ITG-3200 triple axis digital gyroscope. More...

#include <ITG3200.h>

Public Types
enum	Correction { NoCorrection, OffsetCorrection, Calibration }
	Zero offset correction mode that can be specified when calling getXYZ(). More...
Public Member Functions
	ITG3200 (PinName sda, PinName scl, bool fastmode=false)
	Constructor.
	ITG3200 (I2C &i2c)
	Constructor that accepts external i2c interface object.
void	setCalibrationCurve (const float offset[3], const float slope[3])
	Sets calibration curve parameters.
char	getWhoAmI (void)
	Get the identity of the device.
void	setWhoAmI (char address)
	Set the address of the device.
char	getSampleRateDivider (void)
	Get the sample rate divider.
void	setSampleRateDivider (char divider)
	Set the sample rate divider.
int	getInternalSampleRate (void)
	Get the internal sample rate.
void	setLpBandwidth (char bandwidth)
	Set the low pass filter bandwidth.
char	getInterruptConfiguration (void)
	Get the interrupt configuration.
void	setInterruptConfiguration (char config)
	Set the interrupt configuration.
bool	isPllReady (void)
	Check the ITG_RDY bit of the INT_STATUS register.
bool	isRawDataReady (void)
	Check the RAW_DATA_RDY bit of the INT_STATUS register.
int	getRawTemperature (void)
	Get the temperature in raw format.
float	getTemperature (void)
	Get the temperature of the device.
int	getX (void)
	Get the output for the x-axis gyroscope.
int	getY (void)
	Get the output for the y-axis gyroscope.
int	getZ (void)
	Get the output on the z-axis gyroscope.
void	getXYZ (int16_t readings[3], Correction corr=OffsetCorrection)
	Burst read the outputs on the x,y,z-axis gyroscope.
void	getXYZDegrees (double readings[3], Correction corr=OffsetCorrection)
	Burst read the outputs on the x,y,z-axis gyroscope and convert them into degrees per second.
void	getXYZRadians (double readings[3], Correction corr=OffsetCorrection)
	Burst read the outputs on the x,y,z-axis gyroscope and convert them into degrees per second.
char	getPowerManagement (void)
	Get the power management configuration.
void	setPowerManagement (char config)
	Set power management configuration.
void	calibrate (double time)
	Calibrate the sensor drift by sampling zero offset.
I2C &	getI2C ()
	Returns the I2C object that this object is using for communication.
void	getOffset (int16_t offset_copy[3]) const
	Returns internal offset values for zero adjusting.
Static Public Attributes
static const int	I2C_ADDRESS = 0xD0
	The I2C address that can be passed directly to i2c object (it's already shifted 1 bit left).
Protected Member Functions
int	getWord (int regi)
	Reads a word (2 bytes) from the sensor via I2C bus.
void	getRawXYZ (int16_t readings[3])
	An internal method to acquire gyro sensor readings before calibration correction.
Protected Attributes
float	offset [3]
	Offset values that will be subtracted from output.

Detailed Description

ITG-3200 triple axis digital gyroscope.

Definition at line 88 of file ITG3200.h.

Member Enumeration Documentation

enum Correction

Zero offset correction mode that can be specified when calling getXYZ().

The device has a major drift in readings depending on ambient temperature. You can measure the temperature with built-in thermometer to correct it, but you must have calibration curves for each axes to do so. Here are the options on how to correct the drift.

Enumerator:

NoCorrection	Do not correct zero offset at all; You would have trouble integrating the values to obtain rotation.
OffsetCorrection	Correct the outputs with single-point zero adjust.
Calibration	Use calibration curve (actually lines) to correct the outputs. You must provide coefficients with setCalibrationCurve().

Definition at line 108 of file ITG3200.h.

Constructor & Destructor Documentation

ITG3200	(	PinName	sda,
		PinName	scl,
		bool	fastmode = `false`
	)

Constructor.

Sets FS_SEL to 0x03 for proper opertaion.

Parameters:

sda	- mbed pin to use for the SDA I2C line.
scl	- mbed pin to use for the SCL I2C line.
fastmode	Sets the internal I2C interface to use 400kHz clock.

Definition at line 40 of file ITG3200.cpp.

ITG3200 ( I2C & i2c )

Constructor that accepts external i2c interface object.

Parameters:

i2c	The I2C interface object to use.

Definition at line 131 of file ITG3200.h.

Member Function Documentation

void calibrate ( double time )

Calibrate the sensor drift by sampling zero offset.

Be sure to keep the sensor stationary while sampling offset.

Once this function is invoked, following getXYZ*() functions return corrected values.

If the drift value changes over time, you can call this function once in a while to follow it. But don't forget to fix the sensor while calibrating!

Parameters:

time	The time span to sample and average offset. Sampling rate is limited, so giving long time to calibrate will improve correction quality.

Definition at line 338 of file ITG3200.cpp.

I2C& getI2C ( )

Returns the I2C object that this object is using for communication.

Definition at line 443 of file ITG3200.h.

int getInternalSampleRate ( void )

Get the internal sample rate.

Returns:: The internal sample rate in kHz - either 1 or 8.

Definition at line 161 of file ITG3200.cpp.

char getInterruptConfiguration ( void )

Get the interrupt configuration.

See datasheet for register contents details.

3 2 1 0 +---+------------+------------+---+ | 0 | ITG_RDY_EN | RAW_RDY_EN | 0 | +---+------------+------------+---+

ACTL Logic level for INT output pin; 1 = active low, 0 = active high. OPEN Drive type for INT output pin; 1 = open drain, 0 = push-pull. LATCH_INT_EN Latch mode; 1 = latch until interrupt is cleared, 0 = 50us pulse. INT_ANYRD_2CLEAR Latch clear method; 1 = any register read, 0 = status register read only. ITG_RDY_EN Enable interrupt when device is ready, (PLL ready after changing clock source). RAW_RDY_EN Enable interrupt when data is available. 0 Bits 1 and 3 of the INT_CFG register should be zero.

Returns:: the contents of the INT_CFG register.

Definition at line 198 of file ITG3200.cpp.

void getOffset ( int16_t offset_copy[3] ) const

Returns internal offset values for zero adjusting.

Returned pointer is pointing an array of 3 elements.

Definition at line 450 of file ITG3200.h.

char getPowerManagement ( void )

Get the power management configuration.

See the datasheet for register contents details.

H_RESET Reset device and internal registers to the power-up-default settings. SLEEP Enable low power sleep mode. STBY_XG Put gyro X in standby mode (1=standby, 0=normal). STBY_YG Put gyro Y in standby mode (1=standby, 0=normal). STBY_ZG Put gyro Z in standby mode (1=standby, 0=normal). CLK_SEL Select device clock source:

CLK_SEL | Clock Source --------+-------------- 0 Internal oscillator 1 PLL with X Gyro reference 2 PLL with Y Gyro reference 3 PLL with Z Gyro reference 4 PLL with external 32.768kHz reference 5 PLL with external 19.2MHz reference 6 Reserved 7 Reserved

Returns:: The contents of the PWR_MGM register.

Definition at line 313 of file ITG3200.cpp.

int getRawTemperature ( void )

Get the temperature in raw format.

Returns:: The temperature in raw 16bit integer.

Definition at line 283 of file ITG3200.h.

void getRawXYZ ( int16_t readings[3] ) [protected]

An internal method to acquire gyro sensor readings before calibration correction.

Protected for the time being, although there could be cases that raw values are appreciated by the user.

Definition at line 281 of file ITG3200.cpp.

char getSampleRateDivider ( void )

Get the sample rate divider.

Returns:: The sample rate divider as a number from 0-255.

Definition at line 136 of file ITG3200.cpp.

float getTemperature ( void )

Get the temperature of the device.

Returns:: The temperature in degrees celsius.

Definition at line 274 of file ITG3200.cpp.

char getWhoAmI ( void )

Get the identity of the device.

Returns:: The contents of the Who Am I register which contains the I2C address of the device.

Definition at line 110 of file ITG3200.cpp.

int getWord ( int regi ) [protected]

Reads a word (2 bytes) from the sensor via I2C bus.

The queried value is assumed big-endian, 2's complement value.

This protected function is added because we shouldn't write getX(), getY() and getZ() independently, but collect common codes.

Parameters:

regi	Register address to be read.

Definition at line 261 of file ITG3200.cpp.

int getX ( void )

Get the output for the x-axis gyroscope.

Typical sensitivity is 14.375 LSB/(degrees/sec).

Returns:: The output on the x-axis in raw ADC counts.

Definition at line 299 of file ITG3200.h.

void getXYZ	(	int16_t	readings[3],
		Correction	corr = `OffsetCorrection`
	)

Burst read the outputs on the x,y,z-axis gyroscope.

Typical sensitivity is 14.375 LSB/(degrees/sec).

Parameters:

readings	The output buffer array that has at least 3 length.
corr	Correction method for returned values.

Definition at line 295 of file ITG3200.cpp.

void getXYZDegrees	(	double	readings[3],
		Correction	corr = `OffsetCorrection`
	)

Burst read the outputs on the x,y,z-axis gyroscope and convert them into degrees per second.

Parameters:

readings	The output buffer array that has at least 3 length.
corr	Correction method for returned values.

Definition at line 519 of file ITG3200.h.

void getXYZRadians	(	double	readings[3],
		Correction	corr = `OffsetCorrection`
	)

Burst read the outputs on the x,y,z-axis gyroscope and convert them into degrees per second.

Parameters:

readings	The output buffer array that has at least 3 length.
corr	Correction method for returned values.

Definition at line 526 of file ITG3200.h.

int getY ( void )

Get the output for the y-axis gyroscope.

Typical sensitivity is 14.375 LSB/(degrees/sec).

Returns:: The output on the y-axis in raw ADC counts.

Definition at line 308 of file ITG3200.h.

int getZ ( void )

Get the output on the z-axis gyroscope.

Typical sensitivity is 14.375 LSB/(degrees/sec).

Returns:: The output on the z-axis in raw ADC counts.

Definition at line 317 of file ITG3200.h.

bool isPllReady ( void )

Check the ITG_RDY bit of the INT_STATUS register.

Returns:: True if the ITG_RDY bit is set, corresponding to PLL ready, false if the ITG_RDY bit is not set, corresponding to PLL not ready.

Definition at line 223 of file ITG3200.cpp.

bool isRawDataReady ( void )

Check the RAW_DATA_RDY bit of the INT_STATUS register.

Returns:: True if the RAW_DATA_RDY bit is set, corresponding to new data in the sensor registers, false if the RAW_DATA_RDY bit is not set, corresponding to no new data yet in the sensor registers.

Definition at line 242 of file ITG3200.cpp.

void setCalibrationCurve	(	const float	offset[3],
		const float	slope[3]
	)

Sets calibration curve parameters.

Parameters:

offset	An array holding calibration curve offsets (0th-order coefficient) for each axis, must have 3 elements.
slope	An array holding calibration curve slopes (1st-order coefficient) for each axis, must have 3 elements.

Definition at line 98 of file ITG3200.cpp.

void setInterruptConfiguration ( char config )

Set the interrupt configuration.

See datasheet for configuration byte details.

3 2 1 0 +---+------------+------------+---+ | 0 | ITG_RDY_EN | RAW_RDY_EN | 0 | +---+------------+------------+---+

ACTL Logic level for INT output pin; 1 = active low, 0 = active high. OPEN Drive type for INT output pin; 1 = open drain, 0 = push-pull. LATCH_INT_EN Latch mode; 1 = latch until interrupt is cleared, 0 = 50us pulse. INT_ANYRD_2CLEAR Latch clear method; 1 = any register read, 0 = status register read only. ITG_RDY_EN Enable interrupt when device is ready, (PLL ready after changing clock source). RAW_RDY_EN Enable interrupt when data is available. 0 Bits 1 and 3 of the INT_CFG register should be zero.

Parameters:

config Configuration byte to write to INT_CFG register.

Definition at line 212 of file ITG3200.cpp.

void setLpBandwidth ( char bandwidth )

Set the low pass filter bandwidth.

Also used to set the internal sample rate. Pass the define bandwidth codes as a parameter.

256Hz -> 8kHz internal sample rate. Everything else -> 1kHz internal rate.

Parameters:

bandwidth Low pass filter bandwidth code

Definition at line 186 of file ITG3200.cpp.

void setPowerManagement ( char config )

Set power management configuration.

See the datasheet for configuration byte details

H_RESET Reset device and internal registers to the power-up-default settings. SLEEP Enable low power sleep mode. STBY_XG Put gyro X in standby mode (1=standby, 0=normal). STBY_YG Put gyro Y in standby mode (1=standby, 0=normal). STBY_ZG Put gyro Z in standby mode (1=standby, 0=normal). CLK_SEL Select device clock source:

CLK_SEL | Clock Source --------+-------------- 0 Internal oscillator 1 PLL with X Gyro reference 2 PLL with Y Gyro reference 3 PLL with Z Gyro reference 4 PLL with external 32.768kHz reference 5 PLL with external 19.2MHz reference 6 Reserved 7 Reserved

Parameters:

config The configuration byte to write to the PWR_MGM register.

Definition at line 327 of file ITG3200.cpp.

void setSampleRateDivider ( char divider )

Set the sample rate divider.

Fsample = Finternal / (divider + 1), where Finternal = 1kHz or 8kHz, as decidied by the DLPF_FS register.

Parameters:

The	sample rate divider as a number from 0-255.

Definition at line 150 of file ITG3200.cpp.

void setWhoAmI ( char address )

Set the address of the device.

Parameters:

address The I2C slave address to write to the Who Am I register on the device.

Definition at line 125 of file ITG3200.cpp.

Field Documentation

const int I2C_ADDRESS = 0xD0 [static]

The I2C address that can be passed directly to i2c object (it's already shifted 1 bit left).

You don't need to manually set or clear the LSB when calling I2C::read() or I2C::write(), the library takes care of it. We just always clear the LSB.

Definition at line 98 of file ITG3200.h.

float offset[3] [protected]

Offset values that will be subtracted from output.

TODO: temperature drift calibration

Definition at line 484 of file ITG3200.h.

Type:	Library
Created:	30 Oct 2012
Imports:	23
Forks:	0
Commits:	16
Dependents:	1
Dependencies:	0
Followers:	2

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ITG3200 Class Reference

Public Types

Public Member Functions

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Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

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Field Documentation

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Important changes to repositories hosted on mbed.com

ITG3200 Class Reference

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation

Repository toolbox

Repository details

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