#include "ThingSpeak.h"
#include <WiFi.h>

const int trigPin = 23; // Ultrasonic sensor trigger pin
const int echoPin = 22; // Ultrasonic sensor echo pin

const int redLedPin = 2;  // Red LED pin
const int greenLedPin = 4; // Green LED pin

unsigned long channelNumber = 2511458; // ThingSpeak channel number
const char *writeAPIKey = "NYRG5SVBNKQC8T3S"; // ThingSpeak write API key

char ssid[] = "Galaxy S21 FE 5G 3524";
char pass[] = "1234567811";

WiFiClient client;

long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);

  digitalWrite(redLedPin, LOW);
  digitalWrite(greenLedPin, LOW);

  Serial.begin(9600);

  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
  Serial.println("IP Address: ");
  Serial.println(WiFi.localIP());

  ThingSpeak.begin(client);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2; // Calculate distance in cm

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance <= 4) {
    digitalWrite(redLedPin, HIGH);
    digitalWrite(greenLedPin, LOW);
  } else {
    digitalWrite(redLedPin, LOW);
    digitalWrite(greenLedPin, HIGH);
  }

  // Update ThingSpeak channel every 10 seconds
  ThingSpeak.setField(1, distance);
  int response = ThingSpeak.writeFields(channelNumber, writeAPIKey);
  if (response == 200) {
    Serial.println("Data sent to ThingSpeak successfully!");
  } else {
    Serial.print("Error sending data to ThingSpeak. HTTP error code: ");
    Serial.println(response);
  }
  delay(10000); // Delay 10 seconds before next update
}