Schoo Project-Arduino Midi Drumpads

Using Arduino Audio
13

MIDI is send over 16 channels. Channel 10 is normally reserved for percussion. See:-

You are sending stuff on channel 0, so you can never get the percussion set with that.

You need to send stuff on channel 10, to do this change your code to:-

void midiNoteOn(byte note, byte midiVelocity)
{
Serial.write(NOTE_ON_CMD + 9);
Serial.write(note);
Serial.write(midiVelocity);
}

void midiNoteOff(byte note, byte midiVelocity)
{
Serial.write(NOTE_OFF_CMD + 9);
Serial.write(note);
Serial.write(midiVelocity);
}

I would also skip sending the note off as the percussion drum set does not need it and it will only cut notes short because you have no delay between on and off.
Percussion notes are from note 35 to note 81 although some sound generators might have things for other notes as well.