const int PIR_PIN = 4;  
const int LDR_PIN = A0;  
const int LED_PIN = 6;  

int pirState = LOW;     
int ldrValue = 0;        
int threshold = 500;    
void setup() {
  pinMode(PIR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // Read PIR sensor state
  pirState = digitalRead(PIR_PIN);
  // Read LDR sensor value
  ldrValue = analogRead(LDR_PIN);

  // Check if motion is detected and ambient light level is below threshold
  if (pirState == HIGH && ldrValue < threshold) {
    // Turn on the LED
    digitalWrite(LED_PIN, HIGH);
    Serial.println("Motion detected and ambient light level is low. Turning on LED.");
  } else {
    // Turn off the LED
    digitalWrite(LED_PIN, LOW);
    Serial.println("No motion detected or ambient light level is high. Turning off LED.");
  }
  delay(100);
}