To sense orientation using inertial measurements, an Inertial Measurement Unit (IMU) is required, and the more Degrees of Freedom (DoFs), the better. The ICM20948 from Invensense encapsulates 9 DoFs into a compact 3x3mm package, serving as a comprehensive solution for all your DoF needs. This tiny powerhouse doesn't just house one MEMS sensor die, as is common, but two sensor dies. It combines Invensense's MEMS 3-axis accelerometer and gyro with Asahi Kasei Microdevices Corporation's AK09916 3-axis magnetometer.
This chip is regarded as TDK's 'upgrade' to the widely-used (but now discontinued) MPU-9250; however, it is important to note that it is not precisely code-compatible.
The full range of nine measurement axes is provided by a team of 16-bit Analog to Digital Converters, which meticulously convert the raw analog signals from the MEMS sensors into digital readings accessible through I2C or SPI interfaces. Each sensor possesses the high-quality specifications one would anticipate from such devices. For more details, refer to the datasheet:
• 3-Axis Gyroscope with Programmable FSR of ±250 dps, ±500 dps, ±1000 dps, and ±2000 dps
• 3-Axis Accelerometer with Programmable FSR of ±2g, ±4g, ±8g, and ±16g
• 3-Axis Compass with a wide range to ±4900 µT
Now you have a versatile and efficient array of sensors at your disposal, poised to steer your project towards the right path!
Like any high-performance device, the ICM20948 has specific requirements for operation. Unlike the pick-and-place machines designed to handle these sensors, it's not easy for us to manually integrate such a small component into our circuits. Additionally, the ICM20948 operates on 1.8V, which, while increasingly common among device manufacturers, is not widely used by hobbyists, learners, and for prototyping. Bearing this in mind, we have mounted the ICM20948 on a breakout board equipped with a 1.8V voltage regulator and level-shifting circuitry, making it compatible with 3.3V devices like the Feather M4 or Raspberry Pi, as well as 5V devices like the Arduino Uno.
The Adafruit TDK InvenSense ICM-20948 9-DoF IMU breakout simplifies connections by making the ICM20948 pins available on standard 0.100”/ 2.54mm pitch headers for breadboard use. For those who prefer not to solder, the Stemma QT form factor breakout includes Stemma QT connectors, which are compatible with and inspired by SparkFun Qwiic connectors. These connectors allow you to easily plug in the sensor and start your project, and they also support daisy-chaining multiple sensors together.