Routines source code: int Led = 13 ;// define LED Interface int buttonpin = 3; // define the digital temperature sensor interface int val ;// define numeric variables val void setup() { pinMode(Led, OUTPUT) ;// define LED as output interface pinMode(buttonpin, INPUT) ;// define digital temperature sensor as output interface } void loop () { val = digitalRead(buttonpin) ;// digital interface will be assigned a value of 3 to read val if(val == HIGH) // when the digital temperature sensor detects a signal, LED flashes { digitalWrite(Led, HIGH); } else { digitalWrite(Led, LOW); } }