NewBee - unknown "possible" memory leak?

Being a hard core Arduino user, I decided to switch to the Espruino.
I put together a DS18B20 data logger. After a few days, I noticed
on the I2C LCD, that memory usage was increasing from 646 to 651.
Any help is appreciated to track down this memory leak. (See code below)

BTW ... I am very impressed with the amount of program code needed for this project. It would of taken thousands of lines of code for the Arduino.

/*
DS18B20 Data Logger
Rev. 1.0b
6/26/14
Espruino: v 1.3: firmware: v 65 WEB-IDE: v 45
Windows 8.1 / Chrome
Hardware: I2C 4x20 LCD, DS18B20, I2C RTC DS3231
Bugs: Memory usage 646 but after a few days increases to 651 ???

Program description:
Uses 1-wire DS18B20 for the temperature sensor.
The DS18B20 temperature is logged along with time/date to SD and LCD.
1-wire and 1 I2C bus is used.

Program credits:
SD data logger code snippet was used from an unknown Espruino forum member.

Note: 3.3k pull-ups for I2C LCD/RTC.
*/

function onInit(){
var ow = new OneWire(A1);
var sensor = require("DS18B20").connect(ow);
sensor.setRes(12); 
digitalWrite([LED1,LED2,LED3],0b100);
var lcd = require("HD44780").connectI2C(I2C1);
I2C1.setup({scl:B8,sda:B9});
lcd.clear(); 
setTimeout("digitalWrite([LED1,LED2,LED3­],0b010);", 1000);
setTimeout("digitalWrite([LED1,LED2,LED3­],0b001);", 2000);
setTimeout("digitalWrite([LED1,LED2,LED3­],0);", 3000);
// Delay start-up for diagnostics (above) and for LCD clear
I2C1.setup({scl:B8, sda:B9});
var rtc = require("DS3231").connect(I2C1);
}

var fs = require('fs');
var testName    = "TEST152L.LOG";
var testDetails = "Data Logging DS18B20 to SD";
var logInterval = 5000;
var logEntry    = 0;

var ow = new OneWire(A1);
var sensor = require("DS18B20").connect(ow);

I2C1.setup({scl:B8,sda:B9});
var rtc = require("DS3231").connect(I2C1);

/* Set Dow Time/date - comment out lines out below after first use!
Usage:
rtc.setDow("day of the week") Monday,Tuesday ...
rtc.setDate(date,month,year);1-31,1-12,0­-99
rtc.setTime(hours,minutes); Military Time 
Set time exactly on minute roll-over (+ 1  min)
*/

//rtc.setDow("Thursday");
//rtc.setDate(26,6,14);
//rtc.setTime(19,25); 

I2C1.setup({scl:B8, sda:B9});
var lcd = require("HD44780").connectI2C(I2C1);
lcd.clear();


// Initialise log file here with header information
console.log(testDetails);
fs.appendFileSync(testName, testDetails);

// Function to log some data every so often
setInterval(function(){
    // Indicate each time function is executed 
    digitalPulse(LED1, 1, 100);
// Log some data.
    logEntry++;
 var logString = logEntry + " " + (sensor.getTemp(true)* 1.8 + 32 + " F. ") +
    (rtc.readDateTime()) + " "  + "\r\n";

    //console.log(logString); <---- do not leave in without USB (will halt)
    //console.log(process.memory().usage); <--- do not leave in without USB (will halt)
    fs.appendFileSync(testName, logString);
    lcd.setCursor(0,0);
    lcd.print("DS18B20 Logging ..."); 
    lcd.setCursor(0,1);
    // lcd needs a string ????
    lcd.print("TempF: " + new String(sensor.getTemp(true)*1.8 + 32));
    lcd.setCursor(0,2);
    lcd.print(rtc.readDateTime());
    lcd.setCursor(0,3);
    lcd.print(new String(process.memory().usage));
    
}, logInterval);