3.4.4 ICM-20689 6-Axis Inertial Sensor
The ICM-20689 is a 6-axis inertial sensor consisting of a 3-axis gyroscope and a 3-axis accelerometer. The sensor detects acceleration
and angular rate in and around the X-, Y-, and Z-axes with integrated 16-bit ADCs and programmable digital filters.
On xG24 Dev Kit, the ICM-20689 is connected through a switch. The switch must be enabled by setting PC09 high before it can be
used by the application. This enables power to the ICM-20689 and connects the SPI lines used for the sensor to the EFR32MG24 SPI
bus. The application code should always drive the PC09 signal either high or low to prevent it from floating. Note the presence of the
external pull-up resistor on the interrupt line as this can cause back powering if not handled correctly in software. The SPI CS line is
also exported on the breakout pads, so simultaneous SPI operation on the breakout pads and IMU is not possible unless an alternative
pin is used for SPI CS on the breakout pads. The figure below shows how the ICM-20689 is connected to the EFR32MG24.
VMCU
EFR32MG24
PC01
PC03
PC09
SPI_SCLK
SPI_COPI
SENSOR_ENABLE
IMU_SPI_SCLK
IMU_SPI_COPI
0: Sensor is not powered
1: Sensor is powered
ICM-20689
6-axis Intertial
Sensor
SPI_CIPO
PC02
IMU_SPI_CIPO
IMU_SPI_CS
VDD_SENSOR
IMU_INT
PB01 (EM4WU3)
SPI_CS
PA07
Figure 3.7. ICM-20689 6-Axis Inertial Sensor
The inertial sensor is located close to the geometrical center of the board. The coordinate system and rotation of the sensor follows the
right-hand rule, and the spatial orientation of the board is shown in the figure below.
Figure 3.8. xG24 Dev Kit Spatial Orientation
UG524: xG24 Dev Kit User's Guide
Hardware
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