int Led = 13 ;// define LED Interface int buttonpin = 3; // define the obstacle avoidance sensor interface int val ;// define numeric variables val void setup () { pinMode (Led, OUTPUT) ;// define LED as output interface pinMode (buttonpin, INPUT) ;// define the obstacle avoidance 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 obstacle avoidance sensor detects a signal, LED flashes { digitalWrite (Led, HIGH); } else { digitalWrite (Led, LOW); } }