#include <Wire.h> //include the wire object and set a variable h to represent
#define SLAVE_ADDRESS 0x40 // slave address for the connection to your pi
char ADC_Convert[8]; //To store the data of the ADC in the array so that it can be passed to the pi
char DArray[8]; //To store the data of distance in the array so that it can be passed to the pi
int AVERAGING_LOOP_SIZE = 100;
int READ_PIN = 0;  // Analogue pin for SharpIR sensor
int DISTANCE_BUFFER = 1; //cm
int MIN_DISTANCE = 7; // minimum distance that the sensor can record. in cm
int MAX_DISTANCE = 60; // maximum distance that the sensor can record in cm
int IGNORE_BUFFER_THRESHHOLD = 35; // Readings
int thisDistance, lastDistance, ignoreBuffer, val; //decaring variables thisDistance(Distance) val(ADC value)
String thisPrint, lastPrint; //declaring variables for printing the output
int groundpin = 0; // write 0 to get ground
int greenpin = 12; // select the pin for the green LED RGB
int redpin = 13; // select the pin for the red LED RGB
int DO = 2; //Pin for Digital Output - DO for sound sensor
int DA = 3; // Pin for Analog Output - AO for sound sensor
int threshold = 30;//Set minimum threshold for LED lit
int sensorvalue = 0;



void setup() {
  pinMode(READ_PIN, INPUT);
  pinMode(DA,INPUT);
  pinMode (redpin, OUTPUT);// for distance
  pinMode (greenpin, OUTPUT);// for distance
  pinMode (groundpin, OUTPUT);// for distance
  digitalWrite (groundpin, LOW);
  pinMode(7, OUTPUT);// led light for sound
  Serial.begin(9600);
  Wire.begin(SLAVE_ADDRESS);
  ignoreBuffer = 0;
}

void loop() {
  sensorvalue = analogRead(DA);  //Read the analog value for sound
  Serial.print(" Sound Analog: ");
  Serial.print(sensorvalue);  //Print the analog value
  Serial.print("  ");
  Serial.print("Digital: ");
  Serial.print(digitalRead(DO));  //Print the digital value
  if (sensorvalue >= threshold) { //Compare analog value with threshold
    digitalWrite(7, HIGH);
  }
  else{
    digitalWrite(7,LOW);// off sound led
  }
  distance_loop();
}

void distance_loop(){
  delay(10);
  int adc = analogRead(READ_PIN);
   val = 0;
  // Averaging Loop
  for (int i = 0; i < AVERAGING_LOOP_SIZE ; i++) {
      val += analogRead(READ_PIN);
  }
  val = val / AVERAGING_LOOP_SIZE;
 
  
  thisDistance = (6762 / (val - 9)) - 4;

  if ((thisDistance < MIN_DISTANCE) || (thisDistance > MAX_DISTANCE))
  {
    thisPrint = "No Object";
    thisDistance=0;
    adc=0;
  }
  else if ((thisDistance < lastDistance + DISTANCE_BUFFER) || (thisDistance > lastDistance - DISTANCE_BUFFER))
  {
    ignoreBuffer ++;
    if (ignoreBuffer > IGNORE_BUFFER_THRESHHOLD) {
      thisPrint = "Object is now at: " + String(thisDistance) + "cm.";
      lastDistance = thisDistance;
      ignoreBuffer = 0;
    }
  }

  if (thisPrint != lastPrint) {
    Serial.println(thisPrint); //printing the distance
    Serial.println(val); //printing the ADC
    lastPrint = thisPrint;
  }

   if (thisDistance >=15 && thisDistance<=30) {
     //if distance is between 15cm and 30cm, it will light up the red led and turn off the green led
      digitalWrite(greenpin,LOW); 
      digitalWrite(redpin, HIGH);
    }
    
   if (thisDistance>=31 && thisDistance<=60) {
      //light up the green led and turn off the red led when the distance is between 31cm and 60cm
      digitalWrite(redpin,LOW);
      digitalWrite(greenpin, HIGH);
    }
    
   if (thisDistance<14 || thisDistance>60){
    //to turn off both the green led and red led when the distance is less than 14cm and more than 60cm
      digitalWrite(greenpin,LOW);
      digitalWrite(redpin,LOW);
    }
  
   Serial.println("Distance:"+thisDistance);

   
  dtostrf(adc, 4, 0, ADC_Convert); //converts the ADC value to string so that it can be passed to the pi
  dtostrf(thisDistance, 4, 1, DArray); //converts the Distance value to string so that it can be passed to the pi
  Wire.onRequest(sendDataToPi);  // calling the method sendDataToPi so that it will write the information to the pi
}

void sendDataToPi(){
  Wire.write(DArray); //writing the distance data to the pi
  Wire.write(ADC_Convert); //writing the ADC data to the pi
}