brightness.js

var raspi = require('raspi-io');
var five = require('johnny-five');
var board = new five.Board({
	io: new raspi()
});

board.on('ready', function(){
	var virtual = new five.Board.Virtual(
		new five.Expander("PCF8591")
	);
	
	var a = new five.Sensor({
		// PCF8591 module YL-40
		// A0:LDR(Light Dependent Resistor)
		// A1:NC
		// A2 Thermistor
		// A3:Potentiometer
		pin:"A0",
		board:virtual
	});
	
  var ubidots = require('ubidots');
	
	var client = ubidots.createClient('<Your API Key>');

	client.auth(function () {
		this.getDatasources(function (err, data) {
			console.log(data.results);
		});
		// データ保存先のVariableを取得
		var v = this.getVariable('<Variable ID>')
		
		a.on("change", function(){
			v.saveValue(this.value); // Variableにデータを保存
			console.log(this.value);
		});
	});
});