WitMotion HWT901B Accelerometer With Air Pressure – MPU9250 9-Axis Gyro/Angle/Compass AHRS IMU, 0.1° Pitch/Roll, 200Hz, RS232/RS485/TTL, IP68

Overview

The WitMotion HWT901B is an industrial-grade attitude & heading reference inclinometer that integrates high-precision 3-axis gyroscope, 3-axis accelerometer, and 3-axis magnetometer with magnetic-field recovery. A high-performance 32-bit MCU runs an in-module attitude solver with dynamic fusion + Kalman filtering, delivering stable, low-noise angle data. Typical pitch/roll accuracy is 0.1° (static); long-term heading stability is achieved by 9-axis fusion with magnetometer compensation (requires calibration). The rugged aluminum enclosure offers IP68 protection , wide 5–36 V supply, and robust EMC immunity for harsh, long-duty industrial use.

Key Features

• 9-axis AHRS with Kalman filtering and advanced digital filtering to suppress noise and drift

• Magnetometer compensation with military-grade PNI RM3100 geomagnetic sensor for high repeatability and automatic recovery from magnetic disturbance

• Selectable output content: time, 3-axis acceleration, 3-axis angular velocity, 3-axis angle, 3-axis magnetic field

• Adjustable rates: baud 4800–230400 bps; output 0.2–200 Hz (max 200 Hz)

• Interfaces: TTL / RS-232 / RS-485; CAN option shown in model list

• Rugged build: aluminum shell, IP68 sealing, strong EMI resistance

• Free PC software (real-time curves, logging/export, calibration, configurable bandwidth and content) and Android app for configuration and data viewing

• Typical uses: construction machinery, smart farming, tower cranes, automation lines

Specifications

Accelerometer parameters

Parameters	Condition	Typical value
Measuring range		±16g
Resolution ratio	±16g	0.0005(g/LSB)
RMS noise	Bandwidth=100Hz	0.75~1mg-rms
Static zero drift	Place horizontally	±20~40mg
Temperature drift	-40°C ~ +85°C	±0.15mg/℃
Bandwidth		5~256Hz

Gyroscope parameters

Parameters	Condition	Typical value
Measuring range		±2000°/s
Resolution ratio	±2000°/s	0.061(°/s)/(LSB)
RMS noise	Bandwidth=100Hz	0.028~0.07(°/s)-rms
Static zero drift	Place horizontally	±0.5~1°/s
Temperature drift	-40°C ~ +85°C	±0.005~0.015 (°/s)/℃
Bandwidth		5~256Hz

 

Magnetometer parameters

Parameters	Condition	Typical value
Measuring range		±2Gauss
Resolution ratio	±2Gauss	8.333nT/LSB

Pitch and roll angle parameters

Parameters	Condition	Typical value
Measuring range		X:±180°
		Y:±90°
Inclination accuracy		0.1°
Resolution ratio	Place horizontally	0.0055°
Temperature drift	-40°C ~ +85°C	±0.5~1°

 

Heading angle parameter

Parameters	Condition	Typical value
Measuring range		Z:±180°
Heading accuracy	9-axis algorithm, magnetic field calibration, dynamic/static	1°（Without interference from magnetic fields）【1】
	6-axis algorithm, static	0.5°（Dynamic integral cumulative error exists） 【2】
Resolution ratio	Place horizontally	0.0055°

Note:【1】Please perform magnetic field calibration in the testing environment before use to ensure that the sensor is familiar with the magnetic field in the environment. During calibration, please stay away from magnetic interference. 

【2】In some vibration environments, there will be cumulative errors. The specific errors cannot be estimated and are subject to actual testing.

Applications

Construction boom/vehicle leveling, agricultural implements and auto-steer logging, tower-crane sway/angle monitoring, and factory automation attitude/tilt feedback.

Details

Industrial rugged inclinometer, 0.05deg XY axis accuracy, 3-axis acceleration, gyro, angle, magnetic field, quaternion.

WitMotion HWT901B is a high-performance AHRS featuring MEMS sensor, magnetometer, 32-bit MCU, IP67 protection, and aluminum casing. It provides drift-free roll, pitch, yaw data, stable measurements, magnetic compensation, fast processing, waterproofing, and corrosion resistance.

WitMotion HWT901B includes a military-grade RM3100 magnetometer, core fusion algorithm, and certifications like CE, ISO-9001, IP-rating, and calibration report.

WitMotion Algorithm x Kalman Filter. Derived from Aerospace Satellite Attitude Determination Algorithm, integrated with Kalman filtering and motion dynamic fusion. Angle accuracy: X, Y-axis 0.05° (static), 0.1° (dynamic); Z-axis 1° (calibrated).

High-speed 32-bit processor, 168MHz, low-power, fast data processing

IP67 waterproof accelerometer with aluminum casing, durable for harsh environments.

Free & genuinely useful PC software for WitMotion HWT901B accelerometer. Easy setup: download tutorial, install CH340 driver, connect via USB, run MiniIMU.exe. Real-time data display includes acceleration, angle, GPS, and more on laptop interface.

WitMotion HWT901B accelerometer offers configurable settings like calibration, output frequency, and data content. It provides real-time motion data visualization with angle, acceleration, and magnetic field measurements for accurate, convenient data collection.

WitMotion HWT901B accelerometer offers data storage, real-time readings, timestamped logs, and compass visualization. Data displays on software, saves as TXT, and imports to Excel for analysis.

3D demo of sensor motion state visualization with car, helmet, cube, and drone models.

HWT901B supports Android serial connection for efficient data viewing. App displays angle, magnetic data, and temperature. USB-C adapter not included.

Android app for WitMotion sensor configuration, data recording, and export. Features include module selection, calibration, real-time data display, and TXT format export. Supports 3-axis, 6-axis, 9-axis, BLE 5.0, and WT901-WIFI series.

Development Kits include manual, datasheet, Windows software, CH340 & CP2102 drivers, sample code for STM32, Arduino, 51, C++, and Matlab. Features PDFs, driver folder, demo videos, and Android app.

HWT901B is a 3D sensor with MEMS accelerometer, gyroscope, and magnetometer. It supports multiple interfaces, offers high accuracy, and measures acceleration, angle, and magnetic field. Dimensions: 55×36.8×24mm.

The WitMotion HWT901B Accelerometer has dimensions of 55mm x 47.9mm x 36.8mm with a 4.2mm mounting hole. It features TTL and RS232 pin configurations: red (VCC, 5V or 5-36V), yellow (TX), green (RX), and black (GND). Connection diagrams show how to link the sensor to a USB module and power source. The RS232 interface accepts 5-36V power input, with labeled pins for power, TXD, RXD, and ground. A laptop is included in the setup for data monitoring.

Pin definitions for RS485, CAN, and MCU interfaces are detailed. RS485 uses red (VCC 5–36V), yellow (A), green (B), and black (GND). CAN uses red (VCC 5–24V), yellow (CANH), green (CANL), and black (GND). The MCU section shows VCC, TX, RX, and GND connections to a sensor. Color-coded wires link power, data, and ground. Each interface lists voltage ranges and signal functions for integration with sensors and microcontrollers.

WitMotion HWT901B Accelerometer with cable, labeled VCC, RX, TX, GND and color-coded wires.