Thumbs-Down Songs On Pandora With Your Mind

February 7, 2014 by Kristina Panos 12 Comments

[Steven] likes music. Like many of us, he uses Pandora to enjoy the familiar and to discover new music. Now, Pandora means well, but she gets it wrong sometimes. [Steven] has had a Mindwave Mobile EEG headset lying around for a while and decided to put it to good use. With the aid of a Raspberry Pi and a bluetooth module, he built a brainwave-controlled Pandora track advancing system.

The idea is to recognize that you dislike a song based on your brainwaves. The Mindwave gives data for many different brainwaves as well as approximating your attention and meditation levels. Since [Steven] isn’t well-versed in brainwavery, he used Bayesian estimation to generate two multivariate Gaussian models. One represents good music, and the other represents bad music. The resulting algorithm is about 70% accurate, so [Steven]’s Python script waits for four “bad music” estimations in a row before advancing the track.

[Steven] streams Pandora through pianobar and has a modified version of the control-pianobar script in his GitHub repo. His script will also alert you if the headset isn’t getting good skin contact, a variable that the Mindwave reports on a scale of 0 to 200.

Stick around for a demo of [Steven] controlling Pandora with his mind. If you don’t have an EEG headset, you can still control Pandora with a Pi, pianobar, and some nice clicky buttons.

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Pi-Powered Radio Over IP

February 6, 2014 by Brian Benchoff 12 Comments

[KP4TR] connected a Raspberry Pi to a small, cheap handheld radio, allowing anyone within a few miles of his house to connect to amateur radio operators all around the world.

For the hardware, [KP4TR] is using a Raspi, a Baofeng BF-888s 400MHz – 470MHz walkie-talkie radio, a USB sound card, and a pair of transformers for the 5V and 3.7V lines. All this is tucked away in a remakably vintage-looking plate and standoff enclosure, complete with acorn nuts and an RGB LED connected to the Raspi’s GPIO to indicate whether the radio is transmitting or receiving.

The software used is SVXLink, a Linux port of the Echolink software. This app allows hams the world over to connect to very distant radios over the Internet.

You can check out the video demos of the system below.

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RasPi “Inception” CD-ROM Case Mod

February 1, 2014 by Marsh 9 Comments

raspiInception

At first glance, [John’s] CD-ROM RasPi case may not seem all that unique, but we like both the implementation as well as the end-result functionality it provides. His goal was to use the Pi as a torrent downloader, and to store the downloaded files on a shared network drive. The Pi drive would slide into a bay in the server’s case—hence the Inception reference: a computer in a computer—allowing downloads while putting another step between the server and the outside world keeping, as well as guaranteeing that the network share would be available, because the server and the Pi would use the same power source.

[John] gutted the CD-ROM’s internals to leave only the PCB, which he stripped of most everything save for the power connector in the back. He then used the base of his old RasPi case as a standoff, mounting it to the top of the CD-ROM’s PCB. He soldered the power lines to the ROM’s power connector and temporarily hooked up a 5V adapter until he gets the server running. The final step was to carve out the back of the case for access to the Ethernet and USB ports, which [John] accomplished with a dremel, a hacksaw and a file. The front of the case still looks like a stock CD-ROM drive, and [John] has plans for future mods: re-purposing the LED to show network activity and modifying the buttons to serve as a reset, pause, or start for torrent downloads.

FFT On The Raspi’s GPU

January 31, 2014 by Brian Benchoff 17 Comments

fft

The Raspberry Pi has been around for two years now, and still there’s little the hardware hacker can actually do with the integrated GPU. That just changed, as the Raspberry Pi foundation just announced a library for Fourier transforms using the GPU.

For those of you who haven’t yet taken your DSP course, fourier transforms take a function (or audio signal, radio signal, or what have you) and output the fundamental frequency. It’s damn useful for everything from software defined radios to guitar pedals, and the new GPU_FFT library is about ten times faster at this task than the Raspi’s CPU.

You can get a copy of the GPU_FFT library by running rpi-update on your pi. If you happen to build anything interesting – something with a software defined radio or even a guitar pedal – you’re more than welcome to send it in to the Hackaday tips line. We’d love to see what you’re up to.

Pan Flute Hero

January 30, 2014 by Marsh 21 Comments

panflutehero

The latest creation in the never-ending collection of “____ Hero” instruments is this Raspi-infused pan flute, built by [Sven Andersson] and his team at the 2013 WOW Hackathon. The flute itself consists of varying lengths of bamboo from a local flower shop, cut short enough to be hand-held while still hiding the Pi from the front side. In the spirit of other ‘Hero’ instruments, the pan flute has no real musical functionality. Each pipe houses what appears to be an electret microphone breakout board, which they kept in place by sealing off the end of the pipe with glue.

The sensors connect to the GPIO connector on the Raspi, which communicates to a local TCP/IP server the team ran as a controller hub. The game is also their original creation, written entirely in LUA. They turned to Spotify to find suitable material for the player to experience, creating playlists with actual pan flute songs and using the libspotify SDK to access the music. You can see the end result of the project in a short demo video below.

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S.A.M. The Safety Attention Monitor

January 30, 2014 by James Hobson 19 Comments

Capture

Last term’s project at Chico State University hopes to reduce driver distraction by alerting you when it notices you aren’t paying attention (to the road!).

The team designed SAM using OpenCV to track your face in order to recognize when you aren’t watching the road. It alerts you through a variety of audible beeps and LED lights, and is programmed to only alert you after set time values — i.e. it’s not going to go off when you’re checking your blind spot, unless you’ve been checking it for over a certain length of time. It also has a silence button you can press for situations like looking around while you are parked.

The proof of concept device was built using a Raspberry Pi, the PiCam, and a breadboard to accommodate some manual controls, the buzzer, and LEDs. It also continuously records video of you on a 30 second loop, and in the event of an accident, it saves all the video — perhaps proving it was your fault. Can you imagine if all cars had this installed? On the plus side you wouldn’t have to argue with insurance companies — but if it really was your fault, well then you’re straight out of luck.

Make Me A Drink, Drinkmo.

January 21, 2014 by James Hobson 26 Comments

[Cabe Atwell’s] latest project is a work of art. Let us introduce the Drinkmotizer: a Raspberry Pi Drink Mixing Robot.

As [Cabe] says, almost every engineer has a drink-mixing robot on their project todo list. We’d probably have to agree; they’re functional, cool, and useful at parties.

You need the Drinkmotizer at your party… At some point, dexterity for drink mixing is lost at a gathering.

Drinkmo is your designated, sober, mixologist.

Your enabler.

Your friend.

Drinkmo works by rotating a long leadscrew that moves the mixing glass from bottle to bottle. The entire setup is made using aluminum extrusion, and is by nature, completely expandable. On the top shelf are gravity fed shot dispensers, controlled by 12VDC car lock actuators. The chaser station (at the end, on the right) works differently. The chaser bottle is actually pressurized by a paintball gun tank and dispensed using a solenoid valve. We hope he’s got a pressure regulator in there, considering the pressure capacity of paintball tanks can range from anywhere from 1000-3000PSI!

The entire system is controlled by a Raspberry Pi running Raspbian, and [Cabe] is using Tkinter for the GUI of the program. He’s got tons of info on the original forum post linked above (including the schematic!), and if you stick around after the break, there’s a very well produced video of Drinkmo in all its glory.

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