Features: GP2Y1010AU0F is a dust sensor by optical sensing system An infrared emitting diode (IRED) and an phototransistor are diagonally arranged into this device It detects the reflected light of dust in air. Especially, it is effective to detect very fine particle like the cigarette smoke In addition it can distinguish smoke from house dust by pulse pattern of output voltage Compact, thin package (46.0 × 30.0 × 17.6 mm) Low consumption current (Icc: MAX. 20 mA) The presence of dust can be detected by the photometry of only one pulse Enable to distinguish smoke from house dust Lead-free and RoHS directive compliant Compliant with RoHS directive (2002/95/EC) Detection Principle The principle is as follows, the sensor has a hole that allows air to freely flow through the directional LED light emitted by detecting dust refraction of light through the air after the dust to determine the content. Use the test code: int dustPin=0; float dustVal=0; int ledPower=2; int delayTime=280; int delayTime2=40; float offTime=9680; void setup(){ Serial.begin(9600); pinMode(ledPower,OUTPUT); pinMode(dustPin, INPUT); } void loop(){ // ledPower is any digital pin on the arduino connected to Pin 3 on the sensor digitalWrite(ledPower,LOW); delayMicroseconds(delayTime); dustVal=analogRead(dustPin); delayMicroseconds(delayTime2); digitalWrite(ledPower,HIGH); delayMicroseconds(offTime); delay(1000); if (dustVal>36.455) Serial.println((float(dustVal/1024)-0.0356)*120000*0.035); Date & Air quality 3000 + = very bad 1050-3000 = Poor 300-1050 = general 150-300 = Good 75-150 = Very good 0-75 = Great Package: 1 x GP2Y1010AU0F Compact Optical Dust Sensor Smoke Particle Sensor With Cable NEW