Rant: Why I love what the Chromecast stands for

I’ve had my hands on this Chromecast for almost a week now and I love it. Years ago I hacked my first Xbox after seeing [Kevin Rose] do it on The Screensavers (I did the hardware mod but that’s inconsequential). Why did I do this? So that I could run Xbox Media Center, the predecessor of XBMC. Since then I’ve dreamed of a device which can be hung on the back of the TV with Velcro and run XBMC. We basically got there with the Raspberry Pi, but the Chromecast is the form-factor that I had always envisioned. This lets me watch Netflix, while the RPi runs XBMC. The two are match made in heaven for under a hundred bucks.

That’s why I love the Chromecast device itself, but the bigger picture is that I love what it stands for. Keep reading to see what i mean.

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Visualize Twitter with an LED matrix

visualizing-twitter

What’s your favorite color? Don’t tell us, Tweet it to [Sebastian’s] favorite color Twitter display and you’ll be contributing to the artwork hanging on his wall.

This answers a very important question, what do you do with your projects after they’re completed? For us the best part is the planning and building. Once it’s done the thrill is pretty much gone for us. We haven’t even switched on our Ping Pong clock in over a year. But [Sebastian] recently dusted his 10×10 LED matrix for this project.

Tweets are parsed by a Python project he wrote to try out the Twitter API. It looks for a set list of colors . He asserts that people aren’t that creative when you solicit their favorite color but to prove him wrong we’re going to say our favorite is Amaranth. After it finds the color it pushes it to the next pixel in the spiraling pattern shown above. But wait, there’s more! To give the pixels a but if extra meaning he uses the total length of the tweet to set intensity.

If you need a Titter enabled hack that displays a bit more specific data you’ll want something that can actually display what was Tweeted.

Minecraft for RPi Released

Minecraft for RPi

Mojang, the folks behind Minecraft, have officially released Minecraft: Pi Edition. This free version of the popular game is optimized to run on the Raspberry Pi hardware, and has an API that exposes the game’s internals to a variety of programming languages.

Mojang intends this release to be an educational tool for teaching and learning programming. Since the API provides instant feedback in the game, it could be an interesting way to make learning to code fun for people of all ages.

Having access to the API on a RPi also means that the game can be connected to the real world. For example, using Python and the RPi.GPIO, pins on the GPIO header can be used for output or input. This creates a slew of possible hacks that interface with the game.

Any ideas on what you’d like to do with Minecraft on a RPi? Let us know in the comments. Also, we coincidentally just printed a minecraft pick on our 3d printer. There’s a time lapse video of it after the break!

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Rack Mount Home Automation with a RPi

RPi Home Automation

[Patrick] wanted to have centralized sensing and control over various parts of his house. His Raspberry Pi Home Automation System integrates a bunch of functionality in one rack mount package, salvaged from an old network switch.

The automation system is based on a Raspberry Pi running Arch Linux, which talks to an ATmega over SPI. We’ve seen this setup used many times before to add additional ports to the Raspberry Pi, but what makes [Patrick]’s build unique is the amount of control he’s built into the system.

The box controls outdoor lighting at sunset and sunrise, generates wakeup calls, controls IR cameras, and plays sounds based on events. It’s capable of monitoring sump pump water level, the state of a house alarm, and more. A custom REST API is used to interact with the device. This allows for programs on any platform to interface with his home, and acts as an API for his house.

[Patrick] provides a lot of details in his build log, which should be helpful to anyone looking to roll their own home automation system. The source is also provided.

Using an oscilloscope as a composite video adapter

Confronted with a monitor that would display neither HDMI signal, nor composite video, [Joonas Pihlajamaa] took on a rather unorthodox task of getting his oscilloscope to work as a composite video adapter. He’s using a PicoScope 2204 but any hardware that connects to a computer and has a C API should work. The trick is in how his code uses the API to interpret the signal.

The first thing to do is make sure the voltage levels used in the composite signal are within the tolerances of your scope. [Joonas] used his multimeter to measure the center pole of the RCA connector and found that the Raspberry Pi board puts out from 200 mV to 2V, well within the PicoScope’s specs. Next he started to analyze the signal. The horizontal sync is easy to find, and he ignored the color information — opting for a monochrome output to ease the coding process. The next big piece of the puzzle is to ascertain the vertical sync so that he knows where each frame starts. He got it working and made one last improvement to handle interlacing.

The proof of concept video after the break shows off the he did. It’s a bit fuzzy but that’s how composite video looks normally.

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Forget Siri – make Wolfram Alpha your personal assistant

So you can spend a bundle on a new phone and it comes with a voice-activated digital assistant. But let’s be honest, it’s much more satisfying if you coded up this feature yourself. Here’s a guide on doing just that by combining an Asterisk server with the Wolfram Alpha API.

Asterisk is a package we are already familiar with. It’s an open source Private Branch Exchange suite that lets you build your own telephone network. Chances are, you’re not going to build one just for this project, but if you do make sure to document the process and let us know about it. With the Asterisk server in place you just need to give the assistant script an extension (in this case it’s 4747).

But then there’s the problem of translating your speech into text which can be submitted as a Wolfram query. There’s an API for that too which uses Google to do that translation. From there you can tweak abbreviations and other parameters, but all-in-all your new assistant is ready to go. Call it up and ask what to do when you have a flat tire (yeah, that commercial drives us crazy too).

[Thanks M]

SMS gateway lets you Twitter by text message

[GuySoft] threw together a cellphone-based SMS gateway that allows him to push text messages to Twitter. Once up and running, it can be used by multiple people, either with shared or individual Twitter accounts. At its core, this setup uses the cellphone as a tethered modem on a Linux box. The open source software package, Gammu SMSD, provides hardware hooks for phones running in modem mode. The package is already in the Ubuntu repositories but it runs cross-platform and can be downloaded from the project site. This gave [GuySoft] the ability to script a framework that checks for received SMS messages, compares the incoming phone number for a match on a saved list, then pushes the message from a confirmed number to Twitter via their API.

A web interface is used to register new numbers and associate them with Twitter accounts. On the back-end, [GuySoft’s] own Python script handles the translation of the message. You can download all of the code, and get more insight on setup from the readme file, over at the GitHub repository.