AHRS IMU Sensor | WT901
The Robust Acceleration, Angular velocity, Angle & Magnetic filed Detector
Introduction
The WT901 is an AHRS IMU sensor device, detecting acceleration, angular velocity, angle, and magnetic field. Its robust housing and small outline make it perfectly suitable for industrial applications such as condition monitoring and predictive maintenance. Configuring the device enables the customer to address a broad variety of applications by interpreting the sensor data using smart algorithms and Kalman filtering.
WT901's scientific name is AHRS IMU sensor. A sensor measures 3-axis angle, angular velocity, acceleration, and magnetic field. Its strength lies in the algorithm which can calculate three-axis angle accurately. WT901 is employed where the highest measurement accuracy is required.
WT901 offers several advantages over competing sensors:
- Heated for best data availability: new WITMOTION patented zero-bias automatic detection calibration algorithm outperforms traditional accelerometer sensors.
- High precision Roll Pitch Yaw (X Y Z axis) Acceleration + Angular Velocity + Angle + Magnetic Field output.
- Low cost of ownership: remote diagnostics and lifetime technical support by WITMOTION service team.
- Developed tutorial: providing manual, datasheet, Demo video, free software for Windows computer, APP for Android smartphones, and sample code for MCU integration including 51 serial, STM32, Arduino, Matlab, Raspberry Pi, communication protocol for project.
- WITMOTION sensors have been praised by thousands of engineers as a recommended attitude measurement solution.
Built-in Sensors
Accelerometer: Icon representing a 3-axis accelerometer, showing rotational movement around X, Y, and Z axes.
Gyroscope: Icon representing a gyroscope, depicted as a circular dial with a needle, indicating rotation measurement.
Magnetometer: Icon representing a magnetometer, shown as a compass rose, indicating magnetic field detection.
Tutorials and Support
Tutorial Link
Contact
Applications
- AGV Truck
- Platform Stability
- Auto Safety System
- 3D Virtual Reality
- Industrial Control
- Robot
- Car Navigation
- UAV
- Truck-mounted Satellite Antenna Equipment
2 Features
- The default baud rate of this device is 9600 and could be changed.
- The interface of this product only leads to a serial port.
- The module consists of a high precision gyroscope, accelerometer, and geomagnetic field sensor. The product can solve the current real-time motion posture of the module quickly by using the high-performance microprocessor, advanced dynamic solutions, and Kalman filter algorithm.
- The advanced digital filtering technology of this product can effectively reduce the measurement noise and improve the measurement accuracy.
- Maximum 200Hz data output rate. Output content can be arbitrarily selected, the output speed 0.2Hz~200Hz adjustable.
3 Specification
3.1 Parameter
| Parameter | Specification |
|---|---|
| ▶ Working Voltage | 3.3V-5V |
| ▶ Current | <25mA |
| ▶ Size | 15.24mm x 15.24mm X 2.54mm |
| ▶ Data | Angle: X Y Z, 3-axis Acceleration: X Y Z, 3-axis Angular Velocity: X Y Z, 3-axis Magnetic Field: X Y Z, 3-axis Time, Quaternion |
| ▶ Output frequency | 0.2Hz--200Hz |
| ▶ Interface | Serial TTL level |
| ▶ Baud rate | 4800,9600(default),19200,38400,57600,115200,230400 |
Measurement Range & Accuracy
| Sensor | Measurement Range | Accuracy/ Remark |
|---|---|---|
| ▶ Accelerometer | X, Y, Z, 3-axis ±16g | Accuracy: 0.01g Resolution: 16bit Stability: 0.005g |
| ▶ Gyroscope | X, Y, Z, 3-axis ±2000°/s | Resolution: 16bit Stability: 0.05°/s |
| ▶ Magnetometer | X, Y, Z, 3-axis ±2Gauss | 6.67nT/LSB |
| ▶ Angle/ Inclinometer | X, Y, Z, 3-axis X, Z-axis: ±180° Y ±90° (Y-axis 90° is singular point) |
Accuracy:X, Y-axis: 0.05° Z-axis: 1°(after magnetic calibration) |
Accelerometer Parameters
| Parameter | Condition | Typical Value |
|---|---|---|
| Range | ±16g | |
| Resolution | 0.0005(g/LSB) | |
| RMS noise | Bandwidth = 100Hz | 0.75~1mg-rms |
| Static zero drift | Placed horizontally | ±20~40mg |
| Temperature drift | -40°C ~ +85°C | ±0.15mg/°C |
| Bandwidth | 5~256Hz |
Gyro Parameters
| Parameter | Condition | Typical Value |
|---|---|---|
| Range | ±2000°/s | |
| Resolution | ±2000°/s | 0.061(°/s)/(LSB) |
| RMS noise | Bandwidth = 100Hz | 0.028~0.07(°/s)-rms |
| Static zero drift | Placed horizontally | ±0.5~1°/s |
| Temperature drift | -40°C ~ +85°C | ±0.005~0.015 (°/s)/°C |
| Bandwidth | 5~256Hz |
Magnetometer parameters
| Parameter | Condition | Typical Value |
|---|---|---|
| Range | ±2Gauss | |
| Resolution | ±2Gauss | 6.67nT/LSB |
Pitch and roll angle parameters
| Parameter | Condition | Typical Value |
|---|---|---|
| Range | XY:±180°; Y:±90° | |
| Inclination accuracy | 0.2° | |
| Resolution | Placed horizontally | 0.0055° |
| Temperature drift | -40°C ~ +85°C | ±0.5~1° |
Heading Angle Parameter
| Parameter | Condition | Typical Value |
|---|---|---|
| Range | Z:±180° | |
| Heading accuracy | 9-axis algorithm, magnetic field calibration, dynamic/static | 1° (without interference from magnetic field) |
| 6-axis algorithm, static | 0.5° (Dynamic integral cumulative error exists) | |
| Resolution | Placed horizontally | 0.0055° |
Note [1]: Before use, please perform magnetic field calibration in the test environment to ensure that the sensor is familiar with the magnetic field in the environment. When calibrating, please keep away from magnetic interference.
Note [2]: In vibration environments, there will be cumulative errors, and the specific errors cannot be estimated. The actual test shall prevail.
Module Parameters
Basic Parameters
| Parameter | Condition | Minimum value | Default | Maximum value |
|---|---|---|---|---|
| Interface | UART | 4800bps | 115200bps | 230400bps |
| Hardware I2C | 400K | |||
| Analog I2C | 400K | |||
| Output content | 3-axis (acceleration, angular velocity, magnetic field, angle ) quaternion | |||
| Output rate | 0.2Hz | 10Hz | 200Hz | |
| Start Time | 1000ms | |||
| Operating temperature | -40°C | 85°C | ||
| Storage temperature | -40°C | 100°C | ||
| Shock proof | 20000g | |||
Electrical parameters
| Parameter | Condition | Min | Default | Max |
|---|---|---|---|---|
| Supply voltage | 3.3V | 5V | 5.5V | |
| Working current | Work (5V) | 11.5mA | ||
| Sleep (5V) | 10.05uA |
3.2 Size
Image of the WT901 sensor module, a small square board measuring 15mm x 15mm, with text labels 'WT901', 'SN:2019010410105', 'CE ISO9001'. Axes X, Y, and Z are indicated with arrows.
| Parameter | Specification | Tolerance | Comment |
|---|---|---|---|
| Length | 15 | ±0.1 | Unit: millimeter. |
| Width | 15 | ±0.1 | |
| Height | 2 | ±0.1 | |
| Weight | 1 | ±0.1 | Unit: gram |
3.3 Axial Direction
The coordinate system used for attitude angle settlement is the northeast sky coordinate system. Place the module in the positive direction, as shown in the figure below, direction right is the X-axis, the direction forward is the Y-axis, and direction upward is the Z-axis. Euler angle represents the rotation order of the coordinate system when the attitude is defined as Z-Y-X, that is, first turn around the Z-axis, then turn around the Y-axis, and then turn around the X-axis.
Diagram illustrating the coordinate system of the WT901 sensor. It shows the module with axes X, Y, and Z originating from its center, with arrows indicating positive directions. The Y-axis points forward, X-axis to the right, and Z-axis upwards.
4 Pin Definition
Top-down view of the WT901 sensor module, showing its PCB layout and pin assignments. Pins labeled D0, D2, VCC, VCC, RX, SCL, TX, SDA, GND, GND, D1, D3 are visible. The X, Y, and Z axes are also indicated.
| PIN | Function |
|---|---|
| ▶ VCC | 3.3-5V |
| ▶ RX | Serial data input, TTL interface |
| ▶ TX | Serial data output, TTL interface |
| ▶ GND | Ground |
| ▶ D0 | Analog input, Digital input and output, Set angle reference |
| ▶ D1 | Analog input, Digital input and output, PWM |
| ▶ D2 | Analog input, Digital input and output, Hardware reset, X+angle alarm output |
| ▶ D3 | Analog input, Digital input and output, Angle alarm output, X-angle alarm output |
| ▶ SDA | I2C signal line, Y-angle alarm output |
| ▶ SCL | I2C clock line, Y+angle alarm output |
5 Communication Protocol
Level: TTL level
Baud rate: 4800, 9600 (default), 19200, 38400, 57600, 115200, 230400, stop bit and parity.
Link to WT901 Protocol.
