Overview
WitMotion WT31N Inclinometer is a miniature MEMS module that measures 3-axis acceleration (X/Y/Z) and computes dual-axis angle (roll & pitch on X/Y) with an onboard Kalman filter and 8-bit MCU. It outputs time, acceleration, and angle over UART (TTL) at up to 100 Hz. Designed for compact embedded projects, it supports 3.3–5 V systems and connects easily to PCs (USB-TTL) or Android phones (OTG + USB-TTL).
Note: the WT31 reports X/Y angles only; no Z-axis angle (no gyroscope on the module).
Key Features
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Acceleration: X/Y/Z axes
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Angles: X (roll), Y (pitch)
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Static angle accuracy: ±0.1° (X/Y)
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Filter/solver: Kalman filter, onboard angle calculation (AHRS-style output for X/Y)
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Output interface: UART (TTL), 115200 baud (TX↔RX cross)
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Update rate: 100 Hz
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Supply & draw: 3.3–5 V, <10 mA
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PC software: data recording, dashboard/3D module, curve display (Windows XP/7/8/10)
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Android app: configuration, calibration, live data & recording (via OTG + USB-TTL)
Specifications
| Item | Value |
|---|---|
| Product name | WT31 Inclinometer |
| Brand | WitMotion |
| IC | STM8 + LIS3DH |
| Supply voltage | 3.3 V – 5 V |
| Current | <10 mA |
| Output data | Time, Acceleration, Angle |
| Axes | ACC: X/Y/Z; Angle: X/Y (roll/pitch) |
| Acceleration range | ±16 g |
| Angle range | X: ±90°, Y: ±90° |
| Acceleration resolution | 0.0005 g |
| Static angle accuracy | ±0.1° (X/Y) |
| Dynamic angle | Not applicable (no gyro) |
| Update rate | 100 Hz |
| Interface | UART (TTL) |
| Baud rate | 115200 |
| Size | 15.24 mm × 15.24 mm × 2 mm |
| Weight | ≈0.34 g |
| Note | No Z-axis angle because no gyroscope |
Dimensions (board)
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A = 15.24 mm, B = 15.24 mm, C = 2.54 mm, D = 12.7 mm, E = 2 mm (per drawing)
Pin Definition
| No. | Name | Function |
|---|---|---|
| 1 | D0 | — |
| 2 | VCC | 3.3–5 V |
| 3 | RX | UART-TTL Receiver |
| 4 | TX | UART-TTL Transmitter |
| 5 | GND | Ground |
| 6 | D1 | — |
| 7 | D2 | X+ alarm |
| 8 | VCC | 3.3–5 V (second pad) |
| 9 | S1 | Y+ alarm |
| 10 | S2 | Y- alarm |
| 11 | GND | Ground |
| 12 | D3 | X- alarm |
Connection tips
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MCU: VCC→VCC, TX→RX, RX→TX, GND→GND.
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PC: connect via USB-TTL adapter.
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Android: OTG + USB-TTL adapter.
Software & App Functions
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Data record and export
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3D module / dashboard visualization
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Real-time data curve display
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Config & calibration menus in app
Typical Applications
IoT tilt monitoring, UGV/robot leveling, mapping rigs, environmental/structural monitoring, energy equipment alignment, and building protection where compact accelerometer + inclinometer data and UART-TTL output are required.
Details

MEMS IMU for IoT, environmental monitoring, UGV, energy, mapping, and building protection. WT31 Inclinometer offers 0.1° accuracy, Kalman filter, UART output, and measures acceleration, angular velocity, and angle.

High precision inclinometer with Kalman filter and 8Bit MCU

PC software features: data record, 3D module, curve display, dashboard, configuration, compatible with Windows XP/7/8/10. Connection: VCC TX RX GND connected to USB-TTL +5V/3V3 RX TX GND; TX to RX, RX to TX.

Software displays real-time sensor data (acceleration, angle, magnetic fields). Requires OTG and USB-TTL for Android devices, with wiring details and interface layout for module setup and calibration.

WitMotion WT31N inclinometer app displays settings, real-time data, and logs. Connection diagram shows MCU interface with VCC, TXD, RXD, GND pins for serial communication.

WitMotion WT31 inclinometer, 0.34g, STM8+Lis3dh IC, 3.3V-5V, <10mA, 15.24×15.24×2mm. Outputs acceleration, angle data via UART (TTL) at 115200bps, 100Hz rate. No Z-axis angle due to no gyroscope.

Pin definition for WitMotion WT31N inclinometer, including dimensions and functions of 12 pins, with UART TTL interface and alarm signals.
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