lis3dh
Add-On Required: This feature requires the MATLAB Support Package for Arduino Hardware add-on.
Description
The lis3dh object reads linear acceleration and temperature using
the LIS3DH sensor connected to the I2C bus of the Arduino® hardware. Attach the LIS3DH sensor to the I2C pins on the hardware. You can read
the data from the sensor in MATLAB® using the Object Functions.
Creation
Description
accelSensor = lis3dh(a)
Example:
accelSensor = lis3dh(a);.
accelSensor = lis3dh(a,Name,Value)Name,Value
pair arguments.
Example:
accelSensor = lis3dh(a,'I2CAddress',0x19);.
Input Arguments
Name-Value Arguments
Properties
Note
All the properties except
SamplesReadandSamplesAvailablecan be set by specifying as name-value pair arguments while creating anlis3dhobject.The properties
I2CAddressandBusare immutable (the property value is set during construction; you cannot change the value of an immutable property after the object is created).The
TimeFormatproperty is tunable, which means you can change the value anytime. TheSampleRate,SamplesPerRead,ReadMode, andOutputFormatproperties are non-tunable, which means you cannot change their values once the object is locked. Objects are locked when you call thereadfunction, and thereleasefunction unlocks them. If a property is tunable, you can change its value at any time.
Specify the I2C address of the sensors when multiple I2C devices with the expected address for LIS3DH are connected to the same hardware board. LIS3DH can have two I2C addresses depending on the logic level on pin SA0 of the sensor.
| Pin Name | Pin State | I2C Address |
|---|---|---|
| SA0 | Low | 0x18 |
| High | 0x19 |
You can specify the I2C address in:
Hexadecimal, decimal, or binary format
String of hexadecimal value of I2C Address
Character vector of hexadecimal value of I2C Address
0x18 is the I2C address of the LIS3DH connected to Arduino board.
If not specified, the object will be created with one of the available I2C device
address in the table. Availability of I2C device with the expected address will be
determined by using scanI2CBus.
I2C bus number, specified as 0 or 1. The default value is 0.
Data Types: double
The rate in samples/s at which data is read from the sensor.
Data Types: double
Number of samples read from the sensor in a single execution of the
read function.
Data Types: double
Specify whether to return the latest or the oldest data samples. The number of
samples depends on the SamplesPerRead value. The data read from the
sensor is stored in the MATLAB buffer.
latest—Provides the latest data samples available in the buffer. All previous data samples in the buffer are discarded. For example, if
SamplesPerRead= 3, the latest three data samples read by the sensor are returned.The following figure illustrates how latest data samples are returned assuming S1 is the first sensor data stored in the buffer, S2 is the second data and so on and Sn is the last data stored in the buffer and
SamplesPerReadproperty is set to 3 during sensor object creation.
oldest—Provides the oldest data samples available in the buffer. In this case, no data samples are discarded. For example, if
SamplesPerRead= 3, the first three data samples read are returned for the first read, the next three data samples are returned for the second read, and so on.The following figure illustrates how oldest data samples are returned assuming S1 is the first sensor data stored in the buffer, S2 is the second data and so on and Sn is the last data stored in the buffer and
SamplesPerReadproperty is set to 3 during sensor object creation.
Data Types: character vector | string
This property is read-only.
Samplesread property outputs the values of samples read so far by
executing read function. Samplesread is set to
0, when the object is created or when you
release the object.
Data Types: double
Set the output format of the data returned by executing the
read function.
When the OutputFormat is set to timetable,
the data returned has the following fields:
Time — Time stamps in
datetimeordurationformatAcceleration — N-by-3 array in units of m/s2
Temperature — Temperature in units of celsius
When the OutputFormat is set to matrix, the
data is returned as matrices of pressure, temperature, and time stamps. The units for
the sensor readings are the same as the timetable format.
N is the number of samples per read specified by
SamplesPerRead. The three columns of each field represent the
measurements in x, y, and z axes.
Data Types: character vector | string
Set the format of the time displayed when the sensor data is read.
datetime— Displays the date and time at which the data is read.duration— Displays the time elapsed in seconds after the sensor object is locked. The sensor object gets locked at the first call of thereadfunction either after the object creation or after the execution of thereleasefunction.
Data Types: character vector | string
Object Functions
readAcceleration | Read one sample of acceleration from sensor |
readTemperature | Read one sample of temperature from sensor |
readVoltage | Read voltage from ADC pins on sensor |
read | Read real-time sensor data at a specified rate |
release | Release the sensor object |
flush | Flush the host buffer |
info | Read information related to sensor |
Examples
Create Connection to LIS3DH Sensor
Create an arduino object with the I2C library.
a = arduino('COM4', 'Uno', 'Libraries', 'I2C');
Create the sensor object.
accelSensor = lis3dh(a)
accelSensor =
lis3dh with properties:
I2CAddress: 24 ("0x18")
Bus: 0
SCLPin: "A5"
SDAPin: "A4"
SampleRate: 100 (Samples/s)
SamplesPerRead: 10
ReadMode: 'latest'
SamplesRead: 0
SamplesAvailable: 0
Show all properties, functions
Create LIS3DH Sensor Connection with Additional Name-Value Pair Arguments
Create a sensor object with additional properties specified as name-value pair arguments.
clear accelSensor; accelSensor = lis3dh(a,'SampleRate',50,'SamplesPerRead',5,'ReadMode','oldest')
accelSensor =
lis3dh with properties:
I2CAddress: 24 ("0x18")
Bus: 0
SCLPin: "A5"
SDAPin: "A4"
SampleRate: 100 (samples/s)
SamplesPerRead: 10
ReadMode: "oldest"
SamplesRead: 0
SamplesAvailable: 0
Show all properties all functionsMore About
Version History
Introduced in R2022b
