UPM

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LIS3DH Class

Module: lis3dh

The LIS3DH is an ultra-low-power high performance three-axis linear accelerometer belonging to the "nano" family which leverages on the robust and mature manufacturing processes already used for the production of micromachined accelerometers.
The LIS3DH has user-selectable full scales of 2g/4g/8g/16g and is capable of measuring accelerations with output data rates from 1 Hz to 5300 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.

Methods

LIS3DH

(
  • bus
  • addr
  • cs
)
Number

LIS3DH 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 Number

    I2C or SPI bus to use

  • addr Number

    The address for this device. -1 for SPI

  • cs Number

    The gpio pin to use for the SPI Chip Select. -1 for I2C or for SPI with a hardware controlled pin.

Returns:

Number:

init

(
  • odr
  • fs
  • high_res
)

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 LIS3DH_ODR_T

    One of the LIS3DH_ODR_T values. The default is LIS3DH_ODR_100HZ

  • fs LIS3DH_FS_T

    One of the LIS3DH_FS_T values. The default is LIS3DH_FS_2G

  • high_res Boolean

    true to enable high resolution mode, false to disable. The default is true.

enableAxes

(
  • x_axis_enable
  • y_axis_enable
  • z_axis_enable
)

Enable or disable specific axes. init() enables all three by default.

Parameters:

  • x_axis_enable Boolean

    true to enable X axis, false to disable

  • y_axis_enable Boolean

    true to enable Y axis, false to disable

  • z_axis_enable Boolean

    true to enable Z axis, false to disable

enableBDUMode

(
  • bdu_enable
)

Enable or disable Block Data Update (BDU) mode.

Parameters:

  • bdu_enable Boolean

    true to enable BDU mode, false to disable

enableLPMode

(
  • lp_enable
)

Enable or disable Low Power (LP) mode. Checks if mutually exclusive High Resolution (HR) mode is enabled and bails out if yes.

Parameters:

  • lp_enable Boolean

    true to enable LP mode, false to disable

enableHRMode

(
  • hr_enable
)

Enable or disable High Resolution (HR) mode. Checks if mutually exclusive Low Power (LP) mode is enabled and bails out if yes.

Parameters:

  • hr_enable Boolean

    true to enable HR mode, false to disable

enableNormalMode

()

Enable Normal mode by explicitly disabling LP and HR ones. Note that there's no "disable" part as it's generally unknown, which mode we were in previously. To get out of Normal mode, just enable HR or LP one.

enableHPFiltering

(
  • filter
)

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

Parameters:

  • filter Boolean

    true to enable filtering, false to disable

enableInterruptLatching

(
  • int1_latch
  • int2_latch
)

Enable or disable interrupt latching for INT1 and INT2. See the datasheet for details.

Parameters:

  • int1_latch Boolean

    true to enable latching for INT1, false to disable

  • int2_latch Boolean

    true to enable latching for INT2, false to disable

enableADC

(
  • adc_enable
)

Enable or disable built-in Analog-to-Digital Converter (ADC).

Parameters:

  • adc_enable Boolean

    true to enable ADC, false to disable

enableTemperature

(
  • temperature_enable
)

Enable or disable built-in temperature sensor. It depends on ADC being enabled, so we enable it unconditionally. See datasheet for details.

Parameters:

  • temperature_enable Boolean

    true to enable temp sensor, false to disable

setODR

(
  • odr
)

Set the output data rate (ODR) of the device

Parameters:

  • odr LIS3DH_ODR_T

    One of the LIS3DH_ODR_T values

setFullScale

(
  • fs
)

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

Parameters:

  • fs LIS3DH_FS_T

    One of the LIS3DH_FS_T values

setInterruptActiveHigh

(
  • high
)

Indicate whether INT1 and INT2 interrupts should be active high (default) or active low. See the datasheet for details.

Parameters:

  • high Boolean

    true for active high, false for active low

setInt1Config

(
  • cfg
)

Set interrupt 1 configuration. See the datasheet for details.

Parameters:

  • cfg Number

    A bitmask of values from LIS3DH_CTRL_REG3_BITS_T

setInt2Config

(
  • cfg
)

Set interrupt 2 configuration. See the datasheet for details.

Parameters:

  • cfg Number

    A bitmask of values from LIS3DH_CTRL_REG6_BITS_T

readReg

(
  • reg
)
Number

Read a register

Parameters:

  • reg Number

    The register to read

Returns:

Number:

The value of the register

readRegs

(
  • reg
  • buffer
  • len
)
Number

Read contiguous registers into a buffer

Parameters:

  • reg Number

    The register to start the read from

  • buffer Uint8_t *

    The buffer to store the results

  • len Number

    The number of registers to read

Returns:

Number:

The number of bytes read

writeReg

(
  • reg
  • val
)

Write to a register

Parameters:

  • reg Number

    The register to write to

  • val Number

    The value to write

update

()

Update the internal stored values from sensor data

getChipID

() Number

Return the chip ID

Returns:

Number:

The chip ID

getAccelerometer

(
  • x
  • y
  • z
)

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

Parameters:

  • x Float *

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

  • y Float *

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

  • z Float *

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

getAccelerometer

() Std::vector float

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

Returns:

Std::vector float :

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

getTemperature

(
  • fahrenheit
)
Number

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

Parameters:

  • fahrenheit Boolean

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

Returns:

Number:

The temperature in degrees Celsius or Fahrenheit

getStatus

() Number

Return the contents of the status register

Returns:

Number:

A bitmask of values from LIS3DH_STATUS_REG_BITS_T

getStatusAux

() Number

Return the contents of the status aux register

Returns:

Number:

A bitmask of values from LIS3DH_STATUS_REG_AUX_BITS_T

installISR

(
  • intr
  • gpio
  • level
  • isr
  • arg
)

Install an interrupt handler

Parameters:

  • intr LIS3DH_INTERRUPT_PINS_T

    One of the LIS3DH_INTERRUPT_PINS_T values specifying which interrupt pin you are installing

  • gpio Number

    GPIO pin to use as interrupt pin

  • level Mraa::Edge

    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 Function

    The interrupt handler, accepting a void * argument

  • arg Void *

    The argument to pass the the interrupt handler

uninstallISR

(
  • intr
)

Uninstall a previously installed interrupt handler

Parameters:

  • intr LIS3DH_INTERRUPT_PINS_T

    One of the LIS3DH_INTERRUPT_PINS_T values, specifying which interrupt pin you are removing