IMU - Inertial Measurement Unit

Description

Inertial Measurement Unit driver.


IMU example code

Basic example for looping measurement of orientation data: 

#include "sl_imu.h"

int main( void )
{

  ...

  int16_t o_vec[3];

  sl_imu_init();

  // Configure sample rate
  sl_imu_configure(10);

  // Recalibrate gyro
  sl_imu_calibrate_gyro();

  while (true) {

    sl_imu_update();

    while (!sl_imu_is_data_ready()) {
      // wait
    }

    sl_imu_get_orientation(o_vec);

    ...

  }
}

Modules

Direction Cosine Matrix
Unit DCM matrix related routines.
IMU Fusion
IMU fusion driver.
Vector and Matrix Math
Inertial measurement unit fusion driver math routines.

Functions

sl_status_t sl_imu_init (void)
Initialize and calibrate the IMU chip.
sl_status_t sl_imu_deinit (void)
De-initialize the IMU chip.
uint8_t sl_imu_get_state (void)
Return IMU state.
void sl_imu_update (void)
Get a new set of data from the accel and gyro sensor and updates the fusion calculation.
void sl_imu_reset (void)
Reset the fusion calculation.
void sl_imu_get_acceleration (int16_t avec[3])
Retrieve the processed acceleration data.
void sl_imu_get_orientation (int16_t ovec[3])
Retrieve the processed orientation data.
void sl_imu_get_gyro (int16_t gvec[3])
Retrieve the processed gyroscope data.
sl_status_t sl_imu_calibrate_gyro (void)
Perform gyroscope calibration to cancel gyro bias.
void sl_imu_get_gyro_correction_angles (float acorr[3])
Retrieve the processed gyroscope correction angles.
void sl_imu_configure (float sampleRate)
Configure the IMU.
bool sl_imu_is_data_ready (void)
Check if new accel/gyro data is available for read.
void sl_imu_get_acceleration_raw_data (float avec[3])
Retrieve the raw acceleration data from the IMU.
void sl_imu_get_gyro_raw_data (float gvec[3])
Retrieve the raw gyroscope data from the IMU.

State Definitions

#define IMU_STATE_DISABLED 0x00
The IMU is disabled

#define IMU_STATE_READY 0x01
The IMU is fully configured and ready to take measurements

#define IMU_STATE_INITIALIZING 0x02
The IMU is being initialized

#define IMU_STATE_CALIBRATING 0x03
The IMU is being calibrated

Function Documentation

◆ sl_imu_init()

sl_status_t sl_imu_init ( void )

Initialize and calibrate the IMU chip.

Returns
Returns zero on OK, non-zero otherwise

◆ sl_imu_deinit()

sl_status_t sl_imu_deinit ( void )

De-initialize the IMU chip.

Returns
Returns zero on OK, non-zero otherwise

◆ sl_imu_get_state()

uint8_t sl_imu_get_state ( void )

Return IMU state.

Returns
IMU state

◆ sl_imu_update()

void sl_imu_update ( void )

Get a new set of data from the accel and gyro sensor and updates the fusion calculation.

◆ sl_imu_reset()

void sl_imu_reset ( void )

Reset the fusion calculation.

◆ sl_imu_get_acceleration()

void sl_imu_get_acceleration ( int16_t avec[3] )

Retrieve the processed acceleration data.

Parameters
[out] avec Three dimensional acceleration vector

◆ sl_imu_get_orientation()

void sl_imu_get_orientation ( int16_t ovec[3] )

Retrieve the processed orientation data.

Parameters
[out] ovec Three dimensional orientation vector

◆ sl_imu_get_gyro()

void sl_imu_get_gyro ( int16_t gvec[3] )

Retrieve the processed gyroscope data.

Parameters
[out] gvec Three dimensional gyro vector

◆ sl_imu_calibrate_gyro()

sl_status_t sl_imu_calibrate_gyro ( void )

Perform gyroscope calibration to cancel gyro bias.

Return values
SL_STATUS_OK

◆ sl_imu_get_gyro_correction_angles()

void sl_imu_get_gyro_correction_angles ( float acorr[3] )

Retrieve the processed gyroscope correction angles.

Parameters
[out] acorr Three dimensional gyro correction angle vector

◆ sl_imu_configure()

void sl_imu_configure ( float sampleRate )

Configure the IMU.

Parameters
[in] sampleRate The desired sample rate of the acceleration and gyro sensor

◆ sl_imu_is_data_ready()

bool sl_imu_is_data_ready ( void )

Check if new accel/gyro data is available for read.

Returns
True if the measurement data is ready, false otherwise

◆ sl_imu_get_acceleration_raw_data()

void sl_imu_get_acceleration_raw_data ( float avec[3] )

Retrieve the raw acceleration data from the IMU.

Parameters
[out] avec Three dimensional raw acceleration vector

◆ sl_imu_get_gyro_raw_data()

void sl_imu_get_gyro_raw_data ( float gvec[3] )

Retrieve the raw gyroscope data from the IMU.

Parameters
[out] gvec Three dimensional raw gyro vector

Macro Definition Documentation

◆ IMU_STATE_DISABLED

#define IMU_STATE_DISABLED   0x00

The IMU is disabled

◆ IMU_STATE_READY

#define IMU_STATE_READY   0x01

The IMU is fully configured and ready to take measurements

◆ IMU_STATE_INITIALIZING

#define IMU_STATE_INITIALIZING   0x02

The IMU is being initialized

◆ IMU_STATE_CALIBRATING

#define IMU_STATE_CALIBRATING   0x03

The IMU is being calibrated