#include <DHT.h>

#define DHTPIN 2         // Pin connected to the DHT22
#define DHTTYPE DHT22    // DHT 22 (AM2302)
#define PUMPPIN 7        // Pin for Relay (controls the water pump)
#define BUZZERPIN 9      // Pin for Buzzer (alert)

DHT dht(DHTPIN, DHTTYPE);

int humidityThreshold = 40; // Humidity threshold below which pump and alert will activate

void setup() {
  Serial.begin(9600);
  
  // Initialize DHT sensor
  dht.begin();
  
  // Initialize Relay and Buzzer pins
  pinMode(PUMPPIN, OUTPUT);
  pinMode(BUZZERPIN, OUTPUT);
  
  // Ensure pump and buzzer are off initially
  digitalWrite(PUMPPIN, LOW);
  digitalWrite(BUZZERPIN, LOW);

  Serial.println("Smart Irrigation System Initialized.");
}

void loop() {
  // Read humidity
  float humidity = dht.readHumidity();

  // Check if reading is valid
  if (isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Print humidity to serial monitor
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  // Check if humidity is below threshold (indicating dry soil)
  if (humidity < humidityThreshold) {
    Serial.println("Soil is too dry. Activating pump and buzzer...");

    // Turn on the pump (via relay) and buzzer
    digitalWrite(PUMPPIN, HIGH);
    digitalWrite(BUZZERPIN, HIGH);
  } else {
    Serial.println("Soil moisture is sufficient. Pump and alert are off.");

    // Turn off the pump and buzzer
    digitalWrite(PUMPPIN, LOW);
    digitalWrite(BUZZERPIN, LOW);
  }

  // Wait before checking again
  delay(2000);
}