Smart Agricultural Monitoring

#include <DHT.h>

// Define sensor pins
#define DHTPIN 12       // DHT sensor data pin
#define DHTTYPE DHT11   // DHT sensor type
#define LDR_PIN A0      // LDR sensor analog pin
#define SOIL_SENSOR A1  // Soil moisture sensor analog pin
#define RELAY_PIN 13    // Relay for Motor control (Pump)
#define BUZZER 9        // Buzzer pin

// LED Indicators
#define RED_LED 3       // Dry Soil
#define GREEN_LED 4     // Moderate Moisture
#define YELLOW_LED 5    // Wet Soil
#define TEMP_LED 6      // High Temperature
#define LIGHT_LED 7     // Light Condition

DHT dht(DHTPIN, DHTTYPE);

void setup() {
    Serial.begin(9600);
    dht.begin();
    
    pinMode(LDR_PIN, INPUT);
    pinMode(SOIL_SENSOR, INPUT);
    pinMode(RELAY_PIN, OUTPUT);
    pinMode(BUZZER, OUTPUT);
    pinMode(RED_LED, OUTPUT);
    pinMode(YELLOW_LED, OUTPUT);
    pinMode(GREEN_LED, OUTPUT);
    pinMode(TEMP_LED, OUTPUT);
    pinMode(LIGHT_LED, OUTPUT);
    
    digitalWrite(RELAY_PIN, HIGH); // Relay OFF initially (Active LOW)
}

void loop() {
    float temp = dht.readTemperature();
    float humidity = dht.readHumidity();

    if (isnan(temp) || isnan(humidity)) {
        Serial.println("DHT sensor error!");
        return;
    }

    int lightValue = analogRead(LDR_PIN);
    int soilValue = 1023 - analogRead(SOIL_SENSOR);

    Serial.print("Temp: "); Serial.print(temp);
    Serial.print("C  Humidity: "); Serial.print(humidity);
    Serial.print("%  Light: "); Serial.print(lightValue);
    Serial.print("  Soil Moisture: "); Serial.println(soilValue);

    // Soil Moisture Control
    if (soilValue < 300) {  
        digitalWrite(RED_LED, HIGH);
        digitalWrite(YELLOW_LED, LOW);
        digitalWrite(GREEN_LED, LOW);
        digitalWrite(RELAY_PIN, HIGH);
        digitalWrite(BUZZER, HIGH);
        delay(500);
        digitalWrite(BUZZER, LOW);
    } 
    else if (soilValue < 700) {  
        digitalWrite(RED_LED, LOW);
        digitalWrite(GREEN_LED, HIGH);
        digitalWrite(YELLOW_LED, LOW);
        digitalWrite(RELAY_PIN, LOW);
    } 
    else {  
        digitalWrite(RED_LED, LOW);
        digitalWrite(GREEN_LED, LOW);
        digitalWrite(YELLOW_LED, HIGH);
        digitalWrite(RELAY_PIN, LOW);
        tone(BUZZER, 2050);
        delay(500);
        noTone(BUZZER);
    }

    // Temperature Alert
    if (temp > 35) { 
        digitalWrite(TEMP_LED, HIGH);
        digitalWrite(BUZZER, HIGH);
        delay(500);
        digitalWrite(BUZZER, LOW);
    } else {
        digitalWrite(TEMP_LED, LOW);
    }

    // Light Condition
    digitalWrite(LIGHT_LED, lightValue > 800 ? LOW : HIGH);

    delay(2000);
}