#include <Adafruit_NeoPixel.h>

int laserPin = 4;
int doorsensorpin = 8; // limit switch NC pin
int doorsensorled = 7; // door open led
bool havemotion = false;
int checksaftersafe = 0;
#define echoPin 3 // attach pin D2 Arduino to pin Echo of HC-SR04
#define trigPin 2 //attach pin D3 Arduino to pin Trig of HC-SR04

#define LED_PIN     5
#define NUM_LEDS    7
Adafruit_NeoPixel pixels(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

// defines variables
long duration; // variable for the duration of sound wave travel
int distance; // variable for the distance measurement
int dooropen; // variable for the limit switch value

void setup() {
  // put your setup code here, to run once:
  pinMode(laserPin, OUTPUT);
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT  
  pinMode(doorsensorpin, INPUT_PULLUP);
  pinMode(doorsensorled, OUTPUT);
  pinMode(13, OUTPUT);
  pixels.begin();  
  //Serial.begin(9600); 
  digitalWrite(laserPin,LOW);
  digitalWrite(doorsensorled,LOW);
  digitalWrite(13,LOW);
}

void loop() {

  pixels.clear();
  pixels.setBrightness(200);
  
  // put your main code here, to run repeatedly:
  // Clears the trigPin condition
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // reads is the door open limit switch
  dooropen = digitalRead(doorsensorpin);
  // Calculating the distance
  distance = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
  // Displays the distance on the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  // distance from garage to sensor in most cases is: 46cm (21 inches minus 3 inches for box width)
  // but we will go with 60... just in case, since initial tests seemed to be a bit off.
  if (distance < 60)
  {
    havemotion = true;
    checksaftersafe = 0;
    digitalWrite(laserPin, HIGH);
    for( int i = 0; i < NUM_LEDS; i++) {
      pixels.setPixelColor(i, pixels.Color(255, 0, 0));
    }
  }
  else
  {
    // 20 times would be about 10 seconds of safety
    if (havemotion && checksaftersafe < 20)
    {
      for( int i = 0; i < NUM_LEDS; i++) {
        pixels.setPixelColor(i, pixels.Color(0, 255, 0));
      }
      checksaftersafe++;
    }
    else
    {
      for( int i = 0; i < NUM_LEDS; i++) {
        pixels.setPixelColor(i, pixels.Color(0, 0, 255));
      }
      checksaftersafe = 0;
      havemotion = false;    
    }
    digitalWrite(laserPin, LOW);
  }

  // now lets do the door open limit switch logic
  if (dooropen == HIGH)
  {
    Serial.println("Door closed");
    digitalWrite(doorsensorled, LOW);
  }
  else
  {
    Serial.println("Door open");
    digitalWrite(doorsensorled, HIGH);
  }

  pixels.show();
  delay(250);
}