9DOF 2 Click is a compact add-on board for applications which require lowest power motion tracking and magnetometer functionality. This board features the ICM-20948 a 9-axis MotionTracking™ sensor from TDK Invensense, which consist of two sensors combined into one package for universal 9DOF solution. In this package we have 3-axis gyroscope, a 3-axis accelerometer, 3-axis magnetometer, combined with Digital Motion Processor™ (DMP) and run-time calibration firmware. All this features makes 9DOF 2 Click excellent choice for manufacturers looking for a product to eliminate the costly and complex selection, qualification, and system level integration of discrete devices, guaranteeing optimal motion performance for consumers. Its also ideally suited for wearable sensors and IoT applications needed low power motion tracking device expandable with additional I2C sensors.

9DOF 2 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

9DOF 2 Click is based on the ICM-20948, a high performance, 9-axis MotionTracking™ IC from TDK Invensense. ICM-20948 also supports an auxiliary I2C interface to external sensors which offer a greater system flexibility. The output of each MEMS is processed and digitized by a separate sigma-delta 16-bit A/D converter (ADC). Three-axis gyroscope MEMS can be programmed to measure the rotation about each axis, in four different ranges of rotational speed (degrees per angle, DPS): ±250, ±500, ±1000, and ±2000. Three-axis accelerometer MEMS can be programmed to measure the acceleration along each axis, in four different acceleration ranges: ±2g, ±4g, ±8g, and ±16g. Three-axis magnetometer can do a full scale measurement of ±4900 µT.

Interrupt functionality is configured via the Interrupt Configuration register. Items that are configurable include the INT pin configuration, the interrupt latching and clearing method, and triggers for the interrupt. The interrupt is routed to the INT pin of the mikroBUS™.

A FIFO buffer helps to further reduce the processing load, offering temporary storage for the output data. The ICM-20948 contains a FIFO of size 512 bytes (FIFO size will vary depending on DMP feature-set) that is accessible via the Serial Interface. The FIFO configuration register determines which data is written into the FIFO. Possible choices include gyro data, accelerometer data, temperature readings, auxiliary sensor readings, and FSYNC input. Synchronization with an external digital signal is possible over the FSYNC pin. This pin is routed to the PWM pin of the mikroBUS™, labeled as SNC.

The embedded Digital Motion Processor (DMP) within the ICM-20948 offloads computation of motion processing algorithms from the host processor. The DMP acquires data from accelerometers, gyroscopes, and additional third party sensors such as magnetometers, and processes the data. The resulting data can be read from the FIFO. The DMP has access to the external pins, which can be used for generating interrupts.

ICM-20948 supports both SPI and I2C communication interfaces but only SPI interface is used on the 9DOF 2 Click. The voltage level conversion between ICM-20948 and 3.3V MCU is done by the TXB0108 bidirectional voltage level translator.

This Click board™ uses only SPI communication interface. It is designed to be operated only with 3.3V logic levels. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with logic levels of 5V.

• Interface: SPI
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V

• Schematic
• ICM-20948 Datasheet
• TXB0108 Datasheet
• mikroSDK
• GitHub