KY010 Broken Light Blocking Photo Interrupter Sensor Module For AVR PIC DIY KITS Photo interrupter module and a digital interface builtin 13 LED build a simple circuit to produce.photointerrupter warning lamp It comes with digital interfaces of the LED the light blocking access number 3 sensor interfaces sensing when the light interrupter Device senses a key signal LED lights otherwise off. Routines source code: int Led = 13 ;// define LED Interface int buttonpin = 3; // define the photo interrupter sensor interface int val ;// define numeric variables val void setup() { pinMode (Led OUTPUT) ;// define LED as output interface pinMode (buttonpin INPUT) ;// define the photo interrupter sensor output interface } void loop () { val = digitalRead (buttonpin) ;// digital interface will be assigned a value of 3 to read val if (val == HIGH) // When the light sensor detects a signal is interrupted LED flashes { digitalWrite (Led HIGH); } else { digitalWrite (Led LOW); } }