enableSPI

Enable SPI interface

Description

example

enableSPI(mypi) enables the SPI bus and makes the GPIO pins available for use as SPI pins. By default, SPI is enabled.

For example, on a Raspberry Pi™ Model B Rev 2 board, enabling the SPI bus makes GPIO 10 (SPI0_MOSI), GPIO 9 (SPI0_MISO), and GPIO 11 (SPI0_SCLK) available for use as SPI pins.

To disable SPI, use disableSPI.

Examples

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You can connect to and exchange data with an SPI device.

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

mypi = raspi
r = 

  raspi with properties:

         DeviceAddress: '172.18.188.249'              
                  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'}                     
      AvailableWebcams: {}                            
           I2CBusSpeed: 100000                        

  Supported peripherals

By default, SPI is enabled. If SPI is disabled, AvailableSPIChannels does not show any channels.

Enable SPI and get the channels by using enableSPI.

enableSPI(mypi)
mypi.AvailableSPIChannels
ans = 

    'CE0'    'CE1'

Show the location of the SPI pins, GPIO 10 (SPI0_MOSI), GPIO 9 (SPI0_MISO), and GPIO 11 (SPI0_SCLK), on the GPIO header.

showPins(mypi)

After physically connecting your SPI device to the three SPI pins, connect to the SPI device.

myspidevice = spidev(mypi,'CE1',0)
myspidevice = 

Spidev with Properties:
           Channel: 'CE1'
              Mode: 0 
       BitsPerWord: 8
             Speed: 500000

Write data to, and read data from, the SPI device.

out = writeRead(myspidevice,[hex2dec('08') hex2dec('D4')])
out = 
         7 211

If you are not using SPI, disable SPI to make additional GPIO pins available.

disableSPI(mypi)

Input Arguments

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Connection to a specific Raspberry Pi hardware board, specified as a raspi object.