#include <Arduino.h>
#include <WiFi.h>
#include <ThingSpeak.h>
const char* ssid = "Wokwi-GUEST";
const char* pass = ""; 
const unsigned long myChannelNumber = 3043754;
const char* myWriteAPIKey = "YI5QD5ZPKZV2823C"; 
int led=18,trigPin=5,echoPin=19,ldr=17;
float pingTime,targetDistance;
WiFiClient client;
void setup() {
  Serial.begin(9600);
  pinMode(led, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(ldr, INPUT);
  pinMode(echoPin, INPUT);
}
void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("Attempting to connect to WiFi...");
    while (WiFi.status() != WL_CONNECTED) {
      WiFi.begin(ssid, pass);
      Serial.print(".");
      delay(5000);
  }
    Serial.println("\nConnected.");
  }
  int ldrPin=digitalRead(ldr);
  digitalWrite(trigPin, LOW); 
  delayMicroseconds(2); 
  digitalWrite(trigPin,  HIGH); 
  delayMicroseconds(10); 
  digitalWrite(trigPin, LOW); 
  delayMicroseconds(15);  
  pingTime = pulseIn(echoPin, HIGH); 
  targetDistance = (pingTime*0.0343)/2; 
  Serial.print("Distance: ");
  Serial.print(targetDistance);
  Serial.println(" cm");
  Serial.print("LDR Value: ");
  Serial.println(ldrPin);
  if((targetDistance <=100)&&(ldrPin == 0 )) {
    digitalWrite(led, HIGH);
  }
  else {
    digitalWrite(led, LOW);
  }
  ThingSpeak.begin(client);
  ThingSpeak.setField(1, ldrPin);
  int statusCode = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
  if (statusCode == 200) {
    Serial.println("Channel update successful.");
  } 
  else {
    Serial.print("Problem writing data. HTTP error code:");
    Serial.println(statusCode);
  }
  delay(15000);
}