int ldrPin = A0; // LDR connected to analog pin A0
int ledPin = 9; // LED connected to digital pin 9
int ldrValue = 0; // Variable to store LDR value
int threshold = 500; // Light level threshold (adjust as needed)
void setup() {
Serial.begin(9600); // Start serial communication
pinMode(ledPin, OUTPUT); // Set LED pin as output
}
void loop() {
ldrValue = analogRead(ldrPin); // Read LDR value (0–1023)
Serial.print("Light Intensity: ");
Serial.println(ldrValue);
// Control LED
if (ldrValue < threshold) {
digitalWrite(ledPin, HIGH); // Turn LED ON when dark
} else {
digitalWrite(ledPin, LOW); // Turn LED OFF when bright
}
delay(500); // Small delay for readability
}