Gravity: 6DOF IMU Sensor for Motion & Gesture Detection (I2C / UART, Plug & Play)

The Gravity BMI323 6DOF IMU Sensor is a plug-and-play motion sensing module built around the Bosch BMI323. It combines a 3-axis accelerometer and a 3-axis gyroscope to measure linear acceleration, angular velocity, tilt, vibration and motion changes. Built-in step, tap, tilt, free-fall and activity events reduce basic host-side processing, while I2C/UART, 3.3–5 V compatibility, selectable addresses and Gravity wiring make it suitable for fast Arduino, ESP32 and Raspberry Pi prototyping.

Choose this Gravity version when the goal is to connect quickly, view data before writing application code and use one integrated DFRobot library. For compact, low-power product integration and direct access to the original BMI323 interface, choose the Fermion BMI323 6DOF version instead.

Up to 6400 Hz 6-Axis Motion Sensing

The Bosch BMI323 combines a 16-bit 3-axis accelerometer and 16-bit 3-axis gyroscope for high-rate motion measurement. The accelerometer offers ±2 g, ±4 g, ±8 g and ±16 g ranges, while the gyroscope covers ±125 °/s to ±2000 °/s. Output data rates up to 6400 Hz support both slow tilt monitoring and fast rotation, vibration or gesture capture.

Hardware Motion Intelligence Beyond Raw Data

BMI323 can detect step counting, single or multiple taps, tilt, free fall and activity states directly in hardware. Two programmable interrupt pins can notify the host when an event occurs, allowing Arduino or ESP32 projects to react to motion without continuously processing every raw sample.

Figure: Reading Accumulated Step Count via I2C

FIFO and Multiple Power Modes for Stable Data Collection

A 2048-byte FIFO buffers motion samples when the host controller is busy, helping maintain continuous data collection at higher sampling rates. Sleep, Low Power, Normal and High Performance modes allow developers to select the response speed and power profile required by the application.

Gravity Integration Makes BMI323 IMU Easier to Use

The Gravity implementation adds an onboard MCU, one integrated DFRobot library, I2C/UART, a PH2.0-4P connector, 3.3–5 V operation and four selectable module addresses (0x4A–0x4D). Gravity GUI software lets users inspect live motion data before completing the application, reducing wiring, protocol setup and initial debugging.