My Arduino based Cruise Control build indicator lights have been up and running for a couple of months now and so far so good.  It’s time to post the source code for the Arduino sketch and the Java app that runs on the machine that the build lights are connected to.

First, here’s a very short video of a successful build.  While a build is in progress, all 3 lights turn on, and at the end of the build, you get either solid red or solid green (hopefully), depending upon success!

The lights are connected via USB to a machine that sits nearby.  On that machine runs a Java program that attaches to the USB serial port and sends commands to the Arduino sketch to turn any of the 3 coloured lights on or off.  The sketch is very simple with no clever logic at all.  All it does is read the serial port and based on the value of 3 bytes, turns the lights on or off.  All the logic is contained in the Java program.

The Java program running on the attached PC connects to a Cruise Control server using the JMX protocol and waits for status updates for a given project.  These status updates occur when builds are started, and when they end.  There are also various informational properties that can be obtained from the build server, such as what time the last successful build was.  With this information, the lights can be set to show green for a good build less than 2 days old, amber for a build less than 4 days old but older than 2 days, and red for a build that’s older than 4 days (or a failed build).

I won’t go into a long post detailing the code now.  It’s a single Java source file with everything in (including the Arduino sketch in the comments), with a section for the command line handling, the JMX connection and the serial port code.  It uses the RXTX serial I/O library, so if you want to compile and run it, you’ll need to download that first.  I’m happy to answer any questions about the code, and of course, it’s free for you to do whatever you like with (WTFPL).  There’s not a lot of documentation specific to the Cruise Control JMX interface, but if you read through the actual Cruise Control source at sourceforge, you get a pretty good idea of all the properties available.   The methods to get the properties and the JMX events are fairly standard and the details from Sun here (PDF)  helped too.

CruiseControl/Arduino Lights Source Code

I’ve already done one post about software worth paying for, and I’ve got plenty of other software I want to mention lined up for the future.  However, you don’t necessarily have to pay for software, there’s an astonishing amount of freely available software that won’t cost you a penny.

You probably have data on your PC that you wouldn’t necessarily want other people to be able to see.  It might not be anything too serious, just a few passwords for web sites maybe. Alternatively, you might well have passwords for online banking written down somewhere, and these really should be looked after carefully.  Maybe you write documents for your job that are confidential or sensitive in nature, or you have personal diaries and journals that are private. Even though you might have to enter a password to log into your PC, that doesn’t mean other people can’t see you data.  On Windows PCs especially, unless you (or your IT department) have done some specific setup and are using special software, anything you put onto the hard drive (or store on a memory stick) is freely available for anyone to look at, if they can physically touch your machine, or indeed if they can dupe you into installing malacious software.

TrueCrypt is free software that solves this problem. It scrambles the data you save to a disc drive, or memory stick using cryptographic algorithms that mean only someone with the pass phrase (or a specially designated key file) can access that data. It will encrypt your hard drive so you need to enter a password before a machine boots if you like. You can also create ‘containers’ that can be accessed just like any other drive on your PC. The difference being that anything written to the TrueCrypt ‘virtual’ drive is securely encrypted. It’s very simple to use, and is available for Windows, Linux and Mac OS X, so transferring data between systems isn’t a worry.

The TrueCrypt web site is easy to understand and contains excellent documentation for a truely useful piece of software.  If you’ve got anything on your PC you want to look after carefully, TrueCrypt will almost certainly be what you’re looking for.

I started writing a post about TrueCrypt as the first in a series about “free software worth checking out” and I found myself going off on the current state of free and open source software.  Rather than bloat out the TrueCrypt post with this guff, I’ve given it it’s own post!

A couple of years ago, I don’t think I would have found myself saying this, but it truely is amazing, the quality of free software available today.  I’m currently writing this blog post on a PC running Ubuntu Linux 8.10 as it’s sole operating system. I’m using Firefox 3 and the blog software running on this website is WordPress.  All of these pieces of software, which have taken countless thousands of man hours to create, don’t cost anything except time to download, install or use, and that time cost is getting less and less it seems.

It wasn’t that long ago that free software took considerable dedication, time and expertise to use. I first started with Linux back in the early 90′s using Slackware, I dabbled again around 2005 with Gentoo.  From then on I’ve occasionally installed Red Hat, maybe SUSE or tried a live CD here and there and generally kept an eye out. Each time I spent any time with Linux though, I always came to the conclusion that anyone without a Computer Science degree wouldn’t stand a chance of getting anywhere with these systems.  I always got what I wanted out of them (an educational experience, a Mythtv PVR, NAS server, etc.), but then I’ve got a Comp/Sci degree and I live and breath computers.  The function was always there, but the barrier to entry was so high, only the few ever got to use it.

Ubuntu changed that for me recently though. I decided to overhaul my PC that had been running Kubuntu for a couple of years. I rarely touched it and it had been pretty much gathering dust.  I remember there were a lot of bugs when I first installed it, and I’d pretty much left it alone, using a Windows laptop for all my home computing needs. To my amazement, the Ubuntu install was painlessly easy.  Upon first boot up, the desktop looked great, it had working sound, needed no network configuration, updated itself automatically and accessed my NAS drive seemlessly.  Crikey, where was the catch?  Surely it wouldn’t be long before I was scouring forums, delving into the command line shell to edit config files and generally getting frustrated about a missing piece of function or funky bug, but that hasn’t happened yet!  Web browsing, email, IM, OpenOffice, Java, video encoding, music playback, video playback, if it didn’t already support such features out of the box, the simple package manager allowed me to add it without any hassles. I would give my wife and my mum  a PC running Ubuntu to use, it’s that easy.  I’m pleased that there really is a serious alternative to Windows these days.

Fun though these Java tutorials are, they can take some time to write. In order to try and stick to some sort of regular posting schedule I’m going to explore various areas of interest that I hope will produce more bite sized posts.

I use numerous pieces of software all day, every day, for a wide variety of computing tasks. Over the years, I’ve spent a lot of time learning to use different programs, researching alternatives when one is inadequate and using up 30 day trial periods. If I’ve found a program worth paying for, surely it’s a good idea to tell people about it. I’m certainly not the authority here, the idea is simply to talk a bit about software I like. If that spurs conversation and differences of opinion, that’s excellent.

XYplorer

XYplorer is a Windows file manager, it’s a replacement for Explorer.  It’s currently $24.99 for a lifetime license, which entitles you to free updates, which the author puts out very frequently. It has lots and lots of great features, is highly customizable, small, fast and makes working with files a breeze.

Use Windows Explorer for any length of time and you soon start to notice it’s shortcomings.  It’s annoying habit of forgetting you want to see a folder in detail view, a lack of bulk operation support,  no tabbed layout, limited history, no easy way to perform custom commands on files, locking up Windows for agonizing seconds or longer, I could go on… For many people (me included for a long time) it does enough not to warrant looking elsewhere. Eventually though, I needed something for the power user, and XYplorer was it.

I tried cheaper and free file managers, and trialled more expensive ones (some surprisingly expensive) but after using XYplorer,  I didn’t need to look anywhere else.  If you manage lots of files, have folders that stretch most of the way across a multi monitor setup, or are fed up with Windows Explorer, give it a go.

XYplorer