SNS-GP2Y0A21YK0F

GP2Y0A21YK0F

GP2Y0A21YK0F is IR distance sensor 10-80cm with analog output. The output / distance relations is like this:

have nice article about measuring distance with Arduino

the final code is:

   int IRpin = 1;     // analog pin for reading the IR sensor
   
   void setup() {
     Serial.begin(9600);   // start the serial port
   }
   
   void loop() {
     float volts = analogRead(IRpin)*0.0048828125; // value from sensor * (5/1024)
     float distance = 65*pow(volts, -1.10);        // worked out from graph 65
     Serial.println(distance);                     // print the distance
     delay(100);                                   // arbitary wait time.
   }