lsm303c

Connect LSM303C sensor on Raspberry Pi hardware I2C bus

Since R2021a

Description

The lsm303c object reads ambient temperature, linear acceleration and magnetic field along the X, Y, and Z axes using the STMicroelectronics^® I2C-based LSM303C inertial measurement unit (IMU) sensor interfaced with the Raspberry Pi^® hardware. Before you use the lsm303c object, ensure that the I2C interface is enabled on your Raspberry Pi kernel. You can then create a connection to the Raspberry Pi board using the raspi object and set its properties. For more information, see raspi.

Creation

Syntax

sensor = lsm303c(mypi)

sensor = lsm303c(mypi,Name,Value)

Description

sensor = lsm303c(mypi) creates a LSM303C sensor object with default property values. The object represents a connection to the sensor on the Raspberry Pi hardware mypi.

sensor = lsm303c(mypi,Name,Value) creates a LSM303C sensor object with properties using one or more Name,Value arguments.

Input Arguments

mypi — Raspberry Pi hardware connection

raspi object

Raspberry Pi hardware board connection specified as a raspi object.

Example: sensor = lsm303c(mypi) creates a connection to the LSM303C sensor on the Raspberry Pi object mypi.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Bus — I2C bus address of Raspberry Pi board

'i2c-0' | 'i2c-1'

I2C bus address of the Raspberry Pi hardware board.

Example: sensor = lsm303c(mypi, 'Bus', 'i2c-1') creates the sensor object on the 'i2c-1' bus of the Raspberry Pi board.

Data Types: char

Object Functions

readAcceleration	Read one sample of acceleration from sensor
readTemperature	Read one sample of temperature from sensor
readMagneticField	Read one sample of magnetic field from sensor

Examples

Create LSM303C Sensor Connection

Ensure that the I2C interface on the Raspberry Pi kernel is enabled and then create an lsm303c sensor object.

You can enable the I2C interface using:

• Raspberry Pi Kernel I2C Interfacing options on Linux terminal. For more information, see Enable I2C Interface on Raspberry Pi Hardware Kernel or

• Raspberry Pi Resource Monitor App. For more information, see Enabling External Peripherals on Raspberry Pi Hardware Kernel.

Create a connection from MATLAB^® to the Raspberry Pi hardware board.

mypi = raspi('raspberrypi-hysdu8X38o','rocky','bullwinkle')

mypi = 

  Raspi with Properties:

           DeviceAddress: 'raspberrypi-hysdu8X38o'
                    Port: 18734
               BoardName: 'Raspberry Pi 3 Model B+'
           AvailableLEDs: {'led0'}
    AvailableDigitalPins: [4,5,6,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27]
    AvailableSPIChannels: {‘CE0’,’CE1’}
       AvailableI2CBuses: {'i2c-1'}
             I2CBusSpeed: 100000
        AvailabelWebCams: mmal service 16.1 (platform:bcm2835-v4l2)

GPIO header pins I2C_SDA (GPIO 2) and I2C_SCL (GPIO 3) are used for I2C functionality. Display pin mapping of the Raspberry Pi hardware board.

showPins(mypi);

Get the addresses of the LSM303C sensor connected to the I2C bus 'i2c-1'.

sensor = scanI2CBus(mypi,'i2c-1');

ans =

  1×2 cell array

    {'0x1D'}    {'0x1E'}

Create an lsm303c sensor object on the I2C bus 'i2c-1' on addresses '0x1D' and '0x1E'.

sensor = lsm303c(mypi,'Bus','i2c-1');

sensor = 

  lsm303c with properties:

                         I2CAddress: 29 ("0x1D")
                                   : 30 ("0x1E")
                                Bus: i2c-1

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

• Timestamp value is always returned in seconds.

Version History

Introduced in R2021a