//Photo_diode_and_proximity_sensor const int pir = 8; // passive infared sensor const int ledPin = 12; const int lres = 0; // light resistor void setup() { pinMode(pir, INPUT); pinMode(ledPin, OUTPUT); pinMode(lres, INPUT); Serial.begin(9600); } void loop() { //read pir for movement int i = digitalRead(pir); Serial.println(i); //analog read lres int val = analogRead(lres); val = constrain (val, 0, 600); int ledval = map(val, 0, 600, 0, 255); //Serial.println(ledval); if (ledval >= 200 && i == HIGH) //if the room is dark and movement is detected { digitalWrite(ledPin, HIGH); delay(18000); } else { digitalWrite(ledPin, LOW); } }