Self build Midi Controller

byte read_two_encoders() {
  int8_t enc_states[] = {0,-1,1,0,1,0,0,-1,-1,0,0,1,0,1,-1,0};
  static uint8_t old_AB1, old_AB2 = 0;
  byte rtn = 0;

  old_AB1 <<= 2; //remember previous state
  old_AB1 |= (ENC_PORT & 0b11); //add current state
  old_AB2 <<= 2; //remember previous state
  old_AB2 |= (ENC_PORT & 0b1100) >> 2; //add current state
  rtn |= (enc_states[(old_AB1 & 0b1111)]) & 0b11;
  return rtn | ((enc_states[(old_AB2 & 0b1111)]) & 0b11) << 2;
}

 for(int i = 0; i < NUM_POTS; i++) {
    PORTD = (NUM_POTS > 8 && i >= 8) ? (i % 8) << 2 : i << 2; // set pins 2, 3 and 4 to value between 0 (00000) and 7 (11100) to select the pot
    if (i > 0 && (i % 8 == 0)) chipSelect++; // increase chip select index every 8 pots
    potValues[i] = analogRead(potReadPins[chipSelect]);
    if (abs(potValues[i] - prevPotValues[i]) > SMOOTHING) {
      prevPotValues[i] = potValues[i];
      midiStreamCC(i, map(potValues[i],5,1020,0,127));
    }
  }

void midiStreamNote(const uint8_t pitch, const bool onoff) {
#ifdef DEBUG
  uint8_t command = ((onoff)? 0x90 : 0x80);
  Serial.print("cmd:");Serial.print(command >> 4,HEX);   // command type 0..15
  Serial.print(" ch:");Serial.print((MIDI_CHANNEL & 0x0f),DEC);  // channel 0..15
  Serial.print(" note:");Serial.print(pitch & 0x7f,DEC);   // note 0..127
  Serial.print(" vel:");Serial.println(MIDI_VELOCITY,HEX); // velocity 0..127
#else
  if (onoff) {
    midi.sendNoteOn(MIDI_CHANNEL, pitch & 0x7f, 0x7f);
  } else {
    midi.sendNoteOff(MIDI_CHANNEL, pitch & 0x7f, 0x7f);
  }
#endif
}

void midiStreamCC(const uint8_t cc, const uint8_t val) {
#ifdef DEBUG
  Serial.print("cmd:");Serial.print(cc,DEC);   // command type 0..15
  Serial.print(" ch:");Serial.print(MIDI_CHANNEL,DEC);  // channel 0..15
  Serial.print(" val:");Serial.print(val & 0x7f,DEC);   // note 0..127
  Serial.print(" vel:");Serial.println(MIDI_VELOCITY,DEC); // velocity 0..127
#else
  midi.sendControlChange(MIDI_CHANNEL, cc, val);
#endif
}