LSM303D Class Reference

API for the LSM303D 3-Axis Geomagnetic Sensor. More...

Detailed Description

• ID: lsm303d
• Name: Ultra-compact high-performance eCompass module
• Category: compass
• Manufacturer: stmicro
• Connection: i2c gpio
• Link: http://www.st.com/en/mems-and-sensors/lsm303d.html

The LSM303D is an ultra-low-power high-performance system-in-package featuring a 3D digital linear acceleration sensor and a 3D digital magnetic sensor. The LSM303D has linear acceleration full scales of 2g/4g/8g/16g and a magnetic field dynamic range of 50 Gauss.

Not all functionality of this chip has been implemented in this driver, however all the pieces are present to add any desired functionality. This driver supports only I2C operation.

This device requires 3.3v operation.

    // Instantiate an LSM303D using default I2C parameters
    upm::LSM303D sensor;

    // now output data every 250 milliseconds
    while (shouldRun) {
        float x, y, z;

        sensor.update();

        sensor.getAccelerometer(&x, &y, &z);
        cout << "Accelerometer x: " << x << " y: " << y << " z: " << z << " g" << endl;

        sensor.getMagnetometer(&x, &y, &z);
        cout << "Magnetometer x: " << x << " y: " << y << " z: " << z << " uT" << endl;

        cout << "Temperature: " << sensor.getTemperature() << " C" << endl;

        cout << endl;

        upm_delay_us(250000);
    }

Public Member Functions
	LSM303D (int bus=LSM303D_DEFAULT_I2C_BUS, int addr=LSM303D_DEFAULT_I2C_ADDR)
	~LSM303D ()
void	update ()
void	getMagnetometer (float *x, float *y, float *z)
std::vector< float >	getMagnetometer ()
void	getAccelerometer (float *x, float *y, float *z)
std::vector< float >	getAccelerometer ()
float	getTemperature ()
void	init (LSM303D_M_RES_T res)
void	setAccelerometerFullScale (LSM303D_AFS_T fs)
void	setMagnetometerFullScale (LSM303D_MFS_T fs)
void	setAccelerometerODR (LSM303D_AODR_T odr)
void	setMagnetometerODR (LSM303D_MODR_T odr)

Protected Member Functions
uint8_t	readReg (uint8_t reg)
int	readRegs (uint8_t reg, uint8_t *buffer, int len)
void	writeReg (uint8_t reg, uint8_t val)

Protected Attributes
lsm303d_context	m_lsm303d

Constructor & Destructor Documentation

LSM303D	(	int	bus = LSM303D_DEFAULT_I2C_BUS,
		int	addr = LSM303D_DEFAULT_I2C_ADDR
	)

LSM303D constructor

This driver only supports I2C.

Due to the fact that this chip is currently obsolete, we only support minimum functionality.

Parameters

bus	I2C bus to use
addr	The I2C address of the device

Returns

The device context, or NULL if an error occurred

Exceptions

std::runtime_error

on failure.

~LSM303D

(

)

LSM303D Destructor

Here is the call graph for this function:

Member Function Documentation

void update

(

void

)

Update the internal stored values from sensor data. This method must be called before querying the acceleration, magnetometer, or temperature.

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

void getMagnetometer	(	float *	x,
		float *	y,
		float *	z
	)

Return magnetometer data in micro-Teslas (uT). update() must have been called prior to calling this method.

Parameters

x	Pointer to a floating point value that will have the current x component placed into it
y	Pointer to a floating point value that will have the current y component placed into it
z	Pointer to a floating point value that will have the current z component placed into it

Here is the call graph for this function:

std::vector< float > getMagnetometer

(

)

Return magnetometer data in micro-Teslas (uT) in the form of a floating point vector. update() must have been called prior to calling this method.

Returns

A floating point vector containing x, y, and z in that order

void getAccelerometer	(	float *	x,
		float *	y,
		float *	z
	)

Return acceleration data in gravities. update() must have been called prior to calling this method.

Parameters

x	Pointer to a floating point value that will have the current x component placed into it
y	Pointer to a floating point value that will have the current y component placed into it
z	Pointer to a floating point value that will have the current z component placed into it

Here is the call graph for this function:

std::vector< float > getAccelerometer

(

)

Return acceleration data in gravities in the form of a floating point vector. update() must have been called prior to calling this method.

Returns

A floating point vector containing x, y, and z in that order

float getTemperature

(

void

)

Return temperature data in degrees Celsius. NOTE: This is not the ambient room temperature. update() must have been called prior to calling this method.

Returns

Temperature in degrees Celsius

Here is the call graph for this function:

void init

(

LSM303D_M_RES_T

res

)

Initialize the device and start operation. This function is called from the constructor so it will not typically need to be called by a user unless the device is reset. It will initialize the accelerometer and magnetometer (if enabled) to certain default running modes.

Parameters

res	One of the LSM303D_M_RES_T values. This value sets the resolution of the magnetometer. At init time, this value is set to LSM303D_M_RES_HIGH.

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

void setAccelerometerFullScale

(

LSM303D_AFS_T

fs

)

Set the full scale (sensitivity) value for the accelerometer. This device supports 2G, 4G, 6G, 8G, and 16G full scale modes.

Parameters

fs	One of the LSM303D_AFS_T values

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

void setMagnetometerFullScale

(

LSM303D_MFS_T

fs

)

Set the full scale (sensitivity) value for the magnetometer. This device supports 2, 4, 8, and 16 Gauss full scale modes.

Parameters

fs	One of the LSM303D_MFS_T values

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

void setAccelerometerODR

(

LSM303D_AODR_T

odr

)

Set the accelerometer output data rate (ODR)

Parameters

odr	One of the LSM303D_AODR_T values. The default set at initialization time is LSM303D_AODR_100HZ.

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

void setMagnetometerODR

(

LSM303D_MODR_T

odr

)

Set the magnetometer output data rate (ODR)

Parameters

odr	One of the LSM303D_MODR_T values. The default set at initialization time is LSM303D_MODR_12_5HZ.

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

uint8_t readReg ( uint8_t  reg )

protected

Read a register

Parameters

reg	The register to read

Returns

The value of the register

Here is the call graph for this function:

int readRegs ( uint8_t  reg, uint8_t *  buffer, int  len  )

protected

Read contiguous registers into a buffer

Parameters

buffer	The buffer to store the results
len	The number of registers to read

Returns

The number of bytes read

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

void writeReg ( uint8_t  reg, uint8_t  val  )

protected

Write to a register

Parameters

reg	The register to write to
val	The value to write

Exceptions

std::runtime_error

on failure

Here is the call graph for this function:

Collaboration diagram for LSM303D:

---

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

• src/lsm303d/lsm303d.hpp
• src/lsm303d/lsm303d.cxx