Occasional Comment

One of the philosophical principals underlying Ruby on Rails is that software should be opinionated. I have been thinking about what that means a lot lately and have decided that being opinionated is a good trait in general. I have decided that I will be opinionated and share my opinions with anyone who will listen. In particular, I will share my opinions here.

I have concluded that software engineering is at best a misnomer and at worst a detriment to the development of quality software. Engineering is a philosophy of creating physical artifacts that has been developed empirically for the last two or three centuries. Software is not a physical artifact.

When I have a physical artifact and I give it to you I no longer have the artifact. When I have a piece of software and I give it to you, I still have it. Your having it doesn’t reduce the utility of my having it. When I design a physical artifact, I want to get all the details right before I build it because materials are expensive. When I design software, the easiest way to figure out the details is to create a prototype and then iteratively improve it until it is right.

The point being that building multiple versions doesn’t incur large material costs. These are only two of many reasons that software development is very different from the process we know as engineering. Calling Software Development Software Engineering raises inappropriate expectation in those that don’t understand Software Development.

I’ll rant on this topic more later but I’m going to call it a night right now.

This morning I was thinking about a project that I am doing in Ruby. I found myself thinking to myself  “I sure am looking forward to getting more intimately familiar with active-record.” Active-record is the Object-Relational-Mapping component of Ruby on Rails.

I love a package that makes you eager to learn more about it. Not to say that you have to be intimately familiar with active-record in order to use it. Rails is just so well thought out that studying the API is actually fun. And, Rdoc, the Ruby documentation package, makes writing extensive documentation of your code so easy that programmers usually do a pretty good job of documenting their code.

I have been using active-record in my Rails apps for several years now. The reason that I needed to delve deeper into active-record at this point is that I am getting data from an external source (I’m scraping it from a web page), parsing it using nokogiri, another fine Ruby package, and then caching it in a local database. Consequently, I am having to do some thinking about how to structure the data that I cache.

Let’s face it, I’m not really all that experienced at database architecture. I can hack a little SQL when I need to but I haven’t had to do a lot of data normalization since I studied databases in college. Rails makes it easy to play around with your schema until you get it just right. I don’t mean to gush or anything but Rails makes these things so easy that it feels like playing instead of work. In my case, I guess it is playing, at least to the extent that I am not being paid to do it. But that’s another story.

It all started innocently enough. I had $50 worth of Amazon gift certificates so I bought an Arduino Duemilanove from Hacktronics with part of the money. It came and I was thrilled to start blinking LEDs with it right out of the box. I wrote a little program that flashed “SOS” in Morse code. My wife said, “That’s kind of depressing.” So I changed it so that it sent “LOVE” in Morse code instead.

I don’t know why I am so surprised when things work the way they are supposed to. I think it probably goes back to all the times I built electronics kits and had to troubleshoot them for days to get them to work (if they ever worked at all). In any case, the bug had bit me. I started scouring the Internet for Arduino based projects.

One of the reasons that I was drawn to the Arduino in the first place was the concept of shields. Understand that this was not a new concept to me. The robots at work had been expanded through the addition of daughter cards that plugged into the motherboard. But the Arduino had dozens of shields that interfaced to all kinds of interesting hardware. And the best thing of all was that they were affordable on my next to non-existent budget.

I decided that I was going to build a robot from scratch. I had built a BOEbot and I still love to tinker with it but I had the urge to create a unique robot that was my design from the ground up. Oh, alright. I intended to assemble it from parts but I intended to build many of the boards as kits and assemble all the various pieces to make a unique final product. And what is really exciting is that it wasn’t just possible, it was down right easy.

I decided to build my robot around a chassis consisting of a Clementine tangerine crate that I had saved. I decided to use Google SketchUp to build a scale 3D drawing of the crate so that I could better visualize how I planned to transform it into a robotic vehicle. I managed to draw the crate itself fairly quickly but I’m still working on drawing the rest of the parts of the robot.

I drew up a prioritized list of parts that I thought I would need for the robot. At the top of the list was a Proto Shield. A Proto Shield is a board that has many uses but is often used as a place to mount a mini breadboard for experimenting with various hardware interfaces. The other major item on the list was a Motor Shield. The Motor Shield that I bought has connectors for 2 PWM servos and can control up to 4 bi-directional DC motors.

While I waited for my new hardware to come in, I decided to play with the hardware that I already had. I took one of the Infra-red receivers that came with my BOEbot and an old Sony CD player remote that I found laying around (the CD player had gone to hardware heaven years ago) and decided to see if I could get them to work together using the Arduino as the controller for the IR receiver. I got the circuit hooked up pretty quickly. Note: when building a circuit on a breadboard of one battery operated robot for control by another battery operated device, make sure you use a common ground. I eventually decided to just use the USB power from the Arduino.

Now I was ready for software. I Googled Arduino and IR and found RTFA‘s video on YouTube. I followed the link to his site and downloaded his code as a starting point. I hacked it to work with the particular remote that I was using and before my Proto Shield had even arrived I had created my first Arduino based hardware hack.

Then the hardware arrived. As I was soldering the power plug on the end of the wires coming out of the  9 volt battery holder with switch that I had bought, I decided that I was going to need a better soldering iron than the little pencil style iron that I had used for 30+ years.

The two criteria that I had were that it had to have a switch so that I didn’t have to bend over to plug it in and unplug it every time I used it and it had to have a shielded stand so that I could safely set it down while it was hot. The next day, I want to my friendly neighborhood Radio Shack and decided that the difference in price between the iron that met my minimal requirements and one that was variable digitally temperature controlled was small enough that I couldn’t justify not buying the fancy one.

It took me two evenings working about an hour an evening to assemble and test the Proto Shield. It took about 5 minutes to move the IR receiver circuit over to the Proto Shield and get it working.

Stay tuned. More mania is on the way.

I recently read a book called Getting Real by the folks from 37signals, creators of Ruby on Rails, Ta-da List, Writeboard, Backpack, and Basecamp among other Ajaxian web application goodness. While superficially a book about how to start a successful business selling services based on web applications, a topic they have plenty of credibility with, the advice in this book is applicable to a much broader realm of endeavors.

I was so inspired by it that I have dusted off several projects that were laying dormant and started actively doing them again. Of course this is also aided by the insights that I have been gleaning from the Getting Things Done book. I have also bought a Backpack Basic account so that I can use their wonderful calendar. Enough raving for now. Got to get some things done .

I’ve downloaded and installed Firefox 2.0 on my iMac at home and my Windows XP laptop at work. I have to say, I’m impressed. At first when Firefox told me that Tab Mix Plus wasn’t compatible with 2.0, I was upset. They are promising a 2.0 compatible version real soon now.

Then I discovered that most of its functionality had been incorporated into the core implementation. The only feature that I miss is the ability to click on a tab and duplicate it. When I looked in the add-on directory, I discovered an extension called Duplicate Tab that does what I want. I downloaded and installed it and when I told the installer to restart Firefox I was pleased and surprised when Firefox came up with the same tabs loaded. Nice feature.

I don’t know if its just me but the rendering of photographs, in particular scaled jpegs, seems crisper. I haven’t delved into the release notes to verify that though. It may just be the shiny new default buttons and the crisp new tab implementation make me think that the page itself is crisper. In any case, I like it a lot.