Archive for June 2007
The other night I posted about TrafficStop to the forums over at HackedGadgets. Alan was kind enough to throw me up on the front page for June 27. Honestly, I was pretty stoked about that. It may sound odd to those of you that have already achieved internet notoriety, but it was something akin to losing my internet virginity.
If that had me feeling pretty good, then imagine my surprise when I was reading my daily RSS feeds and read about my project on engadget! The project even got dugg, although the last time I checked it only had three diggs, I still feel that’s quite an accomplishment when you consider the fact that I have almost no experience in the hardware hacking arena.
I just wish that I’d have had the forethought to configure some stat gathering tools for my site, so I could get an accurate count of how many visitors I’ve had in the last 48 hours.
That’s enough ego stroking for one day. I think it’s time to post some “lessons learned” from this whole ordeal.
I’ve been working with a Weller WP30 soldering iron for a while. It’s a great iron but the included tip is a little big for my tastes. I was watching the video for DiggTheDiggButton last night and I noticed that Limor from adafruit uses a very fine tip. I had no idea what tip I would need, but I was lucky enough to stumble across the image below from Action Electronics. So I ordered myself a couple of ST7 tips tonight tonight replace that cumbersome ST3 that came with the iron.
I wound up spending a ridiculous amount of time just getting the Delcom driver to work on OS X. The program was written years ago by an Apple developer, and a lot has changed since then. There were a few minor problems that caused me a great deal of headache.
For instance, there were a few lines of code that checked for null values using the tried and true:
if(something != null)
doSomething();
GCC kept complaining that I was using an object in a mathematical operation. I wasn’t having much luck finding anyone else on the internet who seemed to have the same problem. Once again, Tom came to my rescue when he commented that he always used the form:
if(!something)
doSomething();
I think I wasted roughly two evenings just getting the Delcom drivers to compile, and that wasn’t the last time that Tom would ride to my rescue.
Even though the project was born out of a need at work, I decided that I would target the Mac platform first. There’s no good reason for this decision, other than the fact that I love Macs.
My original design idea was actually to calculate the number of windows open on the system at any given time, and change the light based on that figure. There’s actually a major distinction between how many windows you have open, and how many applications you have running. I was violently opposed to polling the system for status changes. I demanded that the light changed instantaneously when a new event occured.
My friend Tom recommended that I check out the NSDistributedNotificationCenter feature in Cocoa. This is a class that is available to all applications, and allows you to get some pretty interesting information from your computer such as when a new application is launched or the computer is preparing for sleep. Unfortunately, it doesn’t allow you to find out how many windows are open on the system.
Tom also gave me some applescript code that would enable me to count the number of open windows on the system, but I insisted on using notifications. I was certain that other programs, such as Mail.app and iCal would post useful notifications that I could use to determine the number of unread emails, scheduled appointments etc
I set out in search of a novelty stoplight again. By now I was certain that I could complete the project, and it was time to get the rest of the hardware on order. I selected a generic looking Random Flashing Traffic Light from www.blacklight.com despite never having heard of the company.
It was time to focus on the software.
