#include "Adafruit_NeoPixel.h"
#include <Wire.h>

#define DEBUG  0

// Pin definitions for the 74HC164 SIPO shift register (drives button rows high)
#define DATAPIN      5 
#define CLOCKPIN     7

// digital LEDS
#define PIN 12
#define NUM_LEDS    8

#define AWAKE    11

#define POWER_ON    10

// variables for the sensors
//#define THRESHOLD       15
#define THRESHOLD       15
#define SCANTIME        1500
//#define MASKTIME        60
#define MASKTIME        50
#define RETRIGTIME      100

//#define VERYVERYFASTADC 1

// defines for setting and clearing register bits
//#ifndef cbi
//#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
//#endif
//#ifndef sbi
//#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
//#endif

// Define various ADC prescaler
const unsigned char PS_16 = (1 << ADPS2);
const unsigned char PS_32 = (1 << ADPS2) | (1 << ADPS0);
const unsigned char PS_64 = (1 << ADPS2) | (1 << ADPS1);
const unsigned char PS_128 = (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);



float sensorValue[8] = { 
  0, 0, 0, 0, 0, 0, 0, 0};  // variable to store the value coming from the sensor

float sensorValueAnt[8] = { 
  0, 0, 0, 0, 0, 0, 0, 0};  // variable to store the value coming from the sensor anterior

int sensorPin[8] = { 
  A1, A7, A2, A6, A3, A5, A4, A8};

int dischargePin[8] = { 
  0, 6, 1, 5, 2, 4, 3, 7};

int mapled[8] = { 
  0, 6, 1, 5, 2, 4, 3, 7};

unsigned long  time[8] = { 
  0, 0, 0, 0, 0, 0, 0, 0};

boolean  state[8] = { 
  true, true, true, true, true, true, true, true };

Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, PIN, NEO_GRB + NEO_KHZ800);


void setup() {

  // 164 Setup
  pinMode(DATAPIN, OUTPUT);
  pinMode(CLOCKPIN, OUTPUT); 
  pinMode(POWER_ON , OUTPUT); 
  pinMode(AWAKE, OUTPUT);
  digitalWrite(AWAKE, HIGH); 
  digitalWrite(POWER_ON,LOW); 
  strip.begin(); // Initialization of led matrix
  strip.setPixelColor(0, 0, 0, 0);
  strip.show();
  
  Serial1.begin(9600);
//  delay(500);
//  Serial1.print(F("$$$"));
//  delay(500);
//  Serial1.println();
//  Serial1.print(F("$$$"));
//  delay(500);
//  Serial1.println();
//  Serial1.println(F("sleep"));
//  
//  digitalWrite(AWAKE, LOW); 
  
// // set prescale to 16
// sbi(ADCSRA,ADPS2) ;
// cbi(ADCSRA,ADPS1) ;
// cbi(ADCSRA,ADPS0) ;
// 
// // set prescale to 8
// cbi(ADCSRA,ADPS2) ;
// sbi(ADCSRA,ADPS1) ;
// sbi(ADCSRA,ADPS0) ;
// 
   // set prescale to 4
//   cbi(ADCSRA,ADPS2) ;
//   sbi(ADCSRA,ADPS1) ;
//   cbi(ADCSRA,ADPS0) ;
  
  // set up the ADC
  ADCSRA &= ~PS_128;  // remove bits set by Arduino library
  // you can choose a prescaler from above.
  // PS_16, PS_32, PS_64 or PS_128
  //ADCSRA |= PS_64;    // set our own prescaler to 64 
  ADCSRA |= PS_32;    // set our own prescaler to 64 

  if(DEBUG)
    Serial.begin(115200);

}

void loop() {


  for (int i = 0; i<8; i++) 
  { 

    sensorValue[i] = analogRead(sensorPin[i]);  

    if (( ( sensorValue[i]>THRESHOLD ) && state[i] ) ) //|| ( (sensorValue[i]>(sensorValueAnt[i]/3) ) && ( (millis()-time[i])>(MASKTIME+SCANTIME) ) && ( (millis()-time[i])<=RETRIGTIME ) ) )  // superado el umbral y estado listo para samplear
    {

//      while (analogRead(sensorPin[i])>sensorValue[i]) { /*delayMicroseconds(100);*/ sensorValue[i] = analogRead(sensorPin[i]); }  
//      while (average(sensorPin[i])>sensorValue[i]) { /*delayMicroseconds(100);*/ sensorValue[i] = average(sensorPin[i]); }  
      delayMicroseconds(SCANTIME); // sustituir por un detector de nivel maximo durante una ventana temporal
//
//      sensorValue[i] = average(sensorPin[i]);  
      sensorValue[i] = analogRead(sensorPin[i]);  
      
      if(sensorValue[i]>THRESHOLD)
      {
        if(DEBUG)
          {
            Serial.print("ON Sensor");
            Serial.print(i);
            Serial.print(": ");
            Serial.print((sensorValue[i]*5)/1.023);
            Serial.print("mV");
            Serial.print(" Time: ");
            Serial.print(millis()-time[i]);
            Serial.println("ms");
          }
        
        if (state[i]) time[i] =millis();
        state[i] = false;

        MIDIEvent e1 = {  0x09, 0x90, 60+i, constrain(sensorValue[i]/2, 0, 127) }; // aplicar curvas de log y exp
        MIDIUSB.write(e1);

        //int Value = sensorValue[i]*8;
        //if ((Value>341)&(Value<=682)) strip.setPixelColor(mapled[i], 0, map(Value,342, 682, 0, 255), 0);
        //else if(Value>682) strip.setPixelColor(mapled[i], 0, 0,map(Value, 883, 1023, 0, 255));
        //else strip.setPixelColor(mapled[i], map(Value, 0, 341, 0, 255), 0, 0);        
        //strip.show();


        //sensorValueAnt[i]=sensorValue[i];

      }
    }

    if(((millis()-time[i]) > MASKTIME ) && !state[i] )
    {
      state[i] = true;
      MIDIEvent e2 = { 0x09, 0x90, 60+i, 0  };
      MIDIUSB.write(e2);    
      
      if(DEBUG)
      {
        Serial.print("OFF Sensor");
        Serial.print(i);
        Serial.println();
      }
      
      ShiftWrite(dischargePin[i], HIGH);
      ShiftWrite(dischargePin[i], LOW);
    }
  }


}


float average(int anaPin) {
  int lecturas = 4;
  long total = 0;
  float average = 0;
  for(int i=0; i<lecturas; i++)
  {
    //delay(1);
    total = total + analogRead(anaPin);
  }
  average = (float)total / lecturas;  
  return(average);
}


uint8_t val_shift = 0x00; //Valor del shift register
void ShiftWrite(uint8_t pin, boolean state){
  bitWrite(val_shift, pin, state);
  shiftOut(DATAPIN, CLOCKPIN, MSBFIRST, val_shift);
}



//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//    USECURVE beta version
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
byte UseCurve(byte Curve,int Value,byte Form)
{
  int ret=0;
  if(Curve==0) { ret=((Value*Form)>>3); if(ret>=127) return 127; return ret;}
  
  float x=(float)Value;
  float f=((float)Form)/128.0;

  switch(Curve)
  {
    //[0-1023]x[0-127]
    case 1: ret=(127.0/(exp(2.0*f)-1))*(exp(f*x/512.0)-1.0);break; //Exp 4*(exp(x/256)-1)
    case 2: ret=log(1.0+(f*x/128.0))*(127.0/log((8*f)+1));break; //Log 64*log(1+x/128)
    case 3: ret=(127.0/(1.0+exp(f*(512.0-x)/64.0)));break; //Sigma
    case 4: ret=(64.0-((8.0/f)*log((1024/(1+x))-1)));break; //Flat
  }
  if(ret<=0) return 0;
  if(ret>=127) return 127;//127
  return ret;
}