LIS2DS12 Class Reference

API for the LIS2DS12 3-axis Accelerometer. More...

Detailed Description

• ID: lis2ds12
• Name: Digital 3-axis Accelerometer
• Category: accelerometer
• Manufacturer: stmicro
• Connection: i2c spi gpio
• Link: http://www.st.com/en/mems-and-sensors/lis2ds12.html

The LIS2DS12 is an ultra-low-power high performance three-axis linear accelerometer belonging to the "pico" family which leverages on the robust and mature manufacturing processes already used for the production of micromachined accelerometers.

The LIS2DS12 has user-selectable full scales of 2g/4g/8g/16g and is capable of measuring accelerations with output data rates from 1 Hz to 6400 Hz.

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 both I2C (default) and SPI operation.

This device requires 1.8v operation.

    // Instantiate an LIS2DS12 using default I2C parameters
    upm::LIS2DS12 sensor;

    // For SPI, bus 0, you would pass -1 as the address, and a valid pin
    // for CS: LIS2DS12(0, -1, 10);

    // 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;

        // we show both C and F for temperature
        cout << "Compensation Temperature: " << sensor.getTemperature() << " C / "
             << sensor.getTemperature(true) << " F" << endl;

        cout << endl;

        upm_delay_us(250000);
    }

Public Member Functions
	LIS2DS12 (int bus=LIS2DS12_DEFAULT_I2C_BUS, int addr=LIS2DS12_DEFAULT_I2C_ADDR, int cs=-1)
virtual	~LIS2DS12 ()
void	update ()
uint8_t	getChipID ()
void	getAccelerometer (float *x, float *y, float *z)
std::vector< float >	getAccelerometer ()
float	getTemperature (bool fahrenheit=false)
void	init (LIS2DS12_ODR_T odr=LIS2DS12_ODR_100HZ, LIS2DS12_FS_T fs=LIS2DS12_FS_2G)
void	reset ()
void	setODR (LIS2DS12_ODR_T odr)
void	setFullScale (LIS2DS12_FS_T fs)
void	enableHPFiltering (bool filter)
void	enableInterruptLatching (bool latch)
void	setInterruptActiveHigh (bool high)
void	setInterruptPushPull (bool pp)
void	setInt1Config (uint8_t cfg)
void	setInt2Config (uint8_t cfg)
uint8_t	getStatus ()
void	installISR (LIS2DS12_INTERRUPT_PINS_T intr, int gpio, mraa::Edge level, void(*isr)(void *), void *arg)
void	uninstallISR (LIS2DS12_INTERRUPT_PINS_T intr)
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
lis2ds12_context	m_lis2ds12

Constructor & Destructor Documentation

LIS2DS12	(	int	bus = LIS2DS12_DEFAULT_I2C_BUS,
		int	addr = LIS2DS12_DEFAULT_I2C_ADDR,
		int	cs = -1
	)

LIS2DS12 constructor.

This device can support both I2C and SPI. For SPI, set the addr to -1, and specify a positive integer representing the Chip Select (CS) pin for the cs argument. If you are using a hardware CS pin (like edison with arduino breakout), then you can connect the proper pin to the hardware CS pin on your MCU and supply -1 for cs. The default operating mode is I2C.

Parameters

bus	I2C or SPI bus to use
addr	The address for this device. -1 for SPI
cs	The gpio pin to use for the SPI Chip Select. -1 for I2C or for SPI with a hardware controlled pin.

Exceptions

std::runtime_error

on initialization failure

~LIS2DS12 ( )

virtual

LIS2DS12 destructor

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Member Function Documentation

void update

(

void

)

Update the internal stored values from sensor data

Exceptions

std::runtime_error

on failure

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uint8_t getChipID

(

)

Return the chip ID

Returns

The chip ID

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

Return accelerometer 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

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std::vector< float > getAccelerometer

(

)

Return accelerometer 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

(

bool

fahrenheit = false

)

Return the current measured temperature. Note, this is not ambient temperature. update() must have been called prior to calling this method.

Parameters

fahrenheit

true to return data in Fahrenheit, false for Celicus. Celsius is the default.

Returns

The temperature in degrees Celsius or Fahrenheit

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void init	(	LIS2DS12_ODR_T	odr = LIS2DS12_ODR_100HZ,
		LIS2DS12_FS_T	fs = LIS2DS12_FS_2G
	)

Initialize the device and start operation. This function is called from the constructor so will not typically need to be called by a user unless the device is reset.

Parameters

odr	One of the LIS2DS12_ODR_T values. The default is LIS2DS12_ODR_100HZ
fs	One of the LIS2DS12_FS_T values. The default is LIS2DS12_FS_2G

Exceptions

std::runtime_error

on failure

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void reset

(

)

Reset the device as if during a power on reset. All configured values are lost when this happens. You should call init() afterwards, or at least perform the same initialization init() does before continuing.

Exceptions

std::runtime_error

on failure

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void setODR

(

LIS2DS12_ODR_T

odr

)

Set the output data rate (ODR) of the device

Parameters

odr	One of the LIS2DS12_ODR_T values

Exceptions

std::runtime_error

on failure

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void setFullScale

(

LIS2DS12_FS_T

fs

)

Set the full scale (FS) of the device. This device supports a full scale of 2, 4, 8, and 16G.

Parameters

fs	One of the LIS2DS12_FS_T values

Exceptions

std::runtime_error

on failure

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void enableHPFiltering

(

bool

filter

)

Enable high pass filtering of the accelerometer axis data. init() disables this by default. See the datasheet for details.

Parameters

filter

true to enable filtering, false to disable

Exceptions

std::runtime_error

on failure

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void enableInterruptLatching

(

bool

latch

)

Enable or disable interrupt latching. If latching is disabled, pulsed is enabled. See the datasheet for details.

Parameters

latch

true to enable latching, false to disable

Exceptions

std::runtime_error

on failure

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void setInterruptActiveHigh

(

bool

high

)

Indicate whether the interrupt should be active high (default) or active low. See the datasheet for details.

Parameters

high	true for active high, false for active low

Exceptions

std::runtime_error

on failure

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void setInterruptPushPull

(

bool

pp

)

Indicate whether interrupts are push-pull (default) or open drain. See the datasheet for details.

Parameters

pp	true for push-pull, false for open-drain

Exceptions

std::runtime_error

on failure

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void setInt1Config

(

uint8_t

cfg

)

Set interrupt 1 configuration. See the datasheet for details.

Parameters

cfg	A bitmask of values from LIS2DS12_CTRL4_BITS_T

Exceptions

std::runtime_error

on failure

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void setInt2Config

(

uint8_t

cfg

)

Set interrupt 2 configuration. See the datasheet for details.

Parameters

cfg	A bitmask of values from LIS2DS12_CTRL5_BITS_T

Exceptions

std::runtime_error

on failure

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uint8_t getStatus

(

)

Return the contents of the status register

Returns

A bitmask of values from LIS2DS12_STATUS_BITS_T

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void installISR	(	LIS2DS12_INTERRUPT_PINS_T	intr,
		int	gpio,
		mraa::Edge	level,
		void(*)(void *)	isr,
		void *	arg
	)

install an interrupt handler

Parameters

intr	One of the LIS2DS12_INTERRUPT_PINS_T values specifying which interrupt pin you are installing
gpio	GPIO pin to use as interrupt pin
level	The interrupt trigger level (one of mraa::Edge values). Make sure that you have configured the interrupt pin properly for whatever level you choose.
isr	The interrupt handler, accepting a void * argument
arg	The argument to pass the the interrupt handler

Exceptions

std::runtime_error

on failure

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void uninstallISR

(

LIS2DS12_INTERRUPT_PINS_T

intr

)

uninstall a previously installed interrupt handler

Parameters

intr	One of the LIS2DS12_INTERRUPT_PINS_T values specifying which interrupt pin you are removing

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uint8_t readReg

(

uint8_t

reg

)

Read a register

Parameters

reg	The register to read

Returns

The value of the register

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

Read contiguous registers into a buffer

Parameters

reg	The register to start the read from
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

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void writeReg	(	uint8_t	reg,
		uint8_t	val
	)

Write to a register

Parameters

reg	The register to write to
val	The value to write

Exceptions

std::runtime_error

on failure

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Collaboration diagram for LIS2DS12:

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

• src/lis2ds12/lis2ds12.hpp
• src/lis2ds12/lis2ds12.cxx