Line following robot using IR.Reflect.Array

bot.js

// Video: http://youtu.be/i6n4CwqQer0

var fs = require("fs"),
    five = require("johnny-five"),
    ReflectArray = require("./reflect.array"),
    board = new five.Board();

var stdin = process.stdin; 
stdin.setRawMode(true);
stdin.resume();

var calibrationFile = ".calibration";
var drivingRules = {
    0: {
      left: { dir: 'cw', speed: 0.01}, 
      right: { dir: 'ccw', speed: 0.07} 
    },

    1000: { 
      left: { dir: 'cw', speed: 0.02}, 
      right: { dir: 'ccw', speed: 0.05} 
    },

    2000: {
      left: { dir: 'cw', speed: 0.04}, 
      right: { dir: 'ccw', speed: 0.05} 
    },

    2500: {
      left: { dir: 'cw', speed: 0.05}, 
      right: { dir: 'ccw', speed: 0.05} 
    },

    3000: {
      left: { dir: 'cw', speed: 0.05}, 
      right: { dir: 'ccw', speed: 0.04} 
    },

    4000: {
      left: { dir: 'cw', speed: 0.05}, 
      right: { dir: 'ccw', speed: 0.02} 
    },

    5001: {
      left: { dir: 'cw', speed: 0.07}, 
      right: { dir: 'ccw', speed: 0.01} 
    }
  };

board.on("ready", function() {

  var eyes = new five.IR.Reflect.Array({
    emitter: 13,
    pins: ['A0', 'A1', 'A2', 'A3', 'A4', 'A5'],
    freq: 20
  });

  var wheels = {
    left: new five.Servo({ pin: 10, type: "continuous" }),
    right: new five.Servo({ pin: 9, type: "continuous" })
  };

  this.repl.inject({
    eyes: eyes,
    wheels: wheels
  });

  function init() {
    eyes.enable();
    wheels.left.stop();
    wheels.right.stop();

    calibrate(drive);
  }

  function calibrate(whenComplete) {
    var savedCalibration, calibrating = true;

    if(fs.existsSync(calibrationFile)) {
      eyes.loadCalibration(JSON.parse(fs.readFileSync(calibrationFile)))
      whenComplete();
      return;
    }

    console.log('Calibrating.  Press a key...');

    eyes.calibrateUntil(function() { return !calibrating; });

    stdin.once('keypress', function() { 
      calibrating = false; 
      console.log('Done:', eyes.calibration);
      fs.writeFile(calibrationFile, JSON.stringify(eyes.calibration));
      whenComplete();
    });
  }

  function drive() {
    eyes.on('line', function(err, line) {
      var rule;
      var threshold = Object.keys(drivingRules).find(function(r) { 
        return line <= parseInt(r); 
      });

      if(!threshold) {
        console.log("Could not find threshold for " + line);
      }

      rule = drivingRules[threshold];
      
      wheels.left[rule.left.dir](rule.left.speed);
      wheels.right[rule.right.dir](rule.right.speed);
    });
  }

  init();
  
});