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bmp280

Connect BMP280 sensor on Raspberry Pi hardware I2C bus

Since R2023a

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Add-On Required: This feature requires the MATLAB Support Package for Raspberry Pi Hardware add-on.

Description

The bmp280 object reads barometric air pressure and ambient temperature using the BMP280 sensor.

The bmp280 object represents a connection to the sensor on the Raspberry Pi® hardware I2C bus. Attach an BMP280 sensor to the I2C pins on the Raspberry Pi hardware. You can read the data from your sensor in MATLAB®using the object functions.

Before you use the bmp280 object, create an Raspberry Pi object using raspi and set its properties as mentioned in raspi.

Creation

Syntax

pressureSensor = bmp280(mypi)
pressureSensor = bmp280(mypi,Name,Value)

Description

pressureSensor = bmp280(mypi) creates a sensor object with default property values. The object represents the connection to the sensor on the Raspberry Pi hardware, mypi.

pressureSensor = bmp280(mypi,Name,Value) creates a sensor object with properties using one or more Name,Value pair arguments.

Example: pressureSensor = bmp280(mypi) creates a connection to the BMP280 sensor on the Raspberry Pi hardware represented as an object, mypi.

Input Arguments

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Raspberry Pi hardware connection created using raspi, specified as an object.

Example: pressureSensor = bmp280(mypi) creates a connection to the BMP280 sensor on the Raspberry Pi hardware represented as an 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.

I2C bus address of the Raspberry Pi hardware board.

Example: sensor = bmp280(mypi, 'Bus', 'i2c-1') creates the sensor object on the 'i2c-1' bus of the Raspberry Pi board.

Data Types: char

Specify the I2C address of the sensors when multiple I2C devices with the expected address for BMP280 are connected to the same hardware board. BMP280 can have two I2C addresses depending on the logic level on pin SDO of the sensor.

Pin NamePin StateI2C Address
SDOLow0x76
High0x77

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

Example: pressureSensor = bmp280(mypi,'I2CAddress','0x76')

0x76 is the I2C address of the BMP280 connected to Raspberry Pi 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.

Usage

Create Connection to BMP280 Sensor

Ensure that the I2C interface on the Raspberry Pi kernel is enabled and then create an bmp280 sensor object.

You can enable the I2C interface using:

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)

Get the addresses of the BMP280 sensor connected to the I2C bus 'i2c-1'.

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

  1×1 cell array
 

    {'0x77'}

Create an bmp280 sensor object on the I2C bus 'i2c-1' on address '0x77'.

sensor = bmp280(mypi,'Bus','i2c-1','I2CAddress','0x77');
sensor = 

  bmp280 with properties:

                         I2CAddress: 105  ("0x77")
                                Bus: i2c-1

Object Functions

readTemperatureRead one sample of temperature from sensor
readPressureRead one absolute pressure data sample from sensor

Version History

Introduced in R2023a

See Also

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