MIDIUSB example

midi.h

#include <MIDIUSB.h>

int note;
int previous_note = 0;
int current_note = 0;

void noteOn(byte channel, byte pitch, byte velocity) {
  midiEventPacket_t noteOn = {0x09, 0x90 | channel, pitch, velocity};
  MidiUSB.sendMIDI(noteOn);
}

void noteOff(byte channel, byte pitch, byte velocity) {
  midiEventPacket_t noteOff = {0x08, 0x80 | channel, pitch, velocity};
  MidiUSB.sendMIDI(noteOff);
}

void setup() {}

void loop() {
  // read finger position and map to a note
  readFingerPositionAndTranslateToNote(); // <- you should use your function here
  
  if (current_note != previous_note) {
    // stop playing previous note
    noteOff(0, previous_note, 127);
    MidiUSB.flush();
    
    // where "note" is a MIDI note number in this table https://computermusicresource.com/midikeys.html
    noteOn(0, note, 127);
    MidiUSB.flush();
  }
}