#include "pitches.h"
#include <Buzzer.h>
// Ultrasonic Sensor Code
const int trigPin = 12;
const int echoPin = 10;
long duration;
int distance;

//Speaker code
int melody[] = {NOTE_A4, NOTE_B4, NOTE_C3, NOTE_A4, NOTE_B4, NOTE_C3}; // notes in the melody
int thisNote; int noteDuration; int pauseBetweenNotes;
int noteDurations[] = { 4, 8, 8, 4, 4, 4, 4, 4}; // note durations: 4 = quarter note, 8 = eighth note, etc.:,

//PIR Code
int Pirsensor = 8; //the pin that the sensor is attached to
int PirState = LOW; //default to show no motion detected
int sensorvalue; //to store sensor status

//Thermistor Code
int ThermistorPin = A0;
int Vo;
float R1 = 100000;
float logR2, R2, T;
float c1 = 1.009249522e-03, c2 = 2.378405444e-04, c3 = 2.019202697e-07;

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

  //Ultrasonic sensor code
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input

  //Speaker Code
  for (thisNote = 0; thisNote < 8; thisNote++) // iterate over the notes of the melody:
  {
    // to calculate the note duration, take one second divided by the note type.
    //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
    noteDuration = 1000 / noteDurations[thisNote];
    // to distinguish the notes, set a minimum time between them, the note's duration + 30% seems to work well:
    pauseBetweenNotes = noteDuration * 1.30;
  }

  //PIR Code
  pinMode(Pirsensor, INPUT);
}


void loop()
{
  //Ultrasonic Sensor Code
  digitalWrite(trigPin, LOW);// Clears the trigPin
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);// Sets the trigPin on HIGH state for 10 micro seconds
  delay(500);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);// Reads the echoPin, returns the sound wave travel time in microseconds
  distance = duration * 0.034 / 2;  // Calculating the distance

  //PIR Code
  sensorvalue = digitalRead(Pirsensor);//read signal from sensor

  //Thermistor Code
  Vo = analogRead(ThermistorPin);
  R2 = R1 * (1023.0 / (float)Vo - 1.0);
  logR2 = log(R2);
  T = (1.0 / (c1 + c2 * logR2 + c3 * logR2 * logR2 * logR2));//Temp in kelvins
  T = T - 273.15;//Temp in degree celcius


  //Use Ultrasonic sensor to activate system
  if (distance <= 20) //reverse is the case, but i am adjusting for the Ultrasonic sensor sensitivity
  {
    Serial.print("Distance = ");
    Serial.println(distance);
    Serial.println("Driver out of car, check for movement and temperature!!!!!");

    if (sensorvalue == HIGH)// check for movement inside the car
    {
      //Turn Speaker ON
      tone(3, melody[thisNote], noteDuration);
      delay(pauseBetweenNotes);
      noTone(3); noTone(3); // stop the tone playing:
      Serial.println("Motion detected!");
      Serial.print("Temperature: ");
      Serial.print(T);
      Serial.print('\n');
      delay(500);
    }

    //Multiconditional code, to check that there's movement and the car is hot.
    if (sensorvalue == HIGH && T > 24)// check if there's movement and high temperature
    {
      //Turn Speaker ON
      tone(3, melody[thisNote], noteDuration);
      delay(pauseBetweenNotes);
      noTone(3); noTone(3); // stop the tone playing:
      Serial.println("Motion detected! Hot Car Emergency!!!");
      Serial.print("Temperature: ");
      Serial.print(T);
      Serial.print('\n');
      delay(500);                // delay 500 milliseconds
    }

  }

  else
  {
    Serial.print("Distance: ");
    Serial.println(distance);
    Serial.println("Driver Inside car, all good");
    delay(500);
  }

  delay(1000);