1. はじめに
The WITMOTION WT901B is a high-performance 10-axis Inertial Measurement Unit (IMU) sensor designed for precise attitude measurement. It integrates an accelerometer, gyroscope, angle sensor, magnetometer, barometer, and tilt sensor, utilizing advanced Kalman filtering for stable and accurate data output. This manual provides essential information for setting up, operating, and maintaining your WT901B sensor.

Image 1: The compact WITMOTION WT901B 10-Axis IMU Sensor, highlighting its small form factor and various sensing capabilities including 3-axis acceleration, 3-axis gyro, 3-axis angle, 3-axis magnetic field, quaternion, barometric pressure, altitude, port status, and time.
2 製品の特徴
- 高性能: Military-grade 10-axis sensor providing Pitch, Roll, Yaw (X, Y, Z axis), angular velocity, angle, magnetic field, atmospheric pressure, and height data. Selectable measurement range and output rate (0.2 - 200 Hz).
- 堅牢な設計: Features a Cortex-M0 core processor, highly integrated MEMS, and Kalman algorithm for 0.05-degree measurement accuracy (X, Y axes). Small size with diverse interface options for easy integration.
- 高度なアルゴリズム: Built-in R&D dynamic fusion algorithm and Kalman filtering ensure stable data output, excellent bias stability, and low noise for increased measurement accuracy.
- コンパクトサイズ: Easy to install in various applications.
- 6-axis/9-axis Free Switching: Allows flexibility in data output based on application needs.
- Range Automatic Switching: Automatically adjusts measurement range from 2g to 16g.
- UART接続: Supports TTL/IIC communication protocols.
3. 仕様
| パラメータ | 価値 |
|---|---|
| モデル | WT901B |
| ブランド | ウィットモーション |
| 巻tage | 3.3V〜5V |
| 現在 | <25mA |
| インタフェース | シリアルTTL/IIC(高速400Kをサポート) |
| 出力 | Acceleration, Gyro, Magnetic, Angle, Quaternion, Barometric Pressure, Altitude |
| 範囲 | Acceleration: ±2/4/8/16g (adaptive), Gyro: ±2000°/s, Magnetic: ±2Gauss, Angle: X, Z: ±180°, Y: ±90°, Baro: 300~1100hPa |
| 角度精度 | X, Y axis: 0.2°, Z axis: 1° (after calibrated, no magnetic field interference) |
| 返品率 | 0.2~200Hz (default: 10Hz) |
| ボーレート | 4800~230400bps (default: 9600bps) |
| 加速解像度 | ±2g: 0.061mg/LSB (16384LSB/g), ±4g: 0.12mg/LSB (8192LSB/g), ±8g: 0.25mg/LSB (4096LSB/g), ±16g: 0.5mg/LSB (2048LSB/g) |
| サイズ | 15.24×15.24×2mm / 0.6インチ×0.6インチ×0.08インチ |
| 動作温度 | -40℃~+85℃ |
| 取り付け | 方向: 水平 / 垂直 |
| 正味重量 | 1g |

Image 2: Detailed product parameters for the WT901B sensor, including electrical, performance, and physical specifications.
4. 箱の中身
パッケージを開封すると、次のアイテムが見つかります。
- 1 x WitMotion WT901B TTL Accelerometer Sensor
- 2 x Six Pin Male Connector (1 x 6)
- ウェルカムガイド1冊
Note: A USB-UART Converter is not included and may be required for certain setups.

Image 3: The WT901B sensor shown with its included connectors and welcome guide.
5. セットアップ
5.1.ハードウェア接続
The WT901B sensor supports both Serial TTL and IIC interfaces. Connect the sensor to your microcontroller (e.g., Arduino) or computer via a suitable USB-UART converter (not included) using the provided six-pin male connectors. Ensure correct pin assignments for VCC, GND, TX, RX (for TTL), or SDA, SCL (for IIC).

Image 4: An illustration of the WT901B's internal components and connection points, highlighting the copper interface, embedded MEMS sensor chip, 48MHz core MCU, and power chip for stable voltage供給。
5.2. ソフトウェアのインストール
To utilize the sensor, you will need to install the WITMOTION PC software and relevant drivers. You can find the tutorial link on the guide card inside the package or search for 'wit-motion.com' to download the full tutorial and software. The software provides tools for data visualization, configuration, and calibration.
5.3. 磁場校正
Magnetic field calibration is crucial for accurate heading data. Perform calibration in an environment free from magnetic interference (e.g., metal objects, speakers).
- Connect the sensor to your computer and open the WITMOTION PC software.
- Navigate to the 'Configuration' section.
- Select 'Magnetic Field' and then 'Ellipse Fitting Calibrate'.
- Click 'Start Calibrate'.
- Rotate the sensor slowly and smoothly through all three axes (X, Y, Z) to cover a full sphere of orientations. Ensure each axis points to the East direction during its rotation cycle.
- Once the calibration data forms a complete ellipse on the software's graph, click 'Finish Calibrate'.
Video 1: Demonstrates the magnetic field calibration process using the WITMOTION PC software, including the physical rotation of the sensor and the visual feedback on the software interface.

Image 5: Highlights four major features of the WT901B: compact size, 6-axis/9-axis free switching, range automatic switching (2g to 16g), and UART connection support (TTL/IIC).
6. 操作手順
6.1. PCソフトウェアの使用
The WITMOTION PC software provides a comprehensive interface for monitoring, configuring, and analyzing sensor data. It includes features such as:
- リアルタイムデータ表示: View Pitch, Roll, Yaw, acceleration, angular velocity, magnetic field, and other parameters in real-time.
- 3D Pose Visualization: Observe the sensor's orientation in a 3D model.
- データ記録: Record sensor data in various formats (bin, play, csv, txt) for later analysis.
- 設定メニュー: Adjust sensor parameters such as output rate, measurement range, and communication settings.
- Calibration Tools: Perform various calibrations, including magnetic field calibration.

Image 6: The WITMOTION PC software interface displaying real-time data updates and analysis for the attitude sensor system, including a dashboard, 3D view, configuration, curve display, and data record options.


図7: 例amples of the WITMOTION mobile application interface, showing a dashboard with a level indicator and real-time data graphs, and a 3D visualization of the sensor's orientation.
6.2. 二次開発
WITMOTION provides complete development materials and an SDK to facilitate secondary development with platforms like Arduino. This includes manuals, datasheets, protocols, and sampコード。

Image 8: An illustration showing a laptop displaying various development resources provided by WITMOTION, including manuals, SDKs, tutorials, datasheets, and protocols for platforms like Arduino and STM32.
7. メンテナンス
To ensure the longevity and optimal performance of your WT901B sensor, observe the following:
- Keep the sensor in a dry environment and avoid exposure to moisture or extreme temperatures outside its operating range (-40 °C to +85 °C).
- Protect the sensor from physical shock or impact.
- When performing magnetic field calibration, ensure the sensor is far away from any magnetic interference sources.
- Clean the sensor gently with a dry, soft cloth if necessary. Avoid using liquids or harsh chemicals.
8。 トラブルシューティング
If you encounter issues with your WT901B sensor, consider the following:
- データ出力なし: Verify all electrical connections are secure and correct. Ensure the correct COM port and baud rate are selected in the software.
- 不正確な読み取り: Perform a magnetic field calibration as described in Section 5.3. Ensure the sensor is not near strong magnetic fields or metal objects during operation. Check for proper mounting orientation.
- ソフトウェア接続の問題: Reinstall drivers and the WITMOTION PC software. Try a different USB port or USB-UART converter.
- 不安定なデータ: Ensure the sensor is mounted securely and not subject to excessive vibration. Verify the Kalman filter settings in the software.
さらに詳しいサポートについては、セクション 10 のサポート情報を参照してください。
9. Areas of Applications
The WT901B sensor is suitable for a wide range of applications requiring precise motion and orientation sensing:
- Machinery monitoring
- Smart farming equipment
- Robotics and automation
- Tower monitoring
- Virtual Reality (VR) systems
- Industrial control and measurement

Image 9: Visual representation of various application areas for the WT901B sensor, including machinery, smart farming, robotics, tower monitoring, automation, and VR.
10. 保証とサポート
WITMOTION provides comprehensive support for its products:
- 保証: 購入日より12ヶ月の保証。
- 顧客サービス: Lifetime friendly customer service from the WitMotion team.
- サポートリソース:
- The tutorial link is printed on the guide card inside the package.
- Search 'wit-motion.com' to download the full tutorial, software, and development resources.
- Contact support directly via email: support@wit-motion.com for personalized assistance.