Arduino library for creating MIDI controllers and other MIDI devices.
GPL-3.0 License
Control Surface is an Arduino library for building MIDI controllers and control surfaces.
At its core, the library features a flexible MIDI abstraction layer with support for serial 5-pin DIN MIDI, MIDI over USB, MIDI over BLE, etc. These MIDI interfaces are compatible with a wide range of Arduino boards (a full table can be found here) and are useful in any Arduino MIDI project.
In addition to MIDI input/output, Control Surface also provides easy-to-use utilities intended for building MIDI controllers, supporting controls that send MIDI messages ─ like potentiometers, push buttons, rotary encoders, etc. ─ and controls that react to incoming MIDI messages ─ LEDs, displays, and so on. More advanced controls that combine MIDI input and output ─ such as motorized faders ─ are supported as well.
In projects with large numbers of inputs and outputs, Control Surface allows you to seamlessly add multiplexers, shift registers and other port expanders, and treat them as if they were ordinary GPIO pins.
Table of contents ¶ Example usage ¶ Getting started ¶ Documentation ¶ Feature overview ¶ Supported boards ¶ Change log and updating
An extensive list of examples can be found in the documentation. Below are a handful of simple examples that give an idea of how the Control Surface library can be used.
Example 1: A complete sketch for a MIDI controller with a potentiometer that sends out MIDI Control Change message can be written in just five lines of code:
#include <Control_Surface.h>
USBMIDI_Interface midi;
CCPotentiometer pot { A0, MIDI_CC::General_Purpose_Controller_1 };
void setup() { Control_Surface.begin(); }
void loop() { Control_Surface.loop(); }
Example 2: Larger MIDI controllers can be implemented very easily as well, with clean and easy to modify code. The following sketch is for 8 potentiometers (connected using an analog multiplexer) that send out MIDI Control Change messages over USB. A detailed walkthrough of this example can be found on the Getting Started page.
#include <Control_Surface.h> // Include the library
USBMIDI_Interface midi; // Instantiate a MIDI Interface to use
// Instantiate an analog multiplexer
CD74HC4051 mux {
A0, // Analog input pin
{3, 4, 5} // Address pins S0, S1, S2
};
// Create an array of CCPotentiometer objects that send out MIDI Control Change
// messages when you turn the potentiometers connected to the 8 inputs of the mux.
CCPotentiometer volumePotentiometers[] {
{ mux.pin(0), { MIDI_CC::Channel_Volume, Channel_1 } },
{ mux.pin(1), { MIDI_CC::Channel_Volume, Channel_2 } },
{ mux.pin(2), { MIDI_CC::Channel_Volume, Channel_3 } },
{ mux.pin(3), { MIDI_CC::Channel_Volume, Channel_4 } },
{ mux.pin(4), { MIDI_CC::Channel_Volume, Channel_5 } },
{ mux.pin(5), { MIDI_CC::Channel_Volume, Channel_6 } },
{ mux.pin(6), { MIDI_CC::Channel_Volume, Channel_7 } },
{ mux.pin(7), { MIDI_CC::Channel_Volume, Channel_8 } },
};
void setup() {
Control_Surface.begin(); // Initialize the Control Surface
}
void loop() {
Control_Surface.loop(); // Update the Control Surface
}
Example 3: Control Surface also supports many types of MIDI inputs. For example, an LED that turns on when a MIDI Note On message for middle C is received:
#include <Control_Surface.h>
USBMIDI_Interface midi;
NoteLED led { LED_BUILTIN, MIDI_Notes::C[4] };
void setup() { Control_Surface.begin(); }
void loop() { Control_Surface.loop(); }
Example 4: Control Surface's MIDI interfaces can also be used directly, for example, to implement a MIDI-over-USB to MIDI-over-BLE adapter:
#include <Control_Surface.h>
// Instantiate MIDI over BLE and MIDI over USB interfaces
BluetoothMIDI_Interface midi_ble;
USBMIDI_Interface midi_usb;
// Pipes allow routing between MIDI interfaces
BidirectionalMIDI_Pipe pipes;
void setup() {
// Route the MIDI input from the USB interface to the BLE interface,
// and the MIDI input from the BLE interface to the USB interface
midi_usb | pipes | midi_ble;
// Initialize the MIDI interfaces
MIDI_Interface::beginAll();
}
void loop() {
// Continuously poll all interfaces and route the traffic between them
MIDI_Interface::updateAll();
}
See the Getting Started page to get started using the library. It'll also point you to the Installation Instructions.
The MIDI tutorial might be useful if you want to use Control Surface as a regular MIDI library, for sending and receiving MIDI messages.
Detailed documentation for this library can be found here: Documentation Arduino examples can be found here: Examples
The User Manual is the best entry point to the documentation. To get a complete overview of all features of the Control Surface library, have a look at the following section and at the Topics page.
You can find an answer to some frequently asked questions on the FAQ page.
This library turns your Arduino-compatible board into a MIDI control surface. Just connect some push buttons, potentiometers, LEDs ... and declare them in your code.
The following sections give a brief overview of the features of the library.
→ MIDI Interfaces documentation
Digital inputs are debounced, and analog inputs are filtered using digital filters and hysteresis. This results in high accuracy without noise, without introducing latency.
These MIDI control outputs can be used to send MIDI notes, Control Change, Pitch Bend, Program/Patch change, etc.
→ MIDI Output Elements documentation
A large portion of the Mackie Control Universal (MCU) protocol is implemented.
→ MIDI Input Elements documentation
→ Control Surface Motor Fader documentation
All controls can be arranged in banks: for example, if you have only 4 physical faders, you can make them bankable, so they can be used to control the volume of many more different tracks. Changing banks can be done using push buttons, rotary encoders, etc. Apart from banks and bank selectors, you can also add transposers to change the key of your notes, for example.
In order to save some IO pins, the library natively supports multiplexers (e.g. 74HC4051 or 74HC4067) to read many switches or potentiometers, Shift Registers (e.g. 74HC595) to drive many LEDs, MAX7219 LED drivers, etc.
If you are using a Teensy 3.x or 4.x, you can use it as a USB audio interface. Just add an I²S DAC (e.g. PCM5102) and 5 lines of code, and you can start playing audio through your Teensy, by combining Control Surface with the Teensy Audio library. You can also add volume controls and VU meters for these audio connections.
Thanks to the structure of the library, you can easily add your own MIDI or display elements, using some minimal, high level code. All low level stuff is completely reusable (e.g. all MIDI operations, debouncing switches, filtering analog inputs, and so on).
Download the repository as a ZIP archive by going to the home page of the repository and clicking the green Code button in the top right, then choosing “Download ZIP”. Alternatively, click the following direct download link: https://github.com/tttapa/Control-Surface/archive/refs/heads/main.zip
Open the Arduino IDE, and go to the Sketch > Include Library > Add .ZIP Library menu. Then navigate to your downloads directory where you just downloaded the library. Select it, and click Ok.
For each commit, the continuous integration tests compile the examples for the following boards:
This covers a very large part of the Arduino platform, and similar boards will also work. For example, the Arduino Nano, Mega, Micro, Pro Micro, Teensy 2.0, Teensy LC, Teensy 3.x, Teensy 4.x are all known to work.
If you have a board that's not supported, please open an issue and let me know!
Note that MIDI over USB and MIDI over Bluetooth are not supported on all boards. See the MIDI over USB documentation page for a table with supported features per board.
MIDI_Notes::X(n)
by MIDI_Notes::X[n]
to avoid issues with the Arduino F(...)
macro.BluetoothMIDI_Interface
on the Raspberry Pi Pico W.ArduinoBLE
backend for BluetoothMIDI_Interface
.BluetoothMIDI_Interface
, with support for the NimBLE and ArduinoBLE backends.ControlChange
should be used instead of CONTROL_CHANGE
. If you continueCHANNEL_x
and CABLE_x
constants have been deprecated inChannel_x
and Cable_x
. This was done toCS
namespace has been renamed to cs
.Encoder
class has been replaced by AHEncoder
.SoftwareSerialMIDI_Interface.hpp
SoftwareSerialDebugMIDI_Interface.hpp
.sendCC()
) have been deprecatedsendControlChange()
). See theControl_Surface.setMIDIInputCallbacks()
now takes four arguments instead ofF
to F_
in orderF()
macro and its functional equivalentMIDI_Notes::C(4)
instead of note(C, 4)
.SPI
SPI1
or SPI2
NoteBitmapDisplay
class has been renamed to BitmapDisplay
.NoteValueLED
and CCValueLED
classes (and similar) have been replacedNoteLED
and CCLED
respectively.BitmapDisplay
, VPotDisplay
, VUDisplay
etc. are<>
after the type names, e.g.BitmapDisplay<>
, VPotDisplay<>
, etc.LCDDisplay
are now one-based: 1
is the first line and2
is the second line. This is more consistent with the track parameter and0
and the1
.)Encoder.h
in your sketches.Control_Surface.MIDI()
was used to get the MIDI interface used byControl_Surface.sendCC(...)
and the other similar methods directly.MultiMIDI_Interface
wasNoteRangeFastLED
and the like now takes a secondsrc/AH/Settings/Settings.hpp
ANALOG_FILTER_SHIFT_FACTOR
bits wide instead of 7. By default this isFilteredAnalog<>::getMaxRawValue()
function.analog_t f(analog_t raw)
,