lejos.nxt.addon
Class DIMUAccel

java.lang.Object
  lejos.nxt.I2CSensor
      lejos.nxt.addon.DIMUAccel

All Implemented Interfaces:

SensorConstants, Accelerometer

public class DIMUAccel
extends I2CSensor
implements Accelerometer

This class provides access to the accelerometer of Dexter Industries IMU sensor

Version:

1.0

Author:

Aswin Bouwmeester

Nested Class Summary

static class	DIMUAccel.AccelUnits List of possible units for acceleration
static class	DIMUAccel.TiltUnits List of possible units for Tilt

Field Summary

protected static int	ACCEL
protected DIMUAccel.AccelUnits	accelUnit The default unit to use when retuning acceleration data from the accelerometer
protected static int	DEFAULT_I2C_ADDRESS
protected static int	MODE_REG
protected float	multiplier A factor to use when converting raw data from the accelerometer.
protected float[]	offset
protected static int	samples
protected float[]	scale
protected DIMUAccel.TiltUnits	tiltUnit The default unit to use when retuning tilt data from the accelerometer

Fields inherited from class lejos.nxt.I2CSensor

address, port, REG_PRODUCT_ID, REG_VENDOR_ID, REG_VERSION

Fields inherited from interface lejos.nxt.SensorConstants

BLACK, BLANK_INDEX, BLUE, BLUE_INDEX, GREEN, GREEN_INDEX, MAX_AD_RAW, MAX_TYPE, MIN_TYPE, MODE_ANGLESTEP, MODE_BOOLEAN, MODE_CELSIUS, MODE_FARENHEIT, MODE_PCTFULLSCALE, MODE_PERIODCOUNTER, MODE_RAW, MODE_TRANSITIONCNT, RED, RED_INDEX, TYPE_ANGLE, TYPE_COLORBLUE, TYPE_COLORFULL, TYPE_COLORGREEN, TYPE_COLORNONE, TYPE_COLORRED, TYPE_CUSTOM, TYPE_HISPEED, TYPE_LIGHT_ACTIVE, TYPE_LIGHT_INACTIVE, TYPE_LOWSPEED, TYPE_LOWSPEED_9V, TYPE_NO_SENSOR, TYPE_REFLECTION, TYPE_SOUND_DB, TYPE_SOUND_DBA, TYPE_SWITCH, TYPE_TEMPERATURE, WHITE, YELLOW

Constructor Summary

DIMUAccel(I2CPort port)

Method Summary

void	calibrateAxis(char axis) Calibrates a single axis.
void	fetchAllAccel(float[] ret) Acceleration along 3 axis.
void	fetchAllAccel(float[] ret, DIMUAccel.AccelUnits unit) Acceleration along 3 axis.
void	fetchAllTilt(float[] ret) Tilt along 3 axis
void	fetchAllTilt(float[] ret, DIMUAccel.TiltUnits unit) Tilt along 3 axis.
void	fetchRawAccel(int[] ret)
DIMUAccel.AccelUnits	getAccelUnit() Returns the current acceleration unit
protected float	getMultiplier()
String	getProductID() Read the sensor's product identifier.
DIMUAccel.TiltUnits	getTiltUnit() Returns the current unit for tilt
String	getVendorID() Read the sensor's vendor identifier.
String	getVersion() Read the sensor's version string.
int	getXAccel() Measures the x-axis of the accelerometer, in meters/second^2.
int	getYAccel() Measures the y-axis of the accelerometer, in meters/second^2.
int	getZAccel() Measures the z-axis of the accelerometer, in meters/second^2.
void	load() Loads saved offset and scale values from memory.
void	save() Saves the offset and scale factors in Flash memory.
void	setAccelUnit(DIMUAccel.AccelUnits accelUnit) Sets the unit for acceleration
void	setTiltUnit(DIMUAccel.TiltUnits tiltUnit) Sets the unit for tilt

Methods inherited from class lejos.nxt.I2CSensor

fetchString, getAddress, getData, getData, getPort, sendData, sendData, sendData, setAddress

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ACCEL

protected static final int ACCEL

See Also:

Constant Field Values

MODE_REG

protected static final int MODE_REG

See Also:

Constant Field Values

DEFAULT_I2C_ADDRESS

protected static final int DEFAULT_I2C_ADDRESS

See Also:

Constant Field Values

offset

protected float[] offset

scale

protected float[] scale

samples

protected static int samples

accelUnit

protected DIMUAccel.AccelUnits accelUnit

The default unit to use when retuning acceleration data from the accelerometer

tiltUnit

protected DIMUAccel.TiltUnits tiltUnit

The default unit to use when retuning tilt data from the accelerometer

multiplier

protected float multiplier

A factor to use when converting raw data from the accelerometer. multiplier corresponds to 1 / Number of least significant bits per unit. This number and the unit are given in the documentation of the sensor.

Constructor Detail

DIMUAccel

public DIMUAccel(I2CPort port)

Parameters:

port -

Method Detail

calibrateAxis

public void calibrateAxis(char axis)

Calibrates a single axis. The calibration process consists of determining static acceleration values due to gravity by placing the axis opposite and in the direction of gravity. This gives a minimum and maximum value. The difference between the two is equal to 2G and used to calculate a scale factor. The mean of the two corresponds to 0G and equals the offset value.

Calibration settings are held in memory. To store these values one should use the save() method.

Parameters:

axis - Axis should have the value X,Y or Z

fetchAllAccel

public void fetchAllAccel(float[] ret)

Acceleration along 3 axis.

fetchAllAccel

public void fetchAllAccel(float[] ret,
                          DIMUAccel.AccelUnits unit)

Acceleration along 3 axis.

Parameters:

unit - of acceleration

fetchAllTilt

public void fetchAllTilt(float[] ret)

Tilt along 3 axis

fetchAllTilt

public void fetchAllTilt(float[] ret,
                         DIMUAccel.TiltUnits unit)

Tilt along 3 axis. Calculation of tilt is based acceleration and on the fact that under static circumstances (no acceleration) the accleration (in G) equals the cosine of the tilt angle.

Parameters:

unit - of tilt

fetchRawAccel

public void fetchRawAccel(int[] ret)

getAccelUnit

public DIMUAccel.AccelUnits getAccelUnit()

Returns the current acceleration unit

Returns:

accelUnit

getMultiplier

protected float getMultiplier()

Returns:

A factor to use when converting raw data from the accelerometer.

getProductID

public String getProductID()

Description copied from class: I2CSensor

Read the sensor's product identifier. This method reads up to 8 bytes and returns the characters before the zero termination byte. Examples: "Sonar", ...

Overrides:

getProductID in class I2CSensor

Returns:

product identifier

getVendorID

public String getVendorID()

Description copied from class: I2CSensor

Read the sensor's vendor identifier. This method reads up to 8 bytes and returns the characters before the zero termination byte. Examples: "LEGO", "HiTechnc", ...

Overrides:

getVendorID in class I2CSensor

Returns:

vendor identifier

getTiltUnit

public DIMUAccel.TiltUnits getTiltUnit()

Returns the current unit for tilt

Returns:

getVersion

public String getVersion()

Description copied from class: I2CSensor

Read the sensor's version string. This method reads up to 8 bytes and returns the characters before the zero termination byte. Examples: "V1.0", ...

Overrides:

getVersion in class I2CSensor

Returns:

version number

load

public void load()

Loads saved offset and scale values from memory. If no saved values are found it will load default values for offset=0 and scale =1;

save

public void save()

Saves the offset and scale factors in Flash memory.

setAccelUnit

public void setAccelUnit(DIMUAccel.AccelUnits accelUnit)

Sets the unit for acceleration

Parameters:

accelUnit -

setTiltUnit

public void setTiltUnit(DIMUAccel.TiltUnits tiltUnit)

Sets the unit for tilt

Parameters:

tiltUnit -

getXAccel

public int getXAccel()

Description copied from interface: Accelerometer

Measures the x-axis of the accelerometer, in meters/second^2.

Specified by:

getXAccel in interface Accelerometer

Returns:

acceleration in m/s^2

getYAccel

public int getYAccel()

Description copied from interface: Accelerometer

Measures the y-axis of the accelerometer, in meters/second^2.

Specified by:

getYAccel in interface Accelerometer

Returns:

acceleration in m/s^2

getZAccel

public int getZAccel()

Description copied from interface: Accelerometer

Measures the z-axis of the accelerometer, in meters/second^2.

Specified by:

getZAccel in interface Accelerometer

Returns:

acceleration in m/s^2