se/SE/stuff/P5_Automation-library-dev/ArduinoDeluxeKit/examples/p03_MomentaryButtonControlLED/p03_MomentaryButtonControlLED.ino

/*
  Demo code for Project 3 - Momentary Button Control LED
  
  Turns on and off a light emitting diode(LED) connected to digital  
  pin 9, when pressing a pushbutton attached to pin 2. 
  The momentary button will keep the state untill you push it again.
  
  by Maker Studio
  http://makerstudio.cc
*/

// constants won't change. They're used here to 
// set pin numbers:
const int buttonPin = 2;     // the number of the pushbutton pin
const int ledPin =  9;      // the number of the LED pin

// variables will change:
int buttonState = 0;         // 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(buttonPin, INPUT);     
}

void loop(){
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {     
    digitalWrite(ledPin, HIGH);  // turn LED on:    
  } 
  else {
    digitalWrite(ledPin, LOW); // turn LED off:
  }
}