Midi controller

#include <Adafruit_MCP23017.h>
#include <Adafruit_MCP3008.h>
#include "MIDIUSB.h"

Adafruit_MCP3008 adc1;
Adafruit_MCP3008 adc2;

Adafruit_MCP23017 mcp1;
Adafruit_MCP23017 mcp2;
Adafruit_MCP23017 mcp3;
Adafruit_MCP23017 mcp4;

void setup(){
  mcp1.begin(0);
  for(int i = 0;i<=16;i++){
    mcp1.pinMode(i, INPUT);
    mcp1.pullUp(i, HIGH);


  mcp2.begin(1);
  for(int i = 0;i<=16;i++){
    mcp2.pinMode(i, INPUT);
    mcp2.pullUp(i, HIGH);


  mcp3.begin(2);
  for(int i = 0;i<=16;i++){
    mcp3.pinMode(i, INPUT);
    mcp3.pullUp(i, HIGH);


  mcp4.begin(3);
  for(int i = 0;i<=16;i++){
    mcp4.pinMode(i, INPUT);
    mcp4.pullUp(i, HIGH);


  adc1.begin(9);
  adc2.begin(8);

}

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 taster(int mcpNR, int tasterNR, int midinote){
  switch (mcpNR) {
    case 1:
      if (mcp1.digitalRead(tasterNR) == LOW) {
        noteOn(0,midinote,127);
        MidiUSB.flush();
      }
      else {
        noteOff(0,midinote,127);
        MidiUSB.flush();

      break;

    case 2:
      if (mcp2.digitalRead(tasterNR) == LOW) {
        noteOn(0,midinote,127);
        MidiUSB.flush();
      }
      else {
        noteOff(0,midinote,127);
        MidiUSB.flush();

      break;

    case 3:
      if (mcp3.digitalRead(tasterNR) == LOW) {
        noteOn(0,midinote,127);
        MidiUSB.flush();
      }
      else {
        noteOff(0,midinote,127);
        MidiUSB.flush();

      break;

    case 4:
      if (mcp4.digitalRead(tasterNR) == LOW) {
        noteOn(0,midinote,127);
        MidiUSB.flush();
      }
      else {
        noteOff(0,midinote,127);
        MidiUSB.flush();

      break;
    default:
      break;

}

void fader(int adcNR, char faderNR, int midinote){
  switch (adcNR){
    case 1:
      noteOn(0,midinote,map(adc1.readADC(faderNR),0,1023,0,127));
      MidiUSB.flush();
      break;

    case 2:
      noteOn(0,midinote,map(adc2.readADC(faderNR),0,1023,0,127));
      MidiUSB.flush();
      break;

}


void loop() {
  delay(10);
  fader(1,0,1); //Fader links
  fader(1,1,2);
  fader(1,2,3);
  fader(1,3,4);
  fader(1,4,5);
  fader(1,5,6);
  fader(1,6,7);
  fader(1,7,8);

  fader(2,2,9); //Fader rechts
  fader(2,3,10);
  fader(2,4,11);
  fader(2,5,12);
  fader(2,6,13);
  fader(2,7,14);

  taster(2,0,15); //Buttons links unten
  taster(2,1,16);
  taster(2,2,17);
  taster(2,3,18);
  taster(2,4,19);
  taster(2,5,20);
  taster(2,6,15);
  taster(2,7,22);
  taster(2,8,23);
  taster(2,9,24);
  taster(2,10,25);
  taster(2,11,26);
  taster(2,12,27);
  taster(2,13,28);
  taster(2,14,29);
  taster(2,15,30);

  taster(4,7,31); //Buttons rechts unten
  taster(4,9,32);
  taster(4,8,33);
  taster(4,7,34);
  taster(4,8,35);
  taster(4,7,36);
  taster(4,9,37);
  taster(4,8,38);
  taster(4,7,39);
  taster(4,9,40);
  taster(4,8,41);
  taster(4,7,42);

  taster(1,0,57); //Buttons links oben
  taster(1,1,53);
  taster(1,2,51);
  taster(1,3,55);
  taster(1,4,47);
  taster(1,5,49);
  taster(1,6,43);
  taster(1,7,45);
  taster(1,8,46);
  taster(1,9,44);
  taster(1,10,50);
  taster(1,11,48);
  taster(1,12,56);
  taster(1,13,52);
  taster(1,14,54);
  taster(1,15,58);

  taster(3,7,59); //Buttons rechts oben
  taster(3,9,60);
  taster(3,8,61);
  taster(3,7,62);
  taster(3,8,63);
  taster(3,7,64);
  taster(3,9,65);
  taster(3,8,66);
  taster(3,7,67);
  taster(3,9,68);
  taster(3,8,69);
  taster(3,7,70);
}