#include <DHT.h>
#include <ThingSpeak.h>
#include <WiFi.h> // Use this for ESP32; for ESP8266, use <ESP8266WiFi.h>

// Replace these with your network credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Replace these with your ThingSpeak channel details
unsigned long channelID = ; // Replace with your ThingSpeak channel ID
const char* writeAPIKey = "MMN70WV92S98NICB"; // Replace with your ThingSpeak API key

// DHT Sensor settings
#define DHTPIN 15     // Digital pin connected to the DHT sensor
#define DHTTYPE DHT22 // Change this to DHT11 if you are using DHT11

DHT dht(DHTPIN, DHTTYPE);

// Ultrasonic sensor settings
#define TRIGGER_PIN  27
#define ECHO_PIN     14

WiFiClient client; // Create a WiFiClient object

void setup() {
  Serial.begin(115200);
  dht.begin();
  
  // Initialize WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi");

  // Initialize ThingSpeak
  ThingSpeak.begin(client);
  
  // Initialize ultrasonic sensor pins
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  // Read DHT sensor
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  
  // Check if any reads failed and exit early (to try again).
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Read Ultrasonic sensor
  long duration, distance;
  
  // Send a pulse to trigger
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
  
  // Read the echo pulse duration
  duration = pulseIn(ECHO_PIN, HIGH);
  
  // Calculate distance in cm
  distance = (duration / 2) / 29.1;

  // Print the results to Serial Monitor
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print(" °C\tHumidity: ");
  Serial.print(humidity);
  Serial.print(" %\tDistance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  // Send data to ThingSpeak
  ThingSpeak.setField(1, temperature);
  ThingSpeak.setField(2, humidity);
  ThingSpeak.setField(3, distance);
  
  // Write to ThingSpeak
  int x = ThingSpeak.writeFields(channelID, writeAPIKey);
  if(x == 200) {
    Serial.println("Data successfully sent to ThingSpeak");
  } else {
    Serial.println("Failed to send data to ThingSpeak");
  }
  
  // Wait 20 seconds before sending the next update
  delay(20000);
}