MIDI Omni Mode

[nativeVS]

En lieu of me missing the obvious, is there an easy way to transmit on all MIDI channels ?
Looking at Channel.hpp (superficially) would suggest there isn't, but maybe I'm just missing something.

[tttapa]

No, this is not supported using the Channel class.

You would have to send the messages yourself, for example:

#include <Control_Surface.h>

USBMIDI_Interface midi;
MIDIAddress addr{0x3C};
Button btn{2};

void setup() {
  Control_Surface.begin();
  btn.begin();
}

void loop() {
  Control_Surface.loop();
  if (btn.update() == Button::Falling) {
    for (uint8_t delta = 0; delta < 16; ++delta) { // Loop over all 16 channels
      RelativeMIDIAddress offset{0, delta}; // {address, channel}
      Control_Surface.sendNoteOn(addr + offset, 127);
    }
  }
}

To make the existing MIDI elements “omni”, have a look at the Custom-MIDI-Sender.ino example.
You could use something like this:

#include <Control_Surface.h>

USBMIDI_Interface midi;

class OmniNoteSender {
  public:
    OmniNoteSender(uint8_t onVelocity, uint8_t offVelocity)
      : onVelocity(onVelocity), offVelocity(offVelocity) {}

    void sendOn(MIDIAddress address) {
      for (uint8_t i = 0; i < 16; ++i)
        Control_Surface.sendNoteOn(address + RelativeMIDIAddress{0, i}, onVelocity);
    }

    void sendOff(MIDIAddress address) {
      for (uint8_t i = 16; i--> 0;)
        Control_Surface.sendNoteOff(address + RelativeMIDIAddress{0, i}, offVelocity);
    }

  private:
    uint8_t onVelocity, offVelocity;
};

struct OmniNoteButton : MIDIButton<OmniNoteSender> {
  OmniNoteButton(pin_t pin, MIDIAddress address, 
                 uint8_t onVelocity = 127, uint8_t offVelocity = 127)
    : MIDIButton(pin, address, {onVelocity, offVelocity}) {}
};

using namespace MIDI_Notes;

OmniNoteButton button = {
  2,            // button pin
  note(C, 4),   // MIDI address
  127,          // On velocity
  127,          // Off velocity
};

void setup() {
  Control_Surface.begin();
}

void loop() {
  Control_Surface.loop();
}