WitMotion WT931 9-Axis Attitude Sensor (Accelerometer + Gyro + Magnetometer) — UART-TTL / I²C IMU for Arduino & STM32

Overview

WT931 is a miniature 9-axis attitude sensor/IMU that integrates a 3-axis accelerometer, 3-axis gyroscope, and 3-axis geomagnetic (electronic compass). With an onboard MCU and Kalman filtering, it outputs roll/pitch/yaw angles, quaternion, acceleration, angular velocity, magnetic field, time-stamp and more. The module features a 12 mm × 12 mm × 2 mm package, 3.3 V supply, and supports UART-TTL and I²C (up to 400 kHz). Default and maximum output rates shown in the images are 0.1–500 Hz (500 Hz default), making the WT931 ideal for robotics, motion capture, VR, UAVs, agriculture and industrial devices. It works with Arduino, STM32/51 MCUs, Windows C/C#, and MATLAB; free PC software enables data recording, curve display, dashboard/3D view, and calibration.
Note: All specs below are taken from the provided product images.

---

Key Features

• 9-Axis IMU + Attitude Solver: Acc + Gyro + Mag with real-time roll/pitch/yaw and quaternion.

• Kalman Filtering Technique: Fuses multi-sensor data for high precision and high stability attitude output.

• High-rate, small package: 0.1–500 Hz selectable output (default 500 Hz), ultra-compact 12×12×2 mm.

• Low power: < 25 mA at 3.3 V.

• Interfaces: UART-TTL (2,400–921,600 bps) and I²C (up to 400 kHz).

• PC & Android tools: PC software (record, curves, dashboard, config, calibration) and Android app via USB-OTG/Type-C with evaluation board.

• Developer-friendly: Sample projects for STM32, Arduino, 51, Windows C/C#, MATLAB.

---

Core Parameters

• Supply Voltage: 3.3 V

• Current: < 25 mA

• Size / Weight: 12 mm × 12 mm × 2 mm, ≈ 0.34 g

• Pad spacing: up/down 1.27 mm; left/right 12 mm

• Measured Quantities: Acc (X/Y/Z), Gyro (X/Y/Z), Angle (X/Y/Z), Magnetic field (X/Y/Z), Quaternion, Time

• Ranges:

  • Acceleration: ±2/4/8/16 g

  • Angular velocity: ±250/500/1000/2000 °/s

  • Angle: X/Z ±180°, Y ±90°

• Stability: Acc 0.01 g; Angular speed 0.05 °/s

• Angle accuracy (after calibration, no magnetic interference):

  • X/Y: static 0.05°, dynamic 0.1°

  • Z: 1°

• Output Rate: 0.1–500 Hz (default 500 Hz)

• Baud Rates (UART-TTL): 2,400 … 921,600 bps

• I²C: supports high-rate 400 kHz

• Data Output: time, acceleration, angular velocity, angle, magnetic field, quaternion

---

Pin Definition

1 GND — Ground
2 SWCLK — Download clock
3 SWDIO — Download data transmission
4 SCL — I²C clock
5 SDA — I²C data
6 RX — Serial data input (TTL)
7 TX — Serial data output (TTL)
8 VCC — Power supply 3.3 V
9 D0 — Expansion port 0
10 D1 — Expansion port 1
11 D2 — Expansion port 2
12 D3 — Expansion port 3
13 D4 — Expansion port 4
14 D5 — Expansion port 5

---

Connectivity & Tools

• To PC: USB-to-TTL adapter (3.3 V), TX↔RX, RX↔TX, GND↔GND; configure, record, calibrate via PC software (Windows XP/7/8/10).

• To Android: Evaluation board + OTG/Type-C adapter; real-time data display/record.

• To MCU: 3.3 V logic; connect via UART-TTL or I²C.

---

Typical Applications

• Motion capture, VR/AR head tracking

• Aerospace & navigation, robotics balance, UAV/UGV attitude

• Agricultural & industrial equipment tilt/heading measurement

• Inclinometer use cases requiring compact, high-rate attitude data

Details

9-axis attitude sensor with no-drift inclinometer, small package, 500Hz high rate, high frequency. Uses Kalman filtering for aerospace and navigation applications.

High-precision, high-stability 9-axis sensor with motion capture, VR, and industrial applications. Features acceleration, angular velocity, angle, geomagnetic data, UART output, and quaternion support.

WitMotion WT931 9-axis sensor integrates gyroscopes, accelerometer, and microprocessor with Kalman filter for precise attitude measurement. Features include 500Hz data rate, 4-layer PCB, PLCC-28 package, and voltage stabilization from 3.3V to 5V.

WitMotion WT931 has 14 pins for power, ground, serial, I2C, and expansion. It supports data transmission, clock signals, and multiple GPIOs for flexible connectivity and control.

WitMotion WT931 9-axis attitude sensor, 0.34g, 3.3V, <25mA current, 12×12×2mm size. Measures acceleration, angle, gyro, magnetic field in X/Y/Z axes. Supports UART/TTL, up to 921600bps, outputs quaternion data.

PC software for parameter setting, calibration, data recording, 3D module, curve display, dashboard, config, Windows XP 7 8 10.

Android APP connects to phone via USB serial and OTG/Type-C. Displays data like X, Y, Z, temperature. Features record function and evaluation board connection.

WitMotion WT931 9-Axis Attitude Sensor connects via USB to computer or Android app, supports MCU integration. Features high performance, stability, and precision with 3.3V power, UART communication, and SWD/SPI interfaces.

WitMotion WT931 9-Axis Sensor, top and bottom views, size comparison on finger.

Quality certifications include ISO standards, software copyrights, SGS approval, and showcase advanced manufacturing with automated production and PCB inspection.