Mark Villacampa

Servos are small motors that can rotate 180 degrees and whose position can be controlled. Some types of Servos can also rotate continuously. However, normal servos can be hacked to rotate 360 degrees. They are built with a small DC motor, a potentiometer and some control circuitry. The rotation of the motor changes the position of the potentiometer which acts as feedback for the control board to know the exact position of the servo. This behavior is very useful for some applications, but not so much for others where we don’t care about the current position of the servo but want to perform full rotations (like rotating the wheels of a robot). In this tutorial we’re going to hack a[…]

TL;DR; Add this lines to a file named debugger_cmds in the root of your RubyMotion app. Then run your app with rake debug=1 to have Reveal automatically loaded.

Remember to add debugger_cmds to your gitignore file. Long version Reveal is an awesome tool to debug and modify iOS views during development. However you usually have to modify your Rakefile to load it, and it might not please your coworkers if you accidentally commit the changes. Reveal connects to your app by loading a library, starting a Bonjour server and streaming data both ways. To include Reveal’s framework in your project you would usually do it in your Rakefile. In order to avoid having to modify your project to load[…]

Lately, I’ve been interested in programming language implementations in general, and LLVM in particular. You’ve probably heard of many projects based on LLVM like emscripten, rubinius, clang, rust or Rubymotion. Since I learn better by example, I wanted to have a large LLVM-based programming language codebase to experiment and tinker with. Given I’m already familiar with part of its codebase, Macruby seemed like the best option. Macruby is the predecessor of Rubymotion, and if you’re looking to build iOS or OSX apps, the latter is the best option for you. However if you want to learn more about LLVM and programming language implementations like me, the Macruby source code is perfect. As I explain how to get your hands on[…]

The past CES show in Las vegas included a lot of 3D printing, and some of the industry leaders introduced new 3D printers. Some of these new models came with news regarding material cartridges. 3D Systems has always used proprietary filament cartridges with an incorporated chip very much like traditional ink printers. Makerbot is heading towards that direction with its new printers. While not coming so far as to include a chip , the new Replicators feature special compartments where the spool is held in place, making it more difficult for third party spools to fit in. Although proprietary cartridges make it easier to hide the filament from sight and make for more externally appealing printers, I would not be[…]

Danger was a company founded in 2000 by Andy Rubin, Matt Hershenson and Joe Britt, former employees of Apple, General Magic, Catapult Entertainment and WebTV among others. Not many people know abut Danger in Europe, since they were mostly known as the creators of the T-Mobile Sidekick, a very popular early smartphone. The company was bought by Microsoft in 2008 and continued manufacturing devices for T-Mobile and other carriers until 2010. Inside Microsoft, the ex-Danger team was responsible for the development of the Kin, Microsoft’s smartphone fiasco. In a rare interview with Danger co-founders from early 2004, Andy Rubin explains with all detail Danger’s business model, which is almost exactly the same business model Google’s Android or Amazon’s Kindle have[…]

Lately, I’ve been reading a lot about the history of the Internet and Dot-com bubble startups. Very much like a music student would learn about the life and achievements of his favorite musicians and study what made them great, learning from past successes and failures of entrepreneurs feeds my startup analyst side. These days I’m reading The Everyting Store, a great book by Brad Stone about the history of Amazon.com. Interestingly, the company founded by Jeff Bezos launched at the same time Netscape went public: {% blockquote %} On August 9, 1995, Netscape Communications, the corporate descendant of the pioneering Mosaic Web browser, went public. On the first day, its stock jumped from an initial price of $28 per share[…]

CES has become the conference of choice for the two biggest personal 3D printer manufacturers to show their latest developments. I’m talking about Stratasys-owned Makerbot and 3D Systems. Makerbot Replicator Makerbot presented 3 new models in the Replicator line, notably dropping the model numbering ala Apple with its iPad. The current lineup is referred to as 5th generation Makerbots. The Replicator Mini, with a price tag of $1375, comes to compete with the Cube from 3D systems and other preassembled 3D printers from less known manufacturers like Afinia or Solidoodle. The Replicator is the natural successor of the Replicator 2, and its 700$ price tag increase with respect to its predecesor better positions it as a professional machine (or “prosumer”[…]

Like any good geek, I have a Raspberry Pi. A few months ago, its SD card slot broke and the SD card couldn’t be held in place, leaving my Raspberry Pi useless (since the operating system lives inside said SD card). This isn’t something new to Raspberry Pi owners. I looked for a replacement part, and ordered one on Ebay (from UK, of course). Here’s a good tutorial on how to desolder your old SD slot and solder the new one. But being pragmatic as I am, I decided to tackle the disease, and not only palliate the symptoms. The SD card slot on the Raspberry PI isn’t ideal. It leaves most of the SD card outside of the PCB,[…]

There are several ways to configure shortcuts in OSX. In app shortcuts Some apps have internal preferences to set certain shortcuts. Some of this shortcuts will only work in the context of the app, some others will be global shortcuts Application Shortcuts in the System Preferences In System Preferences > Kayboard > Keyboard Shortcuts > Application Shortcuts we can assign shortcuts to the actions of an app upper menu bar and the context menu (right-click menu). It is as simple as knowing the exact label of the menu button, and assigning a shortcut to it. I usually use this to assign “⌥⌘→” and “⌥⌘←” to the “next tab” and “previous tab” buttons, to navigate apps that implement something similar to[…]

I have just done a fresh install of Mountain Lion, and installed all my development tools one by one. I have carefully selected the ones I really use, and installed nothing else but those. Here’s a list:*Dash: API Documentation browser. I use it mainly for Cocoa documentation, but it has compatible docsets for almost everything you can imagine. However I prefer the website version for some documentation like Ruby’s or Rails’ documentation. Alfred: Very useful to launch apps. I have also set search shortcuts for some websites and I run some bash scripts directly from there. Codekit: If you use a preprocessor like SASS, LESS. etc, this app watches for changes in your project directory, processes your files and auto[…]