Initial support of the FXOS8700CQ; a combined triple axis accelerometer and magnetometer. More...

#include <FXOS8700CQ.hpp>

Inheritance diagram for duds::hardware::devices::instruments::FXOS8700CQ:

Collaboration diagram for duds::hardware::devices::instruments::FXOS8700CQ:

Classes
union	RawSample
	Stores the sample data as reported by the device. More...

struct	Settings
	The various settings for the device packed into an integer to avoid passing a lot of parameters. More...

Public Types
typedef duds::data::QuantityXyz	ConvertedSample
	The sample data converted to known units. More...

enum	Magnitude { Magnitude2g, Magnitude4g, Magnitude8g }
	The magnitude options for the accelerometer. More...

enum	OversampleMode { Normal, LowNoiseLowPower, HighResolution, LowPower }

Public Member Functions
	FXOS8700CQ (std::unique_ptr< duds::hardware::interface::I2c > &i2ccom)
	Attempts to identify the device, then suspends the device's operation. More...

	~FXOS8700CQ ()
	Calls suspend(). More...

void	configure (float freq, Settings settings)
	Configures the device. More...

const RawSample &	rawAccelerometer () const
	Returns the accelerometer data as read from the device. More...

const RawSample &	rawMagnetometer () const
	Returns the magnetometer data as read from the device. More...

void	resume ()
	Resumes operation after a call to suspend(). More...

bool	sample ()
	Reads sampled data from the device. More...

float	sampleRate () const
	Returns the confiured sampling rate. More...

void	start ()
	Tells the device to start sampling. More...

void	suspend ()
	Suspends operation by putting the device into a low-power mode that discontinues sampling. More...

Private Attributes
RawSample	accl
	The values supplied by the device. More...

duds::hardware::interface::Conversation	bufq

Settings	cfg
	The current various configuration options. More...

std::unique_ptr< duds::hardware::interface::I2c >	com
	The I2C communication interface. More...

float	datarate
	The currently configured sample rate. More...

std::int8_t	drval
	The data rate value given to the device. More...

duds::hardware::interface::Conversation	initialize
	The conversation used to initialize the device. More...

duds::hardware::interface::Conversation	input
	The conversation used to read in samples from the device. More...

RawSample	magn

Detailed Description

Initial support of the FXOS8700CQ; a combined triple axis accelerometer and magnetometer.

Errata document says any communication over I2C will adversely affect any magnetometer sample by as much as 70uT. This likely will be triggered by any use of the I2C bus rather than just communication with the FXOS8700CQ.

Adafruit's board uses device address 0x1F. When using the board with the I2C bus on HDMI from a notebook computer, I found that the reset operation causes the device to ignore all communication until after a power cycle. Not sure why. I also found that with that setup and certain almost but not quite level orientations, the device fails to register gravity. It also has issues with the magnetometer data. Using the same device with a Raspberry Pi resulted in good accelerometer data, but bad magnetometer data. Could just be an issue with the board I have.

Author: Jeff Jackowski

Definition at line 56 of file FXOS8700CQ.hpp.

Member Typedef Documentation

◆ ConvertedSample

typedef duds::data::QuantityXyz duds::hardware::devices::instruments::FXOS8700CQ::ConvertedSample

The sample data converted to known units.

The accelerometer data is a bit of a guess since its units are vaugely defined and callibration is done based on the local pull of Earth's gravity.

Definition at line 75 of file FXOS8700CQ.hpp.

Member Enumeration Documentation

◆ Magnitude

enum duds::hardware::devices::instruments::FXOS8700CQ::Magnitude

The magnitude options for the accelerometer.

Enumerator

Magnitude2g

Selects the +/-2g accelerometer range.

Magnitude4g

Selects the +/-4g accelerometer range.

Magnitude8g

Selects the +/-8g accelerometer range.

Cannot be used with the low-noise operating mode.

Definition at line 79 of file FXOS8700CQ.hpp.

◆ OversampleMode

enum duds::hardware::devices::instruments::FXOS8700CQ::OversampleMode

Enumerator
Normal
LowNoiseLowPower
HighResolution
LowPower

Definition at line 94 of file FXOS8700CQ.hpp.

Constructor & Destructor Documentation

◆ FXOS8700CQ()

duds::hardware::devices::instruments::FXOS8700CQ::FXOS8700CQ ( std::unique_ptr< duds::hardware::interface::I2c > & i2ccom )

Attempts to identify the device, then suspends the device's operation.

This resets the device, which requires 2ms to complete.

Adafruit's board uses device address 0x1F.

Parameters

i2ccom The I2C object to use to communicate with the device. This FXOS8700CQ object will take ownership over i2ccom.

Exceptions

DeviceMisidentified The reported device ID is incorrect.

Definition at line 88 of file FXOS8700CQ.cpp.

◆ ~FXOS8700CQ()

duds::hardware::devices::instruments::FXOS8700CQ::~FXOS8700CQ ( )

Calls suspend().

Definition at line 132 of file FXOS8700CQ.cpp.

Member Function Documentation

◆ configure()

void duds::hardware::devices::instruments::FXOS8700CQ::configure	(	float	freq,
		Settings	settings
	)

Configures the device.

Postcondition: The device will be suspended.

Parameters

freq	The minimum sample frequency. If the rate is too high, FXOS8700CQBadDataRate will be thrown.
settings	The requested device configuration.

Exceptions

FXOS8700CQNoInsturment	The configuration does not select either the accelerometer or magnetometer for use.
FXOS8700CQBadMagnitude	The requested maximum magnetude for the accelerometer is either not supported or an invalid value.
FXOS8700CQBadDataRate

Definition at line 148 of file FXOS8700CQ.cpp.

◆ rawAccelerometer()

const RawSample& duds::hardware::devices::instruments::FXOS8700CQ::rawAccelerometer ( ) const

inline

Returns the accelerometer data as read from the device.

The data will be shifted, if needed, so that the LSb of the sample data will be in the LSb of the integers. Otherwise, the data is unchanged from what the device reported.

Note: The values will change when the device is sampled and the accelerometer is in use.

Definition at line 258 of file FXOS8700CQ.hpp.

◆ rawMagnetometer()

const RawSample& duds::hardware::devices::instruments::FXOS8700CQ::rawMagnetometer ( ) const

inline

Returns the magnetometer data as read from the device.

Note: The values will change when the device is sampled and the magnetometer is in use.

Definition at line 266 of file FXOS8700CQ.hpp.

◆ resume()

void duds::hardware::devices::instruments::FXOS8700CQ::resume ( )

inline

Resumes operation after a call to suspend().

Seems to be a nice name that I used with other device drivers, so I put it here until I do more to figure out a consistent interface that I like.

Exceptions

DeviceUninitalized init() hasn't been called.

Definition at line 235 of file FXOS8700CQ.hpp.

◆ sample()

bool duds::hardware::devices::instruments::FXOS8700CQ::sample ( )

Reads sampled data from the device.

Returns: True if the device had new data.

Definition at line 328 of file FXOS8700CQ.cpp.

◆ sampleRate()

float duds::hardware::devices::instruments::FXOS8700CQ::sampleRate ( ) const

inline

Returns the confiured sampling rate.

The value will be zero if configure() has not yet been called, or if it failed.

Definition at line 247 of file FXOS8700CQ.hpp.

◆ start()

void duds::hardware::devices::instruments::FXOS8700CQ::start ( )

Tells the device to start sampling.

Precondition: configure() has been called and succeeded.

Definition at line 286 of file FXOS8700CQ.cpp.

◆ suspend()

void duds::hardware::devices::instruments::FXOS8700CQ::suspend ( )

Suspends operation by putting the device into a low-power mode that discontinues sampling.

This may require as much as 300ms to complete if the magnetometer is in use.

Definition at line 303 of file FXOS8700CQ.cpp.

Referenced by configure(), FXOS8700CQ(), and ~FXOS8700CQ().

Member Data Documentation

◆ accl

RawSample duds::hardware::devices::instruments::FXOS8700CQ::accl

private

The values supplied by the device.

Definition at line 172 of file FXOS8700CQ.hpp.

Referenced by sample().

◆ bufq

duds::hardware::interface::Conversation duds::hardware::devices::instruments::FXOS8700CQ::bufq

private

Definition at line 168 of file FXOS8700CQ.hpp.

Referenced by configure(), and sample().

◆ cfg

Settings duds::hardware::devices::instruments::FXOS8700CQ::cfg

private

The current various configuration options.

Definition at line 180 of file FXOS8700CQ.hpp.

Referenced by configure(), FXOS8700CQ(), sample(), start(), and suspend().

◆ com

std::unique_ptr<duds::hardware::interface::I2c> duds::hardware::devices::instruments::FXOS8700CQ::com

private

The I2C communication interface.

Definition at line 159 of file FXOS8700CQ.hpp.

Referenced by configure(), FXOS8700CQ(), sample(), start(), and suspend().

◆ datarate

float duds::hardware::devices::instruments::FXOS8700CQ::datarate

private

The currently configured sample rate.

Definition at line 176 of file FXOS8700CQ.hpp.

Referenced by configure().

◆ drval

std::int8_t duds::hardware::devices::instruments::FXOS8700CQ::drval

private

The data rate value given to the device.

Definition at line 184 of file FXOS8700CQ.hpp.

Referenced by configure(), and start().

◆ initialize

duds::hardware::interface::Conversation duds::hardware::devices::instruments::FXOS8700CQ::initialize

private

The conversation used to initialize the device.

It is created in init() and held for later use by resume().

Definition at line 164 of file FXOS8700CQ.hpp.

◆ input

duds::hardware::interface::Conversation duds::hardware::devices::instruments::FXOS8700CQ::input

private

The conversation used to read in samples from the device.

Definition at line 168 of file FXOS8700CQ.hpp.

Referenced by configure(), and sample().

◆ magn

RawSample duds::hardware::devices::instruments::FXOS8700CQ::magn

private

Definition at line 172 of file FXOS8700CQ.hpp.

Referenced by sample().

The documentation for this class was generated from the following files:

Classes

Public Types

Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ ConvertedSample

Member Enumeration Documentation

◆ Magnitude

◆ OversampleMode

Constructor & Destructor Documentation

◆ FXOS8700CQ()

◆ ~FXOS8700CQ()

Member Function Documentation

◆ configure()

◆ rawAccelerometer()

◆ rawMagnetometer()

◆ resume()

◆ sample()

◆ sampleRate()

◆ start()

◆ suspend()

Member Data Documentation

◆ accl

◆ bufq

◆ cfg

◆ com

◆ datarate

◆ drval

◆ initialize

◆ input

◆ magn