Years of Lessons Learned from Home Automation

I’ve had three variations of my home automation setup. The first incarnation was a series of Linux command line utilities and cron jobs. There was some vague intention of a GUI, but that never really materialized. The second was a very enterprise-y J2EE implementation that involved Spring, MongoDB, layered architecture, and general wrangling with java. The current and most recent reboot involves nodes in a nod to Service Oriented Architecture and the “Internet of Things.” As I mentioned in my last post, the I’m turning a Raspberry Pi into a home automation controlling REST endpoint and then letting access and interaction happen in more distributed, ad-hoc fashion.

The flow of these applications seems to reflect the trajectory of my career from entry level developer to architect — from novice and hobbyist to experienced professional and, well, still hobbyist. And I think that, to an extent, they also reflect the times and trends in technology. It’s interesting to reflect on it.

When I started out as a programmer in the working world, I was doing a lot in the Linux world with C and C++. In that world, there was no cred to writing any kind of GUI — it was all about being close to the metal, and making things work behind the scenes. GUIs were for the faint of heart. I wrote drivers and kernel space code and automated various interactions between hardware and software. This mentality was carried over into the world of hobby when I discovered home automation. X10 was the province of hobbyist electrical engineers who wrote code out of necessity, and I fell in nicely with this approach. It was all about banging away, hacking, and making things work. Architecture, planning, testing, deployment strategies, etc… who cares? Making it work was all that mattered. I was a beginner.

As my career wound on, I started doing more and different kinds of programming. I found my way into web development with Java, did things in the .NET space, worked with databases, and started to become interested in architecture, software processes and honing my craft. With my newfound knowledge of a breadth of technologies and better software development approaches, I decided on a home automation reboot. I chose Linux and Java to keep the budget as shoe-string as possible. For a server, I could use the machine I took with me to college — a 400 MHz P2 processor and 384 meg of RAM. The hardware, OS, and software were thus all free, and all I had to do was pop for the X10 modules at $10-$20 a piece. Not too shabby.

I was cost conscious, and I had a technical vision for the architecture. I knew that if I created a web application on the server that what I did would be accessible from anywhere: Windows computers, Linux computers, even cell phones (which were a lot more limited as nodes in a network 5-6 years ago when I started laying this out). Java was a good choice because it gave me a framework to integrate all of the different functionality that I could imagine. And I imagined plenty of it.

There was no shortage of gold plating. Part of this was because I was interested in learning new technologies as long as I was doing hobby work and part of this was because I hadn’t yet learned the value of limiting myself to the minimum set of features needed to get going. I had advanced technically enough to see the value in architecture and having a plan for how I’d handle future added features, but I hadn’t advanced enough to keep the system flexible without putting more in up front than I needed. A web page with a link for turning a lamp on may not need data access, domain, service, and presentation layers. And, while I had grand plans to integrate things like home inventory management, recipe tracking, a family calendar and more, those never actually materialized due to how busy I tend to be. But I was practicing my craft and teaching myself these concepts by exploring them, so I don’t look back ruefully. Lesson learned.

Now, I’m rebooting. My old P2 machine is dying slowly but surely, and I recently purchased a lake house where I want to replicate my setup. I don’t have another ancient machine, and it’s time to get more repeatable anyway. A minimal REST endpoint on a Raspberry Pi is cheap and repeatable, and it lets me build the system in my house(s) more incrementally and flexibly. If I want to use WPF to build a desktop app for controlling the thing, then great. If I want to use PHP or Java on a server, then also great. ASP MVC, whatever. Anything that can speak REST will work, and everything speaks REST.

Maybe in another three years, I’ll do the fourth reboot and think of how silly I was “back then” in 2013. But for now, I’ll take the lessons that I’ve learned in my reboots and reflect. I’ve learned that software is about solving problems for people, not just for the sake of solving the problem. A cron job that I can tweak turns my lights on and off, but it doesn’t present any way that the system isn’t weird and confusing for my non-technical girlfriend. I’ve learned that building more than what you need right now is a guarantee that you’ll have more complexity than you need and less benefit. I’ve learned that a system composed of isolated, modular components is better than a monolithic juggernaut that can handle everything. And, most importantly, I’ve learned that you’ve never really got it all figured out; whatever grand plan you have right now is going to need constant care and refinement.

  • http://www.jwagner.org/ Jay

    This is a great post. I’ve only recently begun to scratch the surface of home automation, been thinking of a weird scheme involving my turtle tanks, but I’m definitely in the beginner-hobbyist phase, and had no idea where to start or stop. As for “never really figuring it all out” – sage words indeed. Thanks for writing this!

  • http://www.daedtech.com/blog Erik Dietrich

    Glad if you enjoyed. Feel free to stop back and let me know what progress you make with your own setup — I’m always interested in ideas.

  • http://www.daedtech.com/blog Erik Dietrich

    I think that the idea of a series of small components tends to give the kind of flexibility to which I was referring in that. The small size lets you avoid gold plating and the loose coupling lets you adapt easily to change. Of course, there may be better ways to get there. This is just the best one that I happen to have found so far.