#define w1 1
#define w2 1
#define w3 1
#define w4 1

void noteOn(byte channel, byte note, byte velocity)
{

  midiMsg(channel+0x90, note, velocity);
}
void midiMsg(byte cmd, byte data1, byte data2)
  {Serial.write(cmd);


  Serial.write(data1);
  Serial.write(data2);
  }

int count = 1;
unsigned long old_time = millis();
unsigned long new_time, dt, old_dt=100;
unsigned long period = 1000;
unsigned long t[4], dtAvg;
long sensorValue, prev_sensorValue = analogRead(A2), diff[4], diffval;

void acdc(int dt){
   noteOn(9, 44, 127);
   if(count==1)
     noteOn(9, 36, 127);
    if(count==3)
      noteOn(9, 38, 127);
   count++;

   delay(dt);
   if(count>4)
         count = 1;
   }

void setup() {
  Serial.begin(9600);
}


void loop() {

  int thresh = analogRead(A0);

  delay(1);
  prev_sensorValue = sensorValue;
  //Serial.println(prev_sensorValue);
  sensorValue = analogRead(A2);
  //Serial.print(sensorValue);
  //Serial.print(' ');

diff[0] = diff[1];
  diff[1] = diff[2];
  diff[2] = diff[3];
  diff[3] = diffval;

  dtAvg = (w1*diff[0] + w2*diff[1] + w3*diff[2] + w4*diff[3])/(w1+w2+w3+w4);
  if(sensorValue < 500){
        //Serial.println(diff);
        //Serial.println(sensorValue);
        new_time = millis();
        dt = new_time-old_time;
        if(dt>50 && dt<1000);

        old_time = new_time;


        }

  delay(1);
  if(dt>50 && dt<500){


  acdc(dt);
  }

   //OLD
    //noteOn(9, 40, 120);
    //Serial.println(dt);
    //delay(dt);
    //old_dt = dt;

    //else{
      //noteOn(9, 49, 120);
      //delay(old_dt);
    //}

  /*t[0] = t[1];
  t[1] = t[2];
  t[2] = t[3];
  t[3] = dt;

  dtAvg = (w1*t[0] + w2*t[1] + w3*t[2] + w4*t[3])/(w1+w2+w3+w4);
  if (dtAvg >50 && dtAvg < 600){ */
        //acdc(dtAvg);
        //}


}