//***Sample code for frequency detection**/
//generalized wave freq detection with 38.5kHz sampling rate and interrupts
//http://www.instructables.com/id/Arduino-Frequency-Detection/

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
*/

#include <Time.h> //so you can detect the time between snores later

//clipping indicator variables
boolean clipping = 0;

//data storage variables
byte newData = 0;
byte prevData = 0;
unsigned int time = 0;//keeps time and sends vales to store in timer[] occasionally
int timer[10];//sstorage for timing of events
int slope[10];//storage for slope of events
unsigned int totalTimer;//used to calculate period
unsigned int period;//storage for period of wave
byte index = 0;//current storage index
float frequency;//storage for frequency calculations
int maxSlope = 0;//used to calculate max slope as trigger point
int newSlope;//storage for incoming slope data

//variables for decided whether you have a match
byte noMatch = 0;//counts how many non-matches you've received to reset variables if it's been too long
byte slopeTol = 3;//slope tolerance- adjust this if you need
int timerTol = 10;//timer tolerance- adjust this if you need

//variables for amp detection
unsigned int ampTimer = 0;
byte maxAmp = 0;
byte checkMaxAmp;
byte ampThreshold = 30;//raise if you have a very noisy signal

int count = 0;  //number of seconds to vibrate!
boolean startOver = true;  //starts detecting snores again
boolean motorOn = false;  //start vibe motors as off
time_t start;

void setup(){
  
  Serial.begin(9600);
  
  pinMode(5,OUTPUT);//output pin
  
  cli();//diable interrupts
  
  //set up continuous sampling of analog pin 0 at 38.5kHz
 
  //clear ADCSRA and ADCSRB registers
  ADCSRA = 0;
  ADCSRB = 0;
  
  ADMUX |= (1 << REFS0); //set reference voltage
  ADMUX |= (1 << ADLAR); //left align the ADC value- so we can read highest 8 bits from ADCH register only
  
  ADCSRA |= (1 << ADPS2) | (1 << ADPS0); //set ADC clock with 32 prescaler- 16mHz/32=500kHz
  ADCSRA |= (1 << ADATE); //enabble auto trigger
  ADCSRA |= (1 << ADIE); //enable interrupts when measurement complete
  ADCSRA |= (1 << ADEN); //enable ADC
  ADCSRA |= (1 << ADSC); //start ADC measurements
  
  sei();//enable interrupts
}

ISR(ADC_vect) {//when new ADC value ready
  
  //PORTB &= B11101111;//set pin 12 low
  prevData = newData;//store previous value
  newData = ADCH;//get value from A0
  if (prevData < 127 && newData >=127){//if increasing and crossing midpoint
    newSlope = newData - prevData;//calculate slope
    if (abs(newSlope-maxSlope)<slopeTol){//if slopes are ==
      //record new data and reset time
      slope[index] = newSlope;
      timer[index] = time;
      time = 0;
      if (index == 0){//new max slope just reset
        //PORTB |= B00010000;//set pin 12 high
        noMatch = 0;
        index++;//increment index
      }
      else if (abs(timer[0]-timer[index])<timerTol && abs(slope[0]-newSlope)<slopeTol){//if timer duration and slopes match
        //sum timer values
        totalTimer = 0;
        for (byte i=0;i<index;i++){
          totalTimer+=timer[i];
        }
        period = totalTimer;//set period
        //reset new zero index values to compare with
        timer[0] = timer[index];
        slope[0] = slope[index];
        index = 1;//set index to 1
        //PORTB |= B00010000;//set pin 12 high
        noMatch = 0;
      }
      else{//crossing midpoint but not match
        index++;//increment index
        if (index > 9){
          reset();
        }
      }
    }
    else if (newSlope>maxSlope){//if new slope is much larger than max slope
      maxSlope = newSlope;
      time = 0;//reset clock
      noMatch = 0;
      index = 0;//reset index
    }
    else{//slope not steep enough
      noMatch++;//increment no match counter
      if (noMatch>9){
        reset();
      }
    }
  }
    
  if (newData == 0 || newData == 1023){//if clipping
    //PORTB |= B00100000;//set pin 13 high- turn on clipping indicator led
    clipping = 1;//currently clipping
  }
  
  time++;//increment timer at rate of 38.5kHz
  
  ampTimer++;//increment amplitude timer
  if (abs(127-ADCH)>maxAmp){
    maxAmp = abs(127-ADCH);
  }
  if (ampTimer==1000){
    ampTimer = 0;
    checkMaxAmp = maxAmp;
    maxAmp = 0;
  }
  
}

void reset(){//clean out some variables
  index = 0;//reset index
  noMatch = 0;//reset match counter
  maxSlope = 0;//reset slope
}


void checkClipping(){//manage clipping indicator LED
  if (clipping){//if currently clipping
    //PORTB &= B11011111;//turn off clipping indicator led
    clipping = 0;
  }
}


void loop(){
  
  checkClipping();
  
  if (checkMaxAmp>ampThreshold){
    frequency = 38462/float(period);//calculate frequency timer rate/period
  
    //print results
  }
  
  delay(100);
  
  //snoring stuff starts here
  //diana sun
  if (frequency <= 800 && frequency >= 50 && newData >= 25) //if its between thess freq & greater than this loudness,
  {                                                         //then snoring has been detected
    if (startOver)
    {
      start = now(); //start count of snore time
      startOver = false;
    } 
    if (now() - start >= 1) // if the snore sound has persisted within a 1 sec time frame,
    {
      Serial.println("Snoring detected");
      count = 20; //vibrates for 2 seconds after snoring is detected
      digitalWrite(5,HIGH); //turn on vibe motors
      motorOn = true;  //it is on now
    }
  }
  if (count > 0)
  {
     count = count - 1; //counts down the time
  }
  else if(motorOn) //if it has been on already
  {
     motorOn = false;  //it will remain false until snores are detected again
     startOver = true;  //start over the detection for snores
     digitalWrite(5, LOW); //turn off the vibe motors
  }
}