Control Surface master
MIDI Control Surface library for Arduino
Custom-Note-LED-Input-Element-Callback.ino

Custom-Note-LED-Input-Element-Callback

This example demonstrates how to attach custom actions to incoming Note or Control Change MIDI events.

Boards:
AVR, AVR USB, Due, Nano 33 IoT, Nano 33 BLE, Teensy 3.x

Connections

Behavior

If a MIDI Note On event for note 0x3C (C4 or middle C) is sent, the built-in LED will light up at full brightness, if a Note Off event for that note is sent, the LED will light dimly.
(A Note On event with a velocity of zero also counts as a Note Off event.)

Mapping

Route the MIDI output of a MIDI keyboard to the Arduino's MIDI input. Then play a middle C on the keyboard.

Written by PieterP, 2020-03-10
https://github.com/tttapa/Control-Surface

#include <Control_Surface.h> // Include the Control Surface library
// Instantiate a MIDI over USB interface.
// MIDI Input Element that listens for MIDI Note events that turns on the LED at
// full brightness if the note value (velocity) is above the threshold,
// and turns on the LED at a lower brightness if the value is below the
// threshold.
class CustomNoteLED
// First, inherit from the MatchingMIDIInputElement base class. Indicate that
// you want to listen to MIDI Note events by specifying the MIDI message type,
// and use a simple 2-byte message matcher, since MIDI Note events have two
// data bytes.
: public MatchingMIDIInputElement<MIDIMessageType::NOTE_ON,
TwoByteMIDIMatcher> {
public:
// Constructor
CustomNoteLED(pin_t ledPin, MIDIAddress address, uint8_t lowBrightness)
: MatchingMIDIInputElement(address), ledPin(ledPin),
lowBrightness(lowBrightness) {}
// Called once upon initialization, set up the pin mode for the LED,
// and output the initial value.
void begin() override {
ExtIO::analogWrite(ledPin, lowBrightness);
}
// Called when an incoming MIDI Note message matches this element's matcher
// (i.e. it has the right MIDI address, channel and cable).
// The match object that's passed as a parameter contains the velocity value
// of the Note message that matched.
if (match.value >= threshold)
else
ExtIO::analogWrite(ledPin, lowBrightness);
}
// Called when the input element is reset (e.g. by an "All notes off" MIDI
// event).
void reset() override { ExtIO::analogWrite(ledPin, lowBrightness); }
private:
pin_t ledPin;
uint8_t lowBrightness;
const static uint8_t threshold = 0x01;
};
// Instantiate the LED that will light up when middle C is playing.
CustomNoteLED led {
3, // Pin with the LED connected (PWM capable)
{MIDI_Notes::C(4), CHANNEL_1}, // Note C4 on MIDI channel 1
10, // Intensity when off
};
void setup() {
Control_Surface.begin(); // Initialize Control Surface
}
void loop() {
Control_Surface.loop(); // Update the Control Surface
}
constexpr PinStatus_t HIGH
constexpr PinMode_t OUTPUT
constexpr Channel CHANNEL_1
Definition: Channel.hpp:118
The main header file that includes all Control-Surface header files.
Control_Surface_ & Control_Surface
A predefined instance of the Control Surface to use in the Arduino sketches.
void begin()
Initialize the Control_Surface.
void loop()
Update all MIDI elements, send MIDI events and read MIDI input.
A type-safe utility class for saving a MIDI address consisting of a 7-bit address,...
virtual void begin()
Initialize the input element.
virtual void reset()
Reset the input element to its initial state.
The MIDIInputElement base class is very general: you give it a MIDI message, and it calls the updateW...
MatchingMIDIInputElement(const Matcher &matcher)
virtual void handleUpdate(typename Matcher::Result match)=0
A class for MIDI interfaces sending MIDI messages over a USB MIDI connection.
void analogWrite(pin_t pin, analog_t val)
An ExtIO version of the Arduino function.
void pinMode(pin_t pin, PinMode_t mode)
An ExtIO version of the Arduino function.
void digitalWrite(pin_t pin, PinStatus_t val)
An ExtIO version of the Arduino function.
uint16_t pin_t
The type for Arduino pins (and ExtendedIOElement pins).
constexpr Note C
C (Do)
Definition: Notes.hpp:40