#include "WiFi.h"

const char* ssid = "Wokwi-GUEST";
const char* password =  "";
const int redPin = 15;
const int yellowPin = 2;
const int greenPin = 4;
const int trigPin = 13;
const int echoPin = 12;
long duration;
int distance;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  Serial.println("Hello, ESP32!");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi..");
  }
  Serial.println("Connected to the WiFi network");
  // Print local IP address and start web server
  Serial.println("");
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  pinMode (redPin, OUTPUT);
  pinMode (yellowPin, OUTPUT);
  pinMode (greenPin, OUTPUT);
}

void loop() {
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);

  // Calculate the distance
  distance = (duration*0.034/2)+1;

  // Prints the distance in the Serial Monitor
  Serial.print("Distance (cm): ");
  Serial.println(distance);

  if(distance<=50){
    digitalWrite (greenPin, HIGH);	// turn on the LED
    Serial.println("Green light is on");
  }
  else {
    digitalWrite (greenPin, LOW);
  }
  if(distance>50&&distance<=150){
    digitalWrite (yellowPin, HIGH);	// turn on the LED
    Serial.println("Yellow light is on");
  }
  else{
    digitalWrite (yellowPin, LOW);
  }
  if(distance>150){
    digitalWrite (redPin, HIGH);	// turn on the LED
    Serial.println("Red light is on");
  }
  else {
    digitalWrite (redPin, LOW);
  }

  delay(1000);
}