MIDI Controls

Output values from controls on MIDI control surface

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Libraries:
Audio Toolbox / Sources
DSP System Toolbox / Sources

Description

The MIDI Controls block outputs values from controls on a MIDI control surface in real time. Use the MIDI Controls block to interact with your audio processing model.

The MIDI Controls block combines the functionality of the general MIDI functions in MATLAB^®: midicontrols, midiread, midisync. Use the MATLAB midiid command to discover MIDI device names or MIDI device control numbers.

Examples

Output Values from MIDI Control Surface

The example shows how to set the MIDI Controls block parameters to output control values from your MIDI device.

• Open Model

Using a MIDI Control Surface to Interact with a Simulink Model

Use a MIDI control surface as a physical user interface to a Simulink® model, allowing you to use knobs, sliders and buttons to interact with that model. It can be used in Simulink as well as with generated code running on a workstation.

• Open Model

Ports

Output

Port_1 — Output signal

matrix

The output size of the MIDI Controls block is determined by the MIDI controls and MIDI control numbers parameters.

The output data type is determined by the Output mode parameter.

Data Type	Output Mode
double	Normalized (0-1)
uint8	RAW MIDI (0-127)

Data Types: double | uint8

Parameters

MIDI device — MIDI control surface your block listens to

Default (default) | Specify other

To set the default MIDI device, use the setpref function. For example, if the device is named BCF2000, at the MATLAB command line, enter:

setpref('midi','DefaultDevice','BCF2000');

MIDI device name — Device name of MIDI control surface your block listens to

character vector

The MIDI device name is assigned by the device manufacturer or host operating system, and specified as a character vector. Use midiid to interactively identify your MIDI device.

To enable this parameter, set MIDI device to Specify other.

MIDI controls — Specify if block responds to all controllers or specific controllers on MIDI surface

Respond to any control (default) | Respond to specified controls

This parameter also determines the size of the block output port. If you choose Respond to any control, then the block output is a scalar corresponding to the value of the most recently manipulated control.

MIDI control numbers — Control numbers associated with MIDI surface controllers that your block responds to

0 (default) | integer | array of integers

Use midiid to interactively identify the control numbers of your MIDI device. This parameter is available when you set MIDI controls to Respond to specified controls.

Initial values — Control numbers associated with MIDI surface controllers that your block responds to

0 (default) | scalar | array

If you specify Initial values as a scalar, all controls specified by MIDI control numbers are assigned that value.

If you specify Initial values as an array, the array must be the same size as MIDI control numbers.

Send initial values to device at start — Synchronize MIDI surface with values specified initial values

off (default) | on

Select this parameter to synchronize a MIDI device with values specified by the Initial values when simulation starts. If your MIDI device can receive and respond to messages, it adjusts its controls as specified. This parameter is valid only when MIDI controls is set to Respond to specified controls.

Many MIDI devices are not bidirectional. Selecting this parameter with a unidirectional device has no effect. The MIDI Controls block cannot tell whether a value is successfully sent to a device or even whether the device is bidirectional. If sending a value fails, no errors or warnings are generated.

Output Mode — Output mode for MIDI control value

Normalized (0-1) (default) | RAW MIDI (0-127)

Output mode for MIDI control value, specified as Normalized (0-1) or RAW MIDI (0-127).

Block Characteristics

Data Types	double | integer
Direct Feedthrough	no
Multidimensional Signals	no
Variable-Size Signals	no
Zero-Crossing Detection	no

Tips

• The MIDI Controls block is not supported for rapid accelerator mode.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

The executable generated from this block relies on prebuilt dynamic library files (.dll files) included with MATLAB. Use the packNGo function to package the code generated from this object and all the relevant files in a compressed zip file. Using this zip file, you can relocate, unpack, and rebuild your project in another development environment where MATLAB is not installed. For more details, see Run Audio I/O Features Outside MATLAB and Simulink.