Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "There is no reason to recapitulate all the material covered in the START.htm presentation."

A block of code is set as follows:

function updateDuty() {
    // compute and adjust duty_cycle based on
    // desired position in range 0..1
    var duty_cycle = (position*0.115) + duty_min;
    b.analogWrite(SERVO, duty_cycle, 60, scheduleNextUpdate);
    console.log("Duty Cycle: " +
        parseFloat(duty_cycle*100).toFixed(1) + " %");   
}

Any command-line input or output is written as follows:

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install gdb

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "From your BBB's desktop, open up LXTerminal."

A few words about nomenclature

BBB: One thing that gets tiresome to repeat is the darned name of the board—BeagleBone Black. Too many syllables! So, instead of spelling it out every time, we will often just refer to the board as the BBB or the Black.

Desktop: Even though your BeagleBone Black has a desktop if you're running it on an external monitor or via an x11 (xwindows) session, we'll use the term desktop to refer to the client PC or Mac or Linux box that you're running as part of the development environment for the BBB.

Say hello to Major Tom

Ubiquitous and nearly inevitable in the world of computer programming is the typical beginner's example code "Hello World". Although we certainly use simple use cases to get you started, we don't use the Hello World rubric. Instead, because we're space geeks, we use "Major Tom" as a touchstone, evoking the astronaut from David Bowie's iconic Ziggy Stardust. To that end, we round out the book with an assortment of recipes using your BBB for tracking space stuff, satellites and the International Space Station, specifically. Geeks, indeed.