int Led = 13 ;// define LED Interface int buttonpin = 3; // define D0 Sensor Interface int val = 0;// define numeric variables val void setup () { pinMode (Led, OUTPUT) ;// define LED as output interface pinMode (buttonpin, INPUT) ;// output interface D0 is defined sensor } void loop () { val = digitalRead(buttonpin);// digital interface will be assigned a value of pin 3 to read val if (val == HIGH) // When the sound detection module detects a signal, LED flashes { digitalWrite (Led, HIGH); } else { digitalWrite (Led, LOW); } }