Check the 5V power connection and ground. Ensure the flight controller is powered on.
• Intermittent Performance: Inspect for loose wires or damaged components. Ensure the module is securely mounted and not vibrating excessively.

8. User Tips

• For optimal satellite acquisition, power on your drone/FPV system and allow the GPS module to sit stationary in an open area for a few minutes before flight.
• Always double-check your flight controller's documentation for specific UART and I2C port assignments and configuration steps when integrating a new GPS module.
• The compact size and lightweight design of these modules make them ideal for smaller builds where space and weight are critical considerations.

9. Warranty and Support

For warranty information or technical support regarding your BZGNSS GPS module, please contact the seller or manufacturer directly. Ensure you retain your proof of purchase for any warranty claims.