RVM and Parallella: What a Difference a Shell Makes

RVM is an effective way to manage Ruby versions on Linux or OS X. RVM was working well on my Ubuntu-based Parallella, until one day it stopped:

linaro-nano:~> rvm list
rvm: Command not found.
linaro-nano:~>

rvm: Command not found. Fortunately, Zach Briggs and I were pairing at a joint OpenHack - ChicagoRuby event when the problem occurred. Zach is an ideal pairing partner; troubleshooting was smooth because he was there. Time to investigate.

Parallella Quick Start Guide (with gotchas)

Update: Here’s a 25-minute video intro to Parallella.

Parallella is a single-board supercomputer smaller than a deck of cards. While today’s fastest laptops contain four processor cores, Parallella has eighteen (2 ARM cores plus an Epiphany chip with 16 RISC cores). The maker of Parallella, Adapteva, is on a mission to democratize parallel computing. The company’s tag line is Supercomputing for Everyone.

Node.js Prep for OpenROV

OpenROV is an underwater robot controlled through a web browser. The server-side of the web app is written in Node.js, running on a BeagleBone Black inside the OpenROV.

You don’t need to know Node.js in order to pilot an OpenROV. And you don’t need to do anything in this article to construct an OpenROV from a kit. But if you’re the kind of maker who likes to dig deep into a project, you might enjoy exploring Node.js.

Get Back to Making Things

You know what the trouble is? We used to make things in this country, build things. Now we just put our hand in the next guy’s pocket.
~Frank Sobatka

David Lang is a maker. After a stint with a struggling Silicon Valley startup, David teamed up with former NASA engineer Eric Stackpole to build an underwater robot called OpenROV. That’s a two-sentence oversimplification of David’s maker journey, detailed in his book: Zero to Maker: Learn (Just Enough) to Make (Just About) Anything.

The book starts off like a novel, with the exploration of the mysterious Hall City Cave and an 1840s-era gold robbery. Fast-forward to the present day where a multi-disciplinary team of makers joins forces to create an inexpensive vehicle for underwater exploration.

The author was not a born maker. But through force of will, discipline, and the right mentorship, he grew from non-maker to co-founder of the OpenROV company in roughly one year.

Internet of Things at ACM

How many motors are in the typical automobile? The knee-jerk response might be “one, the big metal thing under the hood”. Upon further reflection, we may recall the motors that operate many devices in today’s automobile: windshield wipers, power windows, door locks, sun roof, reclining seats, and so on. Power devices were once luxury equipment. Today, since motors have fallen in price, most cars include these luxury items as standard equipment.

We take motors for granted, therefore motors have disappeared. And now, as it becomes possible to add a computer and an IP address to almost anything electronic, we bring about the Internet of Things (IoT). Computers are disappearing too.