STMicroelectronics ISM6HG256X - An IMU That Can Track Large And Small Movements Simultaneously
Switchable accuracy ranges have long enabled IMUs to keep tabs on fast and slow motion. With the ISM6HG256X, STMicroelectronics introduces an IMU that can monitor both ranges simultaneously.
Selecting the correct measurement range is one of the classic tasks of metrology: The higher the maximum value of the range, the lower the resolution. With the ISM6HG256X, STMicroelectronics provides two ranges that can be activated simultaneously.
Specifically, the data sheet promises the following classes of channel:
• Dual 3-axis accelerometer channels
• Low-g channel ±2/±4/±8/±16 g full scale
• High-g channel ±32/±64/±128/±256 g full scale
• 3-axis gyroscope with extended selectable full scale
• ±250/±500/±1000/±2000/±4000 dps full scale
For data communication, the ISM6HG256X offers three configurations for maximum application flexibility. The host can contact the IMU using either I2C, I3C, or SPI. The IMU can connect to sub-sensors, thereby reducing bus contention as shown in the figure below.
Advanced AI Features Offload Sensor Data Analysis
Most MEMS acceleration sensors limit themselves to providing an accurate data stream for the application microcontroller. Especially in real-time or low-power scenarios, offloading sensor processing to the IMU yields significant advantages.
Thanks to STMicroelectronics's strong background in AI acceleration, the sensor core comes with a variety of automated interpretation features outlined in the figure.
That way, the host microcontroller can sleep or handle control tasks while the motion information is interpreted. An interrupt is raised only when a condition that requires monitoring by the main MCU occurs.
For example, a sensor fusion unit can combine all the information available to the IMU. It then provides a variety of ready-to-use vectors which can, for example, be used to determine the orientation of a gaming-related external peripheral:
• Game rotation vector, which provides a quaternion representing the attitude of the device
• Gravity vector, which provides a three-dimensional vector representing the direction of gravity
• Gyroscope bias, which provides a three-dimensional vector representing the gyroscope bias
Developers working on augmented health applications will be pleased to learn that a pedometer algorithm has been implemented. Its structure is shown in the figure, with additional information available in the data sheet.
## First-class ecosystem support available.
STMicroelectronics provides software libraries for the ISM6HG256X that simplify integration. In addition, two evaluation tools are available. Tool number one is the STEVAL-MKI248KA, which provides a standalone evaluation board that can be connected to a microcontroller or process computer application of choice.
Developers working closely with the STM32 ecosystem and leveraging modern STM MCUs, such as the STM32U535, should use the X-NUCLEO-IKS5A1. It comes in the Nucleo form factor, can mate with a variety of STM32 evaluation boards, and is supported by the ST Edge AI Suite, which includes tools such as MEMS-Studio and HSDatalog.
Conclusion
If an application needs a high-accuracy IMU with significant dynamic range and strong AI support, deploying the STMicroelectronics ISM6HG256X is an excellent choice. Thanks to its sensor-offloading capabilities, the main microcontroller can be used for other tasks without compromising motion-tracking accuracy.