Configuring I2C Communication

You need to have either a Total Phase Aardvark host adapter or a NI USB-845x adapter board installed to use the i2c interface. The following sections describe configuration for each option.

Configuring Total Phase Aardvark

To use the I2C interface with the Aardvark adapter, you must download the Hardware Support Package to obtain the necessary files. You must also download the USB device driver from the vendor.

If you do not have the Aardvark driver installed, see Install the Total Phase Aardvark I2C/SPI Interface Support Package.

The aardvark.dll file that comes with the Total Phase Aardvark adapter board must be available in one of the following locations for use on Windows^® platforms.

• The location where MATLAB was started from (Bin folder).

• The MATLAB current folder (PWD).

• The Windows folder C:\winnt or C:\windows.

• The folders listed in the PATH environment variable.

Ensure that the Aardvark adapter is installed properly.

instrhwinfo('i2c')

ans = 

  HardwareInfo with properties:

    InstalledAdaptors: {'Aardvark'  'NI845x'}
       JarFileVersion: 'Version 4.1'

Access to your hardware may be provided by a support package. Go to the Support Package Installer to learn more.

Look at the adapter properties.

instrhwinfo('i2c','Aardvark')

ans = 

  HardwareInfo with properties:

             AdaptorDllName: 'C:\Program Files\MATLAB\R2019b\toolbox\instrument\instrumentadaptors\win64\mwaardvarki2c.dll'
          AdaptorDllVersion: 'Version 4.1'
                AdaptorName: 'Aardvark'
              BoardIdsInUse: [1×0 double]
          InstalledBoardIDs: 0
       DetectedBoardSerials: {'2237482577 (BoardIndex: 0)'}
      ObjectConstructorName: 'i2c('Aardvark', BoardIndex, RemoteAddress);'
              VendorDllName: 'aardvark.dll'
    VendorDriverDescription: 'Total Phase I2C Driver'

Access to your hardware may be provided by a support package. Go to the Support Package Installer to learn more.

You can create an I2C object using the i2c function. The example in the next section uses an I2C object called eeprom that communicates to an EEPROM chip. View the properties after creating the object.

eeprom = i2c('aardvark',0,'50h')

   I2C Object : I2C-0-50h

   Communication Settings 
      BoardIndex          0
      BoardSerial         2237482577
      BitRate:            100 kHz
      RemoteAddress:      50h
      Vendor:             aardvark


   Communication State 
      Status:             closed
      RecordStatus:       off

   Read/Write State  
      TransferStatus:     idle

You can see that the communication settings properties reflect what was used to create the object – BoardIndex of 0 and RemoteAddress of 50h. For information about other properties, see Properties.

Configuring NI USB-845x

To use the I2C interface with the NI USB-845x adapter, you must download the Hardware Support Package to obtain the latest driver, if you do not already have the driver installed. If you already have the latest driver installed, you do not need to download this Support Package.

If you do not have the NI USB-845x driver installed, see Install the NI-845x I2C/SPI Interface Support Package.

Ensure that the NI USB-845x adapter is installed properly.

instrhwinfo('i2c')

ans = 

  HardwareInfo with properties:

    InstalledAdaptors: {'Aardvark'  'NI845x'}
       JarFileVersion: 'Version 4.1'

Access to your hardware may be provided by a support package. Go to the Support Package Installer to learn more.

Look at the NI USB-845x adapter properties.

instrhwinfo('i2c','NI845x')

ans = 

  HardwareInfo with properties:

             AdaptorDllName: 'C:\Program Files\MATLAB\R2019b\toolbox\instrument\instrumentadaptors\win64\mwni845xi2c.dll'
          AdaptorDllVersion: 'Version 4.1'
                AdaptorName: 'NI845x'
              BoardIdsInUse: [1×0 double]
          InstalledBoardIDs: [1×0 double]
       DetectedBoardSerials: {0×1 cell}
      ObjectConstructorName: 'i2c('NI845x', BoardIndex, RemoteAddress);'
              VendorDllName: 'Ni845x.dll'
    VendorDriverDescription: 'National Instruments NI USB 845x Driver'

Access to your hardware may be provided by a support package. Go to the Support Package Installer to learn more.

You can create an I2C object using the i2c function. View the properties after creating the object.

i2cobj = i2c('NI845x',0,'10h')

   I2C Object : I2C-0-10h

   Communication Settings 
      BoardIndex          0
      BoardSerial         0
      BitRate:            100 kHz
      RemoteAddress:      10h
      Vendor:             NI845x


   Communication State 
      Status:             closed
      RecordStatus:       off

   Read/Write State  
      TransferStatus:     idle

You can see that the communication settings properties reflect what was used to create the object – BoardIndex of 0 and RemoteAddress of 10h. For information about other properties, see Properties.