problem with DS18B20

I am using rev. 1.3b that arrived on friday and my env is:

{"VERSION":"1v46","BUILD_DATE":"Jan 24 2014","BUILD_TIME":"17:28:16","BOARD":"ESPRUINOBOARD","CHIP":"STM32F103RCT6","CHIP_FAMILY":"STM32F1","FLASH":262144,"RAM":49152}

// ds18b20
// sig white
// 3v3 red
// gnd black
// 3530822130496018984

clearInterval();

LED1.reset();
LED2.reset();
LED3.reset();

var  l = false;
setInterval(function() {
  l = !l;
  LED1.write(l);
}, 1000);

setWatch(function() {
  LED2.set();
  clearInterval(id);
  setTimeout(function() {
    LED2.reset();
  },2000);
}, BTN1, {repeat:true, edge:'rising'});

setBusyIndicator(LED3);

var ow = new OneWire(A0);
var sensor = require("DS18B20").connect(ow);
id = setInterval(function() {
  console.log(sensor.getTemp());
}, 1000);

and that is my code