We're going to learn how to connect a strip of LED lights to a computer and control them with your programs. This approach controls the lights with Javacript, but there are librariese for pretty much every programming language.

Using Johnny Five

Install johnny-five with the following command: npm install johnny-five

Installing Firmata firmware on arduino

Open Arduino editor, then navigate to File > Examples > Firmata > StandardFirmataPlus

Upload it to your arduino

Running first Johnny Program

For our first test, let's do something really simple. Connect an LED to the ground and a digital in port on your Arduino:

Now create a new Javascript file with the following code (source):

var five = require("johnny-five"),
    board = new five.Board();

board.on("ready", function() {
  // Create an Led on pin 13
  var led = new five.Led(13);

  // Strobe the pin on/off, defaults to 100ms phases
  led.strobe();
});

Replace the 13 from five.Led(13) with the number of the digital pin you plugged the LED into.

Run the code, and voila - your LED should be blinking!