void setup() { pinMode(13, OUTPUT);// photoresistor Serial.begin(9600); } void loop(){ if(analogRead(0) < 900){ tone (9, 4000); delay(200); tone(9, 3000); delay(200); tone (9, 4000); delay(200); tone(9, 3000); delay(200); tone (9, 4000); delay(200); tone(9, 3000); delay(200); tone (9, 4000); delay(200); tone(9, 3000); delay(200); tone (9, 4000); delay(200); tone(9, 3000); delay(200); tone (9, 4000); delay(200); tone(9, 3000); delay(200); } else{ noTone (9); Serial.println(analogRead(0)); } }