Specialized Knowledge and the Courage to Execute

Teenagers are a tough audience. If you have ever spoken to a youth group, you know the challenge: Speak about something important without putting the youth to sleep. Tall order.

Three Stories

Boy Scout Troop 534 “Hey!” asked me to speak at the Troop’s annual reunion breakfast this year. I approached them with three stories centered around the theme of Specialized Knowledge and the Courage to Execute. What a boring title! But the three stories appealed to the group. Here’s a summary of the first story:

A tractor maker takes drastic action when when Enzo Ferrari (creator of the Ferrari sports car) pisses him off.

awesome_print_motion for RubyMotion

The Problem

Let’s say we’re building a version of Atari’s Pong in RubyMotion. We’re debugging an issue with the paddles; they don’t line up the way we want them to. Time to examine the playing field via the RubyMotion console.

pong-rm $ rake

Mouse over the playing field and Command-click to grab the entire playing field object in the RubyMotion console. Confirm that you grabbed the object by typing self at the console prompt.

(UIView(#9d820c0, [[0.0, 0.0], ...)> self

=> UIView(#9d820c0, [[0.0, 0.0], [480.0, 320.0]]), child of UIView(#c876920)

And then, to see what objects are on the playing field, use self.subviews to show the subviews array of the current object.

(UIView(#9d820c0, [[0.0, 0.0], ...)> self.subviews
=> [UIView(#9d82430, [[357.0, 175.0], [50.0, 50.0]]), child of
UIView(#9d820c0), PaddleView(#9d82580, [[410.0, 190.0], [20.0, 100.0]]),
child of UIView(#9d820c0), PaddleView(#9d82970, [[10.0, 190.0], [20.0,
100.0]]), child of UIView(#9d820c0), ScoreLabel(#9d82a80, [[110.0, 9.0],
[20.0, 42.0]], text: "1"), child of UIView(#9d820c0),
ScoreLabel(#9d83c90, [[350.0, 9.0], [20.0, 42.0]], text: "0"), child of
UIView(#9d820c0)]
(UIView(#9d820c0, [[0.0, 0.0], ...)>

This blob of text is difficult for the human brain to parse.

Solution: awesome_print_motion

Now, let’s try it with the awesome_print_motion gem.

Using RubyMotion to Build Something Useful

The Chicago RubyMotion User Group held its inaugural meeting this week. Thank you Dave Astels for organizing the group and for asking me to present. Thanks also to Dev Bootcamp for hosting the event.

Slides are embedded here:

OS X and RubyMotion, Finishing Up

There is something I neglected to cover in a previous blog post, Building an OS X App With RubyMotion. Once you’ve written the OS X app, where do you find the executable, and how do you add it to the Applications folder on the Mac?

Long-time Mac enthusiasts may already know how to do this. The information is included here for completeness.

Find, Drag, and Drop

First thing to note: A Mac app named [random-app].app is actually a directory, even though it appears to be a file when viewed in the Applications folder. If you’re curious, right-click on any app in the Applications folder and choose Show Package Contents from the speed menu.

A Portable Hack for Parallella

Beaglebone Black, Raspberry Pi, and Parallella are three small, powerful Linux-based computers. But in order to make these devices truly portable, we need a way to carry a monitor and keyboard along. This article describes one hack that works.

Inspiration in a Suitcase

The HP 5036 Microprocessor Lab gave me my first exposure to assembler language. I was eighteen, working my first software internship, and loving every minute of it. When I devised ways to complete my regular work faster than management expected, I had some time on my hands. So I spent time learning assembler with the HP 5036.