TS-7180 IMU

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Revision as of 09:06, 14 May 2020 by Mark (talk | contribs)

The TS-7180 has an optional Invensense MPU-9250 motion-tracking device. This device provides:

  • 3-axis Gyroscope
  • 3-axis Accelerometer
  • 3-axis Magnetometer
  • Temperature sensor

The MPU-9250 is connected to the CPU via I2C. The device is actually two chips in one: The first contains the gyroscope, accelerometer, and temperature sensor. The second contains the magnetometer. Because there are two chips, there are two I2C chip addresses: 0x69, and 0x0C. It order to use the magnetometer, it is first necessary to run the following command:

echo ak8975 0x0c > /sys/bus/i2c/devices/i2c-5/new_device


User interface to the device is done through the sys filesystem.

The gyroscope, accelerometer, and temperature readings are available at: /sys/bus/iio/devices/iio:device1

The gyroscope measures angular velocity in three axes. The raw values are available at:

/sys/bus/iio/devices/iio:device1/in_anglvel_x_raw

/sys/bus/iio/devices/iio:device1/in_anglvel_y_raw

/sys/bus/iio/devices/iio:device1/in_anglvel_z_raw


The accelerometer measures acceleration along three axes. The raw values are available at:

/sys/bus/iio/devices/iio:device1/in_accel_x_raw

/sys/bus/iio/devices/iio:device1/in_accel_y_raw

/sys/bus/iio/devices/iio:device1/in_accel_z_raw


The magnetometer readings are available at: /sys/bus/iio/devices/iio:device2

The magnetometer measures magnetic field strength in three axes. The raw values are available at:

/sys/bus/iio/devices/iio:device2/in_magn_x_raw

/sys/bus/iio/devices/iio:device2/in_magn_y_raw

/sys/bus/iio/devices/iio:device2/in_magn_z_raw