text: var five = require("../lib/johnny-five.js");
  var board = new five.Board();
  
  board.on("ready", function() {
    var virtual = new five.Board.Virtual(
      new five.Expander("PCF8591")
    );
  
    var a = new five.Sensor({
      pin: "A0",
      board: virtual
    });
  
    a.on("change", function() {
      console.log(this.value);
    });
  });
  