#define PIR_SENSOR 2  // PIR Sensor connected to Digital Pin 2
#define LED_PIN 9     // PWM LED pin
#define RELAY_PIN 8   // Relay pin for full light ON/OFF

int brightness = 0;  // Initial LED brightness
bool motionDetected = false;

void setup() {
    pinMode(PIR_SENSOR, INPUT);
    pinMode(LED_PIN, OUTPUT);
    pinMode(RELAY_PIN, OUTPUT);
    Serial.begin(9600);
}

void loop() {
    int motion = digitalRead(PIR_SENSOR);

    if (motion == HIGH) {
        Serial.println("Motion Detected! Increasing brightness...");
        motionDetected = true;
        digitalWrite(RELAY_PIN, HIGH);  // Turn ON full light (if using relay)

        // Gradually increase brightness
        for (brightness = 0; brightness <= 255; brightness += 5) {
            analogWrite(LED_PIN, brightness);
            delay(50);  // Smooth transition effect
        }

    } else {
        if (motionDetected) {
            Serial.println("No Motion. Dimming lights...");
            motionDetected = false;

            // Gradually decrease brightness
            for (brightness = 255; brightness >= 0; brightness -= 5) {
                analogWrite(LED_PIN, brightness);
                delay(50);
            }
            digitalWrite(RELAY_PIN, LOW);  // Turn OFF full light (if using relay)
        }
    }

    delay(500);  // Adjust sensitivity delay
}