#include <WiFi.h>
#include <ThingSpeak.h>
#include <DHT.h>
#include <LiquidCrystal_I2C.h>

#define DHTPIN 15     // Digital pin connected to the DHT sensor
#define DHTTYPE DHT22   // DHT 22  
#define TRIG_PIN 5   // The pin connected to the trigger of the ultrasonic sensor
#define ECHO_PIN 18  // The pin connected to the echo of the ultrasonic sensor
#define LED_PIN 2

// Initialize LCD (address 0x27, 16 characters, 2 lines)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Initialize DHT sensor.
DHT dht(DHTPIN, DHTTYPE);

// Replace with your network credentials and ThingSpeak channel details
const char* ssid = "Wokwi-GUEST";
const char* password = "";
unsigned long myChannelNumber = 2723081;
const char * myWriteAPIKey = "R9UH41QTB8DOOLMI";

WiFiClient client;

void setup() {
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  dht.begin();
  WiFi.begin(ssid, password);
  Serial.println("Connecting");
  while(WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  ThingSpeak.begin(client);

  // Initialize the ultrasonic sensor pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}
  
void loop() {
  // Read data from DHT sensor
  float h = dht.readHumidity();
  float t = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit

  // Read distance from ultrasonic sensor
  long duration, distance;
  digitalWrite(TRIG_PIN, LOW);  
  delayMicroseconds(2); 
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10); 
  digitalWrite(TRIG_PIN, LOW); 
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;

  // Send data to ThingSpeak
  if (WiFi.status()== WL_CONNECTED){
    ThingSpeak.setField(1, t); // Send temperature to field 1
    ThingSpeak.setField(2, h); // Send humidity to field 2
    ThingSpeak.setField(3, distance); // Send distance to field 3
    int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
    if(x == 200){
      Serial.println("Channel update successful.");
    }
    else{
      Serial.println("Problem updating channel. Please try again.");
    }
  }

// Display temperature, humidity, and distance on the LCD
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(t);
  lcd.print(" C");

  lcd.setCursor(0, 1);
  lcd.print("Hum: ");
  lcd.print(h);
  lcd.print(" %");

  delay(1000);  // Delay for readability

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Dist: ");
  lcd.print(distance);
  lcd.print(" cm");

  delay(1000);  // Delay before next reading

  // Control LED based on distance (adjust threshold as needed)
  if (distance < 20) {
    digitalWrite(LED_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW);
  }

  delay(2000);

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.println(" %");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println(" *C");
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  Serial.print("send to Thingspeak");
}