esp8266 memory problems

Here is the modified ds18b20 code. It uses a callback when the temperature is ready.

/* Copyright (c) 2013 Gordon Williams, Pur3 Ltd. See the file LICENSE for copying permission. */
/* Modified by HyGy */
/* Module for the DS18B20 temperature sensor */

var C = {
    CONVERT_T: 0x44,
    COPY: 0x48,
    READ: 0xBE,
    WRITE: 0x4E
};

function DS18B20(oneWire, device) {
    this.bus = oneWire;
    if (device === undefined) {
        this.sCode = this.bus.search()[0];
    } else {
        if (parseInt(device).toString() == device && device >= 0 && device <= 126) {
            this.sCode = this.bus.search()[device];
        } else {
            this.sCode = device;
        }
    }
    this.deviceTypeCode=parseInt(this.sCode[­0]+this.sCode[1]);
}

/** For internal use - read the scratchpad region */
DS18B20.prototype._readSpad = function(convert_t) {

    var spad = [];
    this.bus.reset();
    this.bus.select(this.sCode);
    convert_t=false;
    if (convert_t) {

        this.bus.write(C.CONVERT_T, true);
        this.bus.reset();
        this.bus.select(this.sCode);
    }
    this.bus.write(C.READ);
    for (var i = 0; i < 9; i++) {
        spad.push(this.bus.read());
    }
    return spad;
};

/** For internal use - write the scratchpad region */
DS18B20.prototype._writeSpad = function(th, tl, conf) {
    this.bus.reset();
    this.bus.select(this.sCode);
    this.bus.write(C.WRITE);
    this.bus.write(th);
    this.bus.write(tl);
    this.bus.write(conf);
    this.bus.reset();
    this.bus.select(this.sCode);
    this.bus.write(C.COPY);
    this.bus.reset();
};

/** Set the resolution in bits. From 8 to 12 bits */
DS18B20.prototype.setRes = function(res) {
    var spad = this._readSpad();
    res = [0x1F, 0x3F, 0x5F, 0x7F][E.clip(res, 9, 12) - 9];
    this._writeSpad(spad[2], spad[3], res);
};

/** Return the resolution in bits. From 8 to 12 bits */
DS18B20.prototype.getRes = function() {
    return [0x1F, 0x3F, 0x5F, 0x7F].indexOf(this._readSpad()[4]) + 9;
};

/** Return true if this device is present */
DS18B20.prototype.isPresent = function() {
    return this.bus.search().indexOf(this.sCode) !== -1;
};

/** Get a temperature reading, in degrees C */
DS18B20.prototype.getTempOld = function(verify) {

    var spad = null;
    var temp = null;
    if ((verify && !this.isPresent()) || !this.sCode) {
        return temp;
    }
    spad = this._readSpad(true);

    temp = spad[0] + (spad[1] << 8);
    if (temp > 32767) {
        temp -= 65536;
    }
    temp = temp / 16.0;
    return temp;
};

DS18B20.prototype.getTemp = function(callback) {

    var me=this;
    var temp=null;
    var spad=null;

  ow.reset();
  ow.select(this.sCode);
  ow.write(C.CONVERT_T, true);

  setTimeout(
    function() {
      var s = sensor._readSpad(false);
      var str="";
      s.forEach( function(v) { str+=" 0x"+v.toString(16); } );
      var temp = s[0] + (s[1]<<8);
      if (temp > 32767) temp -= 65536;

      switch (me.deviceTypeCode)
      {
        case 10:
           temp = temp/2.0;
            break;
        default:
          temp = temp/16;
          break;
      }
      callback(temp);
    },
    1000);
}

/** Return a list of all DS18B20 sensors with the alarms set */
DS18B20.prototype.searchAlarm = function() {
    return this.bus.search(0xEC);
};

/** Set alarm low and high values in degrees C - see DS18B20.prototype.searchAlarm.
  If the temperature goes below `lo` or above `hi` the alarm will be set. */
DS18B20.prototype.setAlarm = function(lo, hi) {
    lo--; // DS18B20 alarms if (temp<=lo || temp>hi), but we want (temp<lo || temp>hi)
    if (lo < 0) lo += 256;
    if (hi < 0) hi += 256;
    var spad = this._readSpad();
    this._writeSpad(hi, lo, spad[4]);
};

/** Initialise a DS18B20 device. Use either as:
  connect(new OneWire(pin)) - use the first found DS18B20 device
  connect(new OneWire(pin), N) - use the Nth DS18B20 device
  connect(new OneWire(pin), ID) - use the DS18B20 device with the given ID
 */
exports.connect = function(oneWire, device) {
    return new DS18B20(oneWire, device);
};