#include<MIDI.h>
MIDI_CREATE_DEFAULT_INSTANCE();
#include<CapacitiveSensor.h>
#include <LiquidCrystal.h>

#define ControlChange 0xB0
#define NoteOn 0x90

//Arduino Pin Assignments
const int motorDown    = 5;   //H-Bridge control to make the motor go down
const int motorUp      = 6;   //H-Bridge control to make the motor go up
const int wiper        = A0;   //Position of fader relative to GND (Analog 0)
const int touchSend    = 4;   //Send pin for Capacitance Sensing Circuit (Digital 7)
const int touchReceive = 2;   //Receive pin for Capacitance Sensing Circuit (Digital 8)
const int channelLeft = 12;     // the number of the channelLeft (Digital 12) pin
const int channelRight = 13;     // the number of the channelRight (Digital 13) pin

//Variables
double   faderMax        = 0;     //Value read by fader's maximum position (0-1023)
double   faderMin        = 0;     //Value read by fader's minimum position (0-1023)
int      faderChannel    = 0;     //Value from 1-8
int      chLeftBtn       = 0;
int      chRightBtn      = 0;
int      faderPositionLoop;
bool     touched         = false; //Is the fader currently being touched?
bool     positionUpdated = false; //Since touching, has the MIDI position been updated?
String ascii = "";
String oldAscii = "";
bool compare = true;
//LCD pins
LiquidCrystal lcd(52, 50, 46, 44, 42, 40);

byte channel1LCD[]  {0xf0, 0x00, 0x00, 0x66, 0x05, 0x00, 0x10};
CapacitiveSensor touchLine = CapacitiveSensor(touchSend, touchReceive);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(31250);

  MIDI.begin(MIDI_CHANNEL_OMNI);  //Receive messages on all MIDI channels
  MIDI.turnThruOff();             //We don't need MIDI through for this
  MIDI.setHandleSystemExclusive(handle_sysex);
  pinMode (motorUp, OUTPUT);
  pinMode (motorDown, OUTPUT);

  calibrateFader();

}

void loop() {

int newPosition;
  // update physical fader position
  checkTouch();                    // check if phyisical fader has been touched
  if (!positionUpdated) {           // if it has update midi to protools
    updateFaderMidi();
    newPosition = (((float)(analogRead(wiper) - faderMin) / (faderMax - faderMin)) * 16383);
    updateFader(faderPositionLoop);
    positionUpdated = true;
  }
  else {
    faderPositionLoop = checkMIDI(); // run midi check and return fader position from protools
    updateFader(faderPositionLoop);      // update physical fader with midi info

  }

}


void calibrateFader() {
  //Send fader to the top and read max position
  digitalWrite(motorUp, HIGH);
  delay(1000);
  digitalWrite(motorUp, LOW);
  faderMax = analogRead(wiper) - 5;


  //Send fader to the bottom and read min position
  digitalWrite(motorDown, HIGH);
  delay(1000);
  digitalWrite(motorDown, LOW);
  faderMin = analogRead(wiper) + 5;

}


// check for incoming midi signals
int checkMIDI() {
  static byte velocity1 = 0;
  static byte velocity2 = 0;
  static int faderPosition = 0;
  static int oldMidi = 0;
  if (MIDI.read()  && MIDI.getChannel() == 1 && MIDI.getType() == ControlChange && MIDI.getData1() == 0x00) // check for MSB
  {
    velocity1 = MIDI.getData2();
  }
  if (MIDI.read()  && MIDI.getChannel() == 1 && MIDI.getType() == ControlChange && MIDI.getData1() == 0x20)  // Check for LSB
  {
    velocity2 = MIDI.getData2();
  }
  faderPosition = (((velocity1 << 7) + velocity2) >> 4); //bitwise math to combine MSB and LSB

  return faderPosition ;   // remember to initialize using variable assignment with function call
}



void updateFader(int fposition) {
  if (fposition < analogRead(wiper) - 10 && fposition > faderMin && !touched) {
    digitalWrite(motorDown, HIGH);
    while (fposition < analogRead(wiper) - 10 && !touched) {};  //Loops until motor is done moving
    digitalWrite(motorDown, LOW);
  }
  else if (fposition > analogRead(wiper) + 10 && fposition < faderMax && !touched) {
    digitalWrite(motorUp, HIGH);
    while (fposition > analogRead(wiper) + 10 && !touched) {}; //Loops until motor is done moving
    digitalWrite(motorUp, LOW);
  }
}

void checkTouch() {
  int movedFader;
  //For the CapacitiveSensor comparison below,
  //700 is arbitrary and may need to be changed
  //depending on the fader cap used (if any).

  if (!touched && touchLine.capacitiveSensor(30) >= 3000) {
    touched = true;

    //Send MIDI Touch On Message
    MIDI.send(ControlChange, 0x0f, 0x00, 0x01);
    MIDI.send(ControlChange, 0x2f, 0x40, 0x01);
    digitalWrite(motorUp, LOW);
    digitalWrite(motorDown, LOW);
  }
  else if (touched && touchLine.capacitiveSensor(30) < 3000) {
    touched = false;

    MIDI.send(ControlChange, 0x0f, 0x00, 0x01);
    MIDI.send(ControlChange, 0x2f, 0x00, 0x01);
  }

  if (touched) {
    positionUpdated = false;
  }
}

void updateFaderMidi() {
  static int oldValue = 0;                        // set old value to 0 only for first time
  int velocity = faderPosition();

  if (oldValue != velocity) {
    byte faderMSB = (velocity >> 7) ;               // get MSB value in 7 bit
    MIDI.send(ControlChange, 0x00, faderMSB, 0x01); // send MSB value

    byte faderLSB = (velocity & 0x7f);               // get LSB value
    MIDI.send(ControlChange, 0x20, faderLSB, 0x01); // send new value
    oldValue = velocity;

  }
}

//Returns a MIDI pitch bend value for the fader's current position
//Cases ensure that there is a -infinity (min) and max value despite possible math error
int faderPosition() {
  int fposition = analogRead(wiper);

  int returnValue = 0;

  if (fposition <= faderMin) {
    returnValue = 0;
  }
  else if (fposition >= faderMax) {
    returnValue = 16383;
  }
  else {
    returnValue = ((float)(fposition - faderMin) / (faderMax - faderMin)) * 16383;
  }

  return returnValue;

}