const int trigPin = 2; //the trig pin of the ultrasonic sensor; sends signal
const int echoPin = 4; //the echo pin of the ultrasonic sensor; detects signal

const int pirPin = 7; //the PIR sensor pin
int pirState = LOW; //basically means that the PIR sensor starts as low and detects no motion

const int buzzerPin = 8; //the buzzer has been connected to pin 8

const int redLED = 9; //the red LED; intensity can be controlled to change the colour emitted
int redBright = 0;    // how bright the LED is
int redFade = 5;    // how many points to fade the LED by

const int greenLED = 10; //the green LED; intensity can be controlled to change the colour emitted
int greenBright = 0;    // how bright the LED is
int greenFade = 5;    // how many points to fade the LED by

const int button = 13; //button to momentarily reset all the sensors back to normal

void setup() {

  pinMode(echoPin, INPUT);
  pinMode(pirPin, INPUT);
  pinMode(button, INPUT);
    
  pinMode(trigPin, OUTPUT);
  pinMode(redLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  
  Serial.begin(9600); // initialize serial communication at 9600 bits per second
}

void distance() {
  
  long durationInDigit;
  long distanceInInches;
  
  digitalWrite (trigPin, LOW); //set this to LOW to start with
  delayMicroseconds(2); //delay in microseconds between different commands
  digitalWrite (trigPin, HIGH); //here, the trig pin sends signals or vibrations to be detected
  delayMicroseconds(10);
  digitalWrite (trigPin, LOW); //set the the trig pin back to low
  
  durationInDigit = pulseIn(echoPin, HIGH); 
  distanceInInches = durationInDigit/74/2;
  
  Serial.println(distanceInInches);

    if (distanceInInches > 15 && distanceInInches < 30) {
      digitalWrite(greenLED, HIGH);
      digitalWrite(redLED, LOW);
    }
  
    if (distanceInInches < 10) {
      digitalWrite(redLED, HIGH);
      digitalWrite(greenLED, LOW);
    }
    
    if (distanceInInches > 10 && distanceInInches < 15){
      digitalWrite(redLED, LOW);
      digitalWrite(greenLED, LOW);
    }

    if (distanceInInches < 5) {
      digitalWrite(redLED, HIGH);
      tone(8, 250, 2000);
      digitalWrite(greenLED, 0);
    }
    
    if (distanceInInches > 5 && distanceInInches < 10){
      digitalWrite(redLED, HIGH);
      digitalWrite(buzzerPin, 0);
      digitalWrite(greenLED, 0);
    }
 
    if (distanceInInches > 30 || distanceInInches < 0){
      Serial.println("Distance Incalculable");
    }
    
  delay(500);

}

void reset() {
  if (digitalRead(button), HIGH);
   digitalWrite(pirState, LOW);
   digitalWrite(redLED, LOW);
   digitalWrite(greenLED, HIGH);
   digitalWrite(buzzerPin, 0);
   //digitalWrite(echoPin, 0);
}
        
void loop() {
  
  distance();
  
  int pirState = digitalRead(pirPin);
  
  if (pirState==1) {
    Serial.println("Motion Detected!!!");
    digitalWrite(greenLED, LOW);
    digitalWrite(redLED, HIGH);
    digitalWrite(buzzerPin, 1);
    delay(500);
  }
      
  if (pirState==0) {
    Serial.println("Detecting...");
    digitalWrite(greenLED, HIGH);
    digitalWrite(redLED, LOW);
    digitalWrite(buzzerPin, 0);
    delay(500);
      }

}