Detailed Description

Inertial Measurement Unit driver.

Data Structures
struct	_IMU_SensorFusion
	Structure to store the sensor fusion data.

Typedefs
typedef struct _IMU_SensorFusion	IMU_SensorFusion
	Structure to store the sensor fusion data.

Functions
void	IMU_accelerationGet (int16_t avec[3])
	Retrieves the processed acceleration data.

void	IMU_clearDataReadyFlag (void)
	Clears the IMU data ready flag. In case of ver 0.3.0 and older of the PIC firmware the interrupt register also needs to be cleared.

void	IMU_config (float sampleRate)
	Configures the IMU.

void	IMU_dcmGetAngles (float dcm[3][3], float angle[3])
	Calculates the Euler angles (roll, pitch, yaw) from the DCM matrix.

void	IMU_dcmNormalize (float dcm[3][3])
	Normalizes the DCM matrix.

void	IMU_dcmReset (float dcm[3][3])
	Sets the elements of the DCM matrixto the corresponding elements of the identity matrix.

void	IMU_dcmResetZ (float dcm[3][3])
	DCM reset, Z direction.

void	IMU_dcmRotate (float dcm[3][3], float angle[3])
	Rotates the DCM matrix by a given angle.

uint32_t	IMU_deInit (void)
	De-initializes the IMU chip.

void	IMU_fuseAccelerometerSetSampleRate ( IMU_SensorFusion *f, float rate)
	Sets the accelerometer sample rate in the IMU_SensorFusion structure.

void	IMU_fuseAccelerometerUpdateFilter ( IMU_SensorFusion *f, float avec[3])
	The current accelerometer data is added to the accumulator.

void	IMU_fuseGyroCorrection ( IMU_SensorFusion *f, bool accValid, bool dirValid, float dirZ)
	Calculates the gyro correction vector.

void	IMU_fuseGyroCorrectionClear ( IMU_SensorFusion *f)
	Clears the gyro correction vector.

void	IMU_fuseGyroSetSampleRate ( IMU_SensorFusion *f, float rate)
	Sets the gyro sample rate and related values in the IMU_SensorFusion structure.

void	IMU_fuseGyroUpdate ( IMU_SensorFusion *f, float gvec[3])
	Updates the fusion calculation with a new gyro data.

void	IMU_fuseNew ( IMU_SensorFusion *f)
	Initializes a new IMU_SensorFusion structure.

void	IMU_fuseReset ( IMU_SensorFusion *f)
	Clears the values of the sensor fusion object.

void	IMU_fuseUpdate ( IMU_SensorFusion *f)
	Updates the fusion calculation.

void	IMU_getAccelerometerData (float avec[3])
	Retrieves the raw acceleration data from the IMU.

void	IMU_getGyroCorrectionAngles (float acorr[3])
	Retrieves the processed gyroscope correction angles.

void	IMU_getGyroData (float gvec[3])
	Retrieves the raw gyroscope data from the IMU.

uint8_t	IMU_getState (void)
	Returns IMU state.

uint32_t	IMU_gyroCalibrate (void)
	Performs gyroscope calibration to cancel gyro bias.

void	IMU_gyroGet (int16_t gvec[3])
	Retrieves the processed gyroscope data.

uint32_t	IMU_init (void)
	Initializes and calibrates the IMU.

bool	IMU_isDataReady (void)
	Checks if there is new accel/gyro data available for read.

bool	IMU_isDataReadyFlag (void)
	Checks if there is new accel/gyro data available for read. In case of ver 0.3.0 and older of the PIC firmware the state of the PIC_INT_WAKE needs to be read to determinte if the IMU interrupt is valid.

void	IMU_matrixMultiply (float c[3][3], float a[3][3], float b[3][3])
	Multiplies two 3x3 matrices.

void	IMU_normalizeAngle (float *a)
	Normalizes the angle ( -PI < angle <= PI )

void	IMU_orientationGet (int16_t ovec[3])
	Retrieves the processed orientation data.

void	IMU_reset (void)
	Resets the fusion calculation.

void	IMU_update (void)
	Gets a new set of data from the accel and gyro sensor and updates the fusion calculation.

void	IMU_vectorAdd (float r[3], float a[3], float b[3])
	Adds two vectors.

void	IMU_vectorCrossProduct (float r[3], float a[3], float b[3])
	Calculates the cross product of two vectors.

float	IMU_vectorDotProduct (float a[3], float b[3])
	Calculates the dot product of two vectors.

void	IMU_vectorNormalizeAngle (float v[3])
	Normalizes the angle of a vector.

void	IMU_vectorScalarMultiplication (float r[3], float v[3], float scale)
	Multiplies a vector by a scalar.

void	IMU_vectorScale (float v[3], float scale)
	Scales a vector by a factor.

void	IMU_vectorSubtract (float r[3], float a[3], float b[3])
	Subtracts vector b from vector a.

void	IMU_vectorZero (float v[3])
	Sets all elements of a vector to 0.

Error Codes
#define	IMU_OK 0

State Definitions
#define	IMU_STATE_DISABLED 0x00

#define	IMU_STATE_READY 0x01

#define	IMU_STATE_INITIALIZING 0x02

#define	IMU_STATE_CALIBRATING 0x03

Macro Definition Documentation

#define IMU_OK 0

No errors

Definition at line 39 of file imu.h .

Referenced by IMU_gyroCalibrate() .

#define IMU_STATE_CALIBRATING 0x03

The IMU is being calibrated

Definition at line 59 of file imu.h .

Referenced by IMU_init() .

#define IMU_STATE_DISABLED 0x00

The IMU is disabled

Definition at line 56 of file imu.h .

Referenced by IMU_deInit() , and IMU_init() .

#define IMU_STATE_INITIALIZING 0x02

The IMU is being initialized

Definition at line 58 of file imu.h .

Referenced by IMU_config() , and IMU_init() .

#define IMU_STATE_READY 0x01

The IMU is fully configured and ready to take measurements

Definition at line 57 of file imu.h .

Referenced by IMU_config() , IMU_fuseUpdate() , IMU_getAccelerometerData() , IMU_getGyroData() , IMU_isDataReady() , and IMU_isDataReadyFlag() .

Function Documentation

void IMU_accelerationGet ( int16_t avec[3] )

Retrieves the processed acceleration data.

Parameters

[out] avec Three dimensonal acceleration vector

Returns: None

Definition at line 231 of file imu.c .

References _IMU_SensorFusion::aAccumulator , and _IMU_SensorFusion::aAccumulatorCount .

void IMU_clearDataReadyFlag ( void )

Clears the IMU data ready flag. In case of ver 0.3.0 and older of the PIC firmware the interrupt register also needs to be cleared.

Returns: None

Definition at line 464 of file imu.c .

References BOARD_imuClearIRQ() .

void IMU_config ( float sampleRate )

Configures the IMU.

Parameters

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

Returns: None

IMU general use

Definition at line 165 of file imu.c .

References BOARD_imuClearIRQ() , BOARD_imuEnableIRQ() , BOARD_imuSetIRQCallback() , ICM20648_ACCEL_BW_1210HZ , ICM20648_ACCEL_FULLSCALE_2G , ICM20648_accelBandwidthSet() , ICM20648_accelFullscaleSet() , ICM20648_accelSampleRateSet() , ICM20648_GYRO_BW_51HZ , ICM20648_GYRO_FULLSCALE_250DPS , ICM20648_gyroBandwidthSet() , ICM20648_gyroFullscaleSet() , ICM20648_gyroSampleRateSet() , ICM20648_interruptEnable() , ICM20648_interruptStatusRead() , ICM20648_lowPowerModeEnter() , ICM20648_sensorEnable() , IMU_fuseAccelerometerSetSampleRate() , IMU_fuseGyroSetSampleRate() , IMU_fuseReset() , IMU_STATE_INITIALIZING , IMU_STATE_READY , and UTIL_delay() .

Referenced by IMU_gyroCalibrate() .

void IMU_dcmGetAngles	(	float	`dcm[3][3],`
		float	`angle[3]`
	)

Calculates the Euler angles (roll, pitch, yaw) from the DCM matrix.

Parameters

[in]	`dcm`	DCM matrix
[out]	`angle`	An array containing the Euler angles

Returns: None

Definition at line 173 of file imu_dcm.c .

Referenced by IMU_fuseGyroUpdate() .

void IMU_dcmNormalize ( float dcm[3][3] )

Normalizes the DCM matrix.

Parameters

dcm DCM matrix

Returns: None

Definition at line 128 of file imu_dcm.c .

References IMU_vectorAdd() , IMU_vectorCrossProduct() , IMU_vectorDotProduct() , and IMU_vectorScalarMultiplication() .

Referenced by IMU_fuseGyroUpdate() .

void IMU_dcmReset ( float dcm[3][3] )

Sets the elements of the DCM matrixto the corresponding elements of the identity matrix.

Direction Cosine Matrix functions

Parameters

dcm DCM matrix

Returns: None

Definition at line 41 of file imu_dcm.c .

Referenced by IMU_fuseReset() .

void IMU_dcmResetZ ( float dcm[3][3] )

DCM reset, Z direction.

Parameters

dcm DCM matrix

Returns: None

Definition at line 64 of file imu_dcm.c .

References IMU_vectorCrossProduct() , and IMU_vectorScale() .

void IMU_dcmRotate	(	float	`dcm[3][3],`
		float	`angle[3]`
	)

Rotates the DCM matrix by a given angle.

Parameters

`dcm`	DCM matrix
`angle`	Rotation angle

Returns: None

Definition at line 89 of file imu_dcm.c .

References IMU_matrixMultiply() .

Referenced by IMU_fuseGyroUpdate() .

uint32_t IMU_deInit ( void )

De-initializes the IMU chip.

Returns: Returns zero on OK, non-zero otherwise

Definition at line 133 of file imu.c .

References ICM20648_deInit() , and IMU_STATE_DISABLED .

Referenced by IMU_gyroCalibrate() .

void IMU_fuseAccelerometerSetSampleRate	(	IMU_SensorFusion *	`f,`
		float	`rate`
	)

Sets the accelerometer sample rate in the IMU_SensorFusion structure.

Sensor Fusion functions

Parameters

[out]	`f`	Pointer to the IMU_SensorFusion object
[in]	`rate`	Sample rate of the accelerometer

Returns: None

Definition at line 117 of file imu_fuse.c .

References _IMU_SensorFusion::gSampleRate .

Referenced by IMU_config() .

void IMU_fuseAccelerometerUpdateFilter	(	IMU_SensorFusion *	`f,`
		float	`avec[3]`
	)

The current accelerometer data is added to the accumulator.

Parameters

[out]	`f`	Pointer to the IMU_SensorFusion object
[in]	`avec`	Accelerometer vector

Returns: None

Definition at line 137 of file imu_fuse.c .

References _IMU_SensorFusion::aAccumulator , and _IMU_SensorFusion::aAccumulatorCount .

Referenced by IMU_fuseUpdate() .

void IMU_fuseGyroCorrection	(	IMU_SensorFusion *	`f,`
		bool	`accValid,`
		bool	`dirValid,`
		float	`dirZ`
	)

Calculates the gyro correction vector.

Parameters

[out]	`f`	Pointer to the IMU_SensorFusion object
[in]	`accValid`	True if the acceration value is within the limits
[in]	`dirValid`	True if the direction value is valid
[in]	`dirZ`	The direction of the Z axis

Returns: None

Definition at line 216 of file imu_fuse.c .

References _IMU_SensorFusion::angleCorrection , _IMU_SensorFusion::aVector , _IMU_SensorFusion::gSampleRate , IMU_vectorNormalizeAngle() , IMU_vectorScale() , IMU_vectorSubtract() , IMU_vectorZero() , and _IMU_SensorFusion::orientation .

Referenced by IMU_fuseUpdate() .

void IMU_fuseGyroCorrectionClear ( IMU_SensorFusion * f )

Clears the gyro correction vector.

Parameters

[out] f Pointer to the IMU_SensorFusion object

Returns: None

Definition at line 158 of file imu_fuse.c .

References _IMU_SensorFusion::angleCorrection , and IMU_vectorZero() .

void IMU_fuseGyroSetSampleRate	(	IMU_SensorFusion *	`f,`
		float	`rate`
	)

Sets the gyro sample rate and related values in the IMU_SensorFusion structure.

Parameters

[out]	`f`	Pointer to the IMU_SensorFusion object
[in]	`rate`	Sample rate of the gyroscope

Returns: None

Definition at line 95 of file imu_fuse.c .

References _IMU_SensorFusion::gDeltaTime , _IMU_SensorFusion::gDeltaTimeScale , and _IMU_SensorFusion::gSampleRate .

Referenced by IMU_config() .

void IMU_fuseGyroUpdate	(	IMU_SensorFusion *	`f,`
		float	`gvec[3]`
	)

Updates the fusion calculation with a new gyro data.

Parameters

[out]	`f`	Pointer to the IMU_SensorFusion object
[in]	`gvec`	Gyroscope vector

Returns: None

Definition at line 178 of file imu_fuse.c .

References _IMU_SensorFusion::angleCorrection , _IMU_SensorFusion::dcm , _IMU_SensorFusion::gDeltaTimeScale , IMU_dcmGetAngles() , IMU_dcmNormalize() , IMU_dcmRotate() , IMU_vectorAdd() , IMU_vectorScalarMultiplication() , and _IMU_SensorFusion::orientation .

Referenced by IMU_fuseUpdate() .

void IMU_fuseNew ( IMU_SensorFusion * f )

Initializes a new IMU_SensorFusion structure.

Parameters

[out] f Pointer to the IMU_SensorFusion object to be initialized

Returns: None

Definition at line 48 of file imu_fuse.c .

References _IMU_SensorFusion::aAccumulator , _IMU_SensorFusion::aAccumulatorCount , _IMU_SensorFusion::angleCorrection , _IMU_SensorFusion::aSampleRate , _IMU_SensorFusion::aVector , _IMU_SensorFusion::dcm , _IMU_SensorFusion::gDeltaTime , _IMU_SensorFusion::gSampleRate , _IMU_SensorFusion::gVector , and _IMU_SensorFusion::orientation .

Referenced by IMU_init() .

void IMU_fuseReset ( IMU_SensorFusion * f )

Clears the values of the sensor fusion object.

Parameters

[out] f Pointer to the IMU_SensorFusion object

Returns: None

Definition at line 301 of file imu_fuse.c .

References _IMU_SensorFusion::aAccumulator , _IMU_SensorFusion::aAccumulatorCount , _IMU_SensorFusion::angleCorrection , _IMU_SensorFusion::aVector , _IMU_SensorFusion::dcm , _IMU_SensorFusion::gVector , IMU_dcmReset() , IMU_vectorZero() , and _IMU_SensorFusion::orientation .

Referenced by IMU_config() , and IMU_reset() .

void IMU_fuseUpdate ( IMU_SensorFusion * f )

Updates the fusion calculation.

Parameters

[out] f Pointer to the IMU_SensorFusion object

Returns: None

Definition at line 325 of file imu_fuse.c .

References _IMU_SensorFusion::aVector , _IMU_SensorFusion::gVector , IMU_fuseAccelerometerUpdateFilter() , IMU_fuseGyroCorrection() , IMU_fuseGyroUpdate() , IMU_getAccelerometerData() , IMU_getGyroData() , and IMU_STATE_READY .

Referenced by IMU_update() .

void IMU_getAccelerometerData ( float avec[3] )

Retrieves the raw acceleration data from the IMU.

Parameters

[out] avec Three dimensonal raw acceleration vector

Returns: None

Definition at line 351 of file imu.c .

References ICM20648_accelDataRead() , and IMU_STATE_READY .

Referenced by IMU_fuseUpdate() .

void IMU_getGyroCorrectionAngles ( float acorr[3] )

Retrieves the processed gyroscope correction angles.

Parameters

[out] acorr Three dimensonal gyro correction angle vector

Returns: None

Definition at line 375 of file imu.c .

References _IMU_SensorFusion::angleCorrection .

void IMU_getGyroData ( float gvec[3] )

Retrieves the raw gyroscope data from the IMU.

Parameters

[out] gvec Three dimensonal raw gyro vector

Returns: None

Definition at line 394 of file imu.c .

References ICM20648_gyroDataRead() , and IMU_STATE_READY .

Referenced by IMU_fuseUpdate() .

uint8_t IMU_getState ( void )

Returns IMU state.

Returns: Returns zero on OK, non-zero otherwise

Definition at line 150 of file imu.c .

uint32_t IMU_gyroCalibrate ( void )

Performs gyroscope calibration to cancel gyro bias.

Returns: None

Definition at line 294 of file imu.c .

References ICM20648_interruptEnable() , IMU_config() , IMU_deInit() , IMU_init() , and IMU_OK .

void IMU_gyroGet ( int16_t gvec[3] )

Retrieves the processed gyroscope data.

Parameters

[out] gvec Three dimensonal gyro vector

Returns: None

Definition at line 278 of file imu.c .

References _IMU_SensorFusion::gVector .

uint32_t IMU_init ( void )

Initializes and calibrates the IMU.

Returns: Returns zero on OK, non-zero otherwise

Module functions

Definition at line 74 of file imu.c .

References GPIOINT_Init() , ICM20648_deInit() , ICM20648_getDeviceID() , ICM20648_gyroCalibrate() , ICM20648_init() , ICM20648_OK , IMU_fuseNew() , IMU_STATE_CALIBRATING , IMU_STATE_DISABLED , and IMU_STATE_INITIALIZING .

Referenced by IMU_gyroCalibrate() .

bool IMU_isDataReady ( void )

Checks if there is new accel/gyro data available for read.

Returns: True if the measurement data is ready, false otherwise

Definition at line 415 of file imu.c .

References ICM20648_isDataReady() , and IMU_STATE_READY .

bool IMU_isDataReadyFlag ( void )

Checks if there is new accel/gyro data available for read. In case of ver 0.3.0 and older of the PIC firmware the state of the PIC_INT_WAKE needs to be read to determinte if the IMU interrupt is valid.

Returns: True if data ready flag is set, false otherwise

Definition at line 443 of file imu.c .

References IMU_STATE_READY .

void IMU_matrixMultiply	(	float	`c[3][3],`
		float	`a[3][3],`
		float	`b[3][3]`
	)

Multiplies two 3x3 matrices.

Parameters

[out]	`c`	The multiplication result, AB
[in]	`a`	Input vector A
[in]	`b`	Input vector B

Returns: None

Definition at line 67 of file imu_math.c .

Referenced by IMU_dcmRotate() .

void IMU_normalizeAngle ( float * a )

Normalizes the angle ( -PI < angle <= PI )

Vector and Matrix math

Parameters

`a`	The angle to be normalized

Returns: None

Definition at line 38 of file imu_math.c .

Referenced by IMU_vectorNormalizeAngle() .

void IMU_orientationGet ( int16_t ovec[3] )

Retrieves the processed orientation data.

Parameters

[out] ovec Three dimensonal orientation vector

Returns: None

Definition at line 259 of file imu.c .

References _IMU_SensorFusion::orientation .

void IMU_reset ( void )

Resets the fusion calculation.

Returns: None

Definition at line 334 of file imu.c .

References IMU_fuseReset() .

void IMU_update ( void )

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

Returns: None

Definition at line 320 of file imu.c .

References IMU_fuseUpdate() .

void IMU_vectorAdd	(	float	`r[3],`
		float	`a[3],`
		float	`b[3]`
	)

Adds two vectors.

Parameters

[out]	`r`	The vectorial sum of the vectors, a+b
[in]	`a`	The first vector
[in]	`b`	The second vector

Returns: None

Definition at line 193 of file imu_math.c .

Referenced by IMU_dcmNormalize() , and IMU_fuseGyroUpdate() .

void IMU_vectorCrossProduct	(	float	`r[3],`
		float	`a[3],`
		float	`b[3]`
	)

Calculates the cross product of two vectors.

Parameters

[out]	`r`	The cross product
[in]	`a`	The first vector
[in]	`b`	The second vector

Returns: None

Definition at line 273 of file imu_math.c .

Referenced by IMU_dcmNormalize() , and IMU_dcmResetZ() .

float IMU_vectorDotProduct	(	float	`a[3],`
		float	`b[3]`
	)

Calculates the dot product of two vectors.

Parameters

[in]	`a`	The first vector
[in]	`b`	The second vector

Returns: The dot product

Definition at line 244 of file imu_math.c .

Referenced by IMU_dcmNormalize() .

void IMU_vectorNormalizeAngle ( float v[3] )

Normalizes the angle of a vector.

Parameters

`v`	The vector, which contains angles to be normalized

Returns: None

Definition at line 94 of file imu_math.c .

References IMU_normalizeAngle() .

Referenced by IMU_fuseGyroCorrection() .

void IMU_vectorScalarMultiplication	(	float	`r[3],`
		float	`v[3],`
		float	`scale`
	)

Multiplies a vector by a scalar.

Parameters

[out]	`r`	The multiplied vector
[in]	`v`	The vector to be multiplied
[in]	`scale`	The scalar multiplicator value

Returns: None

Definition at line 142 of file imu_math.c .

Referenced by IMU_dcmNormalize() , and IMU_fuseGyroUpdate() .

void IMU_vectorScale	(	float	`v[3],`
		float	`scale`
	)

Scales a vector by a factor.

Parameters

	`v`	The vector to be scaled
[in]	`scale`	The scale factor

Returns: None

Definition at line 166 of file imu_math.c .

Referenced by IMU_dcmResetZ() , and IMU_fuseGyroCorrection() .

void IMU_vectorSubtract	(	float	`r[3],`
		float	`a[3],`
		float	`b[3]`
	)

Subtracts vector b from vector a.

Parameters

[out]	`r`	The vectorial difference, a-b
[in]	`a`	Vector a
[in]	`b`	Vector b

Returns: None

Definition at line 220 of file imu_math.c .

Referenced by IMU_fuseGyroCorrection() .

void IMU_vectorZero ( float v[3] )

Sets all elements of a vector to 0.

Parameters

`v`	The vector to be cleared

Returns: None

Definition at line 115 of file imu_math.c .

Referenced by IMU_fuseGyroCorrection() , IMU_fuseGyroCorrectionClear() , and IMU_fuseReset() .

IMU - Inertial Measurement UnitBSP > Thunderboard Sense BSP

Detailed Description

Data Structures

Typedefs

Functions

Error Codes

State Definitions

Macro Definition Documentation

Function Documentation