const int irsensor = 2; // the number of the pushbutton pin const int ledPin = 13; // the number of the LED pin // variables will change: int irstate = 1; // variable for reading the pushbutton status void setup() { // initialize the LED pin as an output: pinMode(ledPin, OUTPUT); // initialize the pushbutton pin as an input: pinMode(irsensor, INPUT); } void loop() { // read the state of the pushbutton value: irstate = digitalRead(irsensor); // check if the pushbutton is pressed. If it is, the irstate is HIGH: if (irstate == LOW) { // turn LED on: digitalWrite(ledPin, HIGH); } else { // turn LED off: digitalWrite(ledPin, LOW); } }