#include <Bounce.h>
 
#include <Wire.h>
#include "Adafruit_MPR121.h"
// Connection Teensy2 SCL = DO, SDA = D1
 
// Touch
Adafruit_MPR121 cap = Adafruit_MPR121();
int currentTouchValues[4]; 
int lastTouchValues[4]; 
const int touchThreshold = 60;
 
// the MIDI channel number to send messages
const int channel = 1;
 
// the MIDI continuous controller for each analog input
const int controllerA0 = 10; // 10 = pan position
const int controllerA1 = 11; // 11 = volume/expression
const int controllerA2 = 12; // 91 = reverb level
const int controllerA3 = 13; // 93 = chorus level
const int controllerA4 = 14; // 93 = chorus level
const int controllerA5 = 15; // 93 = chorus level
 
void setup() {
  delay(1000);
  cap.begin(0x5A);
   for (uint8_t i=0; i<4; i++) {
    lastTouchValues[i] = cap.filteredData(i);
    //Serial.println(cap.filteredData(i));
  }
}
 
// store previously sent values, to detect changes
int previousA0 = -1;
int previousA1 = -1;
int previousA2 = -1;
int previousA3 = -1;
int previousA4 = -1;
int previousA5 = -1;
elapsedMillis msec = 0;
 
// delay 
long previousMillis = 0;
long intervalle = 50;   
 
void loop() {
  // only check the analog inputs 50 times per second,
  // to prevent a flood of MIDI messages
unsigned long currentMillis = millis();
 
  if(currentMillis - previousMillis > intervalle) {
    previousMillis = currentMillis;
 
    int n0 = analogRead(A0) / 8;
    int n1 = analogRead(A1) / 8;
    int n2 = analogRead(A2) / 8;
    int n3 = analogRead(A3) / 8;
    int n4 = analogRead(A4) / 8;
    int n5 = analogRead(A5) / 8;    
    // only transmit MIDI messages if analog input changed
    if (n0 != previousA0) {
      usbMIDI.sendControlChange(controllerA0, n0, channel);
      previousA0 = n0;
    }
    if (n1 != previousA1) {
      usbMIDI.sendControlChange(controllerA1, n1, channel);
      previousA1 = n1;
    }
    if (n2 != previousA2) {
      usbMIDI.sendControlChange(controllerA2, n2, channel);
      previousA2 = n2;
    }
    if (n3 != previousA3) {
      usbMIDI.sendControlChange(controllerA3, n3, channel);
      previousA3 = n3;
    }
    if (n4 != previousA4) {
      usbMIDI.sendControlChange(controllerA4, n4, channel);
      previousA4 = n4;
    }
    if (n5 != previousA5) {
      usbMIDI.sendControlChange(controllerA5, n5, channel);
      previousA5 = n5;
    }
 
    for (uint8_t i=0; i<4; i++) {
      currentTouchValues[i] = cap.filteredData(i);
      if ((currentTouchValues[i] - lastTouchValues[i]) < -touchThreshold) usbMIDI.sendControlChange(i, 127, channel);
      if ((currentTouchValues[i] - lastTouchValues[i]) > touchThreshold) usbMIDI.sendControlChange(i, 0, channel);
      lastTouchValues[i] = currentTouchValues[i];
    }
  }
 
  // MIDI Controllers should discard incoming MIDI messages.
  // http://forum.pjrc.com/threads/24179-Teensy-3-Ableton-Analog-CC-causes-midi-crash
  while (usbMIDI.read()) {
    // ignore incoming messages
  }
}