const int LDR_PIN = A0;   // LDR pin connected to analog pin A0
const int LED_PIN = 9;    // LED pin connected to digital pin 9

void setup() {
  pinMode(LDR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  int lightValue = analogRead(LDR_PIN); // Read the value from LDR
  if (lightValue > 500) { // Adjust this threshold according to your ambient light conditions
    digitalWrite(LED_PIN, HIGH); // Turn on LED when it's dark
  } else {
    digitalWrite(LED_PIN, LOW); // Turn off LED when it's bright
  }
  delay(100); // Delay for stability
}