# MATLAB/Octave - API Bindings¶

The MATLAB/Octave bindings allow you to control Bricks and Bricklets from your MATLAB/Octave scripts. The ZIP file for the bindings contains:

• matlab/Tinkerforge.jar, a precompiled Java library for MATLAB
• in matlab/source/ the source code of Tinkerforge.jar for MATLAB
• in matlab/examples/ the MATLAB examples for every Brick and Bricklet
• octave/Tinkerforge.jar, a precompiled Java library for Octave
• in octave/source/ the source code of Tinkerforge.jar for Octave
• in octave/examples/ the Octave examples for every Brick and Bricklet

The MATLAB/Octave bindings are based on the Java bindings.

## Requirements¶

• MATLAB or Octave 3.6 with Java support

## Installation¶

Before you and use the bindings with MATLAB or Octave you have to install them.

### MATLAB¶

The Java support in MATLAB is typically enabled by default. You can test this with the following command in MATLAB:

version -java


If this command doesn't show Java support then see the MATLAB documentation about how to configure Java for MATLAB.

To use the bindings MATLAB needs to know where to find the Tinkerforge.jar file. There are several ways to archive this, see the MATLAB documentation for more details on all of them. The recommended way is to the add the bindings to the preferences folder.

Start MATLAB and run the following command to get the path of the preferences folder:

prefdir(1)


Preferences folder path examples:

• Windows: C:\Users\<user>\AppData\local\MathWorks\MATLAB\R2016a
• Linux: /home/<user>/.matlab/R2016a
• macOS: /Users/<user>/.matlab/R2016a

Copy the Tinkerforge.jar file from the matlab/ folder to the preferences folder. Then the Tinkerforge.jar file has to be added to MATLAB's class path. Edit or create a file named javaclasspath.txt in the preferences folder and add the absolute path to the Tinkerforge.jar file as a new line to it. For example:

• Windows: C:\Users\<user>\AppData\local\MathWorks\MATLAB\R2016a\Tinkerforge.jar
• Linux: /home/<user>/.matlab/R2016a/Tinkerforge.jar
• macOS: /Users/<user>/.matlab/R2016a/Tinkerforge.jar

Restart MATLAB and run the following command, it should list the Tinkerforge.jar file:

javaclasspath


The bindings are now ready to use.

### Octave¶

If Java support is available in Octave depends on the Octave version. Until version 3.6 (inclusive) Java support was in a separate module. Since version 3.8 it is available by default.

But in Octave 3.8 callbacks don't work, see the known problems section. We recommend Octave 3.6 for now.

On Linux you have to install an extra package for the Java support in Octave 3.6:

sudo apt-get install octave octave-java


For Windows we recommend the MinGW build of Octave, because it comes with Java support by default. The Octave Wiki has a guide about how to set up Octave for Windows.

You can test if Java support is available with the following command in Octave:

octave_config_info("features").JAVA


To make the bindings available in Octave the Tinkerforge.jar from the octave/ folder has to be added to Octave's class path. This can be done with the following Octave command on Windows:

javaaddpath("C:\\Absolute\\path\\to\\Octave\\Tinkerforge.jar");


Or by this Octave command on Linux:

javaaddpath("/Absolute/path/to/Octave/Tinkerforge.jar");


To make this change persistent you can add the command to the following file on Linux:

~/.octaverc


If this file didn't exist yet you can just create it. Octave has to be restarted after changing this file.

## Testing an Example¶

To test a MATLAB/Octave example Brick Daemon and Brick Viewer have to be installed first. Brick Daemon acts as a proxy between the USB interface of the Bricks and the API bindings. Brick Viewer connects to Brick Daemon and helps to figure out basic information about the connected Bricks and Bricklets.

### MATLAB¶

As an example we will run the Stepper Brick configuration example. To do this open the matlab_example_configuration.m file from the matlab/examples/brick/stepper/ folder in MATLAB.

In the example HOST and PORT specify at which network address the Stepper Brick can be found. If it is connected locally to USB then localhost and 4223 is correct. The UID value has to be changed to the UID of the connected Stepper Brick, which you can figure out using Brick Viewer:

HOST = 'localhost';
PORT = 4223;
UID = 'XYZ'; % Change to your UID


Now you're ready to test the examples.

### Octave¶

As an example we will run the Stepper Brick configuration example. To do this open the octave_example_configuration.m file from the octave/examples/brick/stepper/ folder in Octave.

In the example HOST and PORT specify at which network address the Stepper Brick can be found. If it is connected locally to USB then localhost and 4223 is correct. The UID value has to be changed to the UID of the connected Stepper Brick, which you can figure out using Brick Viewer:

HOST = "localhost";
PORT = 4223;
UID = "XYZ"; % Change to your UID


Now you're ready to test the examples.

#### Function vs Script Files¶

The Octave examples are function files. To execute them directly from a terminal, they have to be extended to script files. Just add a call to the example function at the end of the example:

function octave_example_configuration()
% ...
end