Name: Gravity: BMI323+BMM350 9DOF IMU Sensor (I2C / UART, Plug & Play)
Brand: DFRobot
SKU: SEN0694
Price: 15.9 USD
Availability: InStock

Introduction

Gravity: BMI323 + BMM350 9 DOF IMU Sensor combines a 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer in one compact motion sensing module. Built around Bosch BMI323 and BMM350, it provides acceleration, angular velocity, and magnetic field data for heading-aware motion sensing, electronic compass prototypes, wearable devices, robotics experiments, and embedded orientation projects.

Compared with a basic 6-axis IMU, this 9 DOF module adds magnetometer data for direction-related sensing and 9-axis attitude evaluation. Gravity wiring, I2C/UART communication, selectable I2C addresses, programmable interrupt pins, and GUI visualization help reduce early-stage bring-up and debugging work.

Why It Matters: When 6-Axis Motion Data Is Not Enough

A 6-axis IMU can measure acceleration and rotation, but gyroscope-based orientation estimates may drift over time. Projects that need heading reference, electronic compass functions, or direction-aware interaction usually require magnetic field data.

By adding the BMM350 3-axis magnetometer, this module provides an additional magnetic reference for 9-axis motion evaluation, making it more suitable for heading-aware robotics, wearable motion devices, handheld controllers, and orientation tracking prototypes.

Developer Pro-Tips

Magnetometer Placement: Keep the module away from strong magnets, motors, speakers, steel structures, and high-current wiring. Magnetometer calibration should be performed after final installation.

Accelerometer Range Selection: Use ±2g for slow tilt and orientation changes, ±4g or ±8g for general wearable and handheld motion, and ±16g for impact or fast movement detection.

Gyroscope Range Selection: Use lower gyroscope ranges for slow rotation and higher sensitivity. Use ±1000°/s or ±2000°/s for fast gestures or rapid device movement.

ODR Selection: High ODR is useful for fast motion capture and rapid gesture detection. Lower ODR settings are better for battery-powered wearables and slow orientation tracking.

Interrupt-Based Design: Use programmable interrupt pins for tap, tilt, free-fall, activity, or motion events to reduce continuous polling in low-power embedded systems.

BMI323 Multi-DOF IMU Sensor Series

From 6-axis motion sensing to 10-axis altitude-aware orientation.

6DOF Motion: Acceleration + Gyroscope. For tilt detection, gesture input, vibration sensing, rotation tracking, and basic motion feedback.

9DOF Heading: Motion + Magnetometer. For projects that need motion sensing with magnetic heading reference, orientation correction, or electronic compass functionality.

10DOF Altitude: Motion + Heading + Barometer. For applications that require acceleration, rotation, magnetic heading, and barometric pressure or altitude-related data.

Choose by Form Factor

Gravity: Easier wiring, I2C/UART, rapid prototyping

Fermion: Compact size, I2C, embedded integration

Features

9 DOF Motion Sensing: Integrates a 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer for acceleration, angular velocity, and magnetic field measurement.

BMI323 + BMM350 Sensor Combination: Uses Bosch BMI323 for 6-axis inertial sensing and BMM350 for 3-axis magnetic field sensing, enabling heading-aware motion data evaluation.

Built-In Motion Event Detection: Supports step counting, tap detection, tilt detection, free-fall detection, and activity recognition, reducing the need to build every basic motion event from raw sensor data.

I2C/UART for Flexible Development: Supports both I2C and UART communication for Arduino, ESP32, Raspberry Pi, and other embedded platforms.

4 Selectable I2C Addresses: Supports 0x4A, 0x4B, 0x4C, and 0x4D to reduce conflicts in multi-sensor I2C systems.

3 Programmable Interrupt Pins: Allows motion events or sensor conditions to trigger host-side responses without continuous polling.

Applications

Electronic Compass and Heading Reference

Robotics Orientation Feedback

Wearable Motion Devices

Gesture-Controlled Handheld Devices

Specification

Basic Parameters

Operating Voltage: DC 3.3–5 V

Operating Current: 3.42 mA

Communication Interface: I²C / UART

Connector Type: PH2.0-4P (Gravity pinout) / 2.54 mm pin header holes

I²C Addresses: 0x4A (default) / 0x4B / 0x4C / 0x4D

Programmable Interrupt Pins: ×3

Accelerometer Parameters

Measurement Ranges: ±2 g, ±4 g, ±8 g, ±16 g

ADC Resolution: 16-bit

Sensitivity
±2 g range: 16384 LSB/g
±4 g range: 8192 LSB/g
±8 g range: 4096 LSB/g
±16 g range: 2048 LSB/g

Sensitivity Error: ±0.5%

Zero-g Offset: ±50 mg

Output Data Rate (ODR)
High Performance / Normal mode: 12.5 Hz ~ 6400 Hz
Low Power mode: 0.78125 Hz ~ 400 Hz

Gyroscope Parameters

Angular Rate Ranges: ±125, ±250, ±500, ±1000, ±2000 °/s

ADC Resolution: 16-bit

Sensitivity
±2000 °/s range: 16.384 LSB/(°/s)
±1000 °/s range: 32.768 LSB/(°/s)
±500 °/s range: 65.536 LSB/(°/s)
±250 °/s range: 131.072 LSB/(°/s)

Sensitivity Error: ±3% (without self-calibration), ±0.7% (after self-calibration)

Zero-Rate Offset: ±1 °/s

Output Data Rate (ODR)
High Performance / Normal mode: 12.5 Hz ~ 6400 Hz
Low Power mode: 0.78125 Hz ~ 400 Hz
Magnetometer Parameters

Operating Modes: Normal periodic measurement, triggered forced measurement, low-power sleep standby

Measurement Range: ±2000 µT

Magnetic Field Resolution: approx. 0.1 µT

Zero-Field Offset Drift: ±2 µT (-40 °C ~ +85 °C, after calibration)

X/Y-Axis Gain Error: ±1% (25 °C, after compensation)

Z-Axis Gain Error: ±3% (25 °C, after compensation)

Sensitivity Temperature Drift: ±0.010 %/K

Offset Temperature Error: ±200 nT/K

Normal Mode Output Data Rate: 400/200/100/50/25/12.5/6.25/3.125/1.5625 Hz, typical deviation ±2%

Forced Mode Maximum Trigger Frequency: 200 Hz

X/Y-Axis Output Noise: 190 nTrms

Z-Axis Output Noise: 450 nTrms

Physical Dimensions

PCB Size: 32 mm × 27 mm

Mounting Hole Spacing: 20 mm

Mounting Hole Diameter: 3 mm

Shipping List

Gravity: High Precision 9 DOF IMU Sensor ×1

Gravity 4P Sensor Cable ×1

2.54 mm Black Single Row Pin Header – 10-Pin ×1

Documents

Product Wiki

Certifications

CE CE
RoHS RoHS

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