A Jukebox For The 21st-Century Kit Blends Raspberry Pi, Sonos, QR Codes

When [Chris Campbell]’s children wanted to play an album in the background over dinner, switching the outputs on his family’s Sonos sound system was perhaps too involved for their budding mastery of technology. This got him thinking about using kid-friendly inputs so they could explore his music collection. Blending QR codes, some LEGO, and a bit of arts and crafts, a kid-friendly QR code reader media controller comes out!

Working with a Raspberry Pi 3 Model B and a cheap camera, [Campbell] whipped up some code to handle producing and reading the QR codes — though he’s running the media server on another computer to maintain fast response times. Once [Campbell] had his QR codes, he printed them out and got his kids involved in cutting and gluing the double-sided cards. Additional cards access different functions — starting a playlist queue, switching output channels, and full album playback, among others. Cue spontaneous dance-parties!

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Pulling Music Out Of Thin Air with a Raspberry Pi

Pianos are great instruments, but being rather heavy and requiring a fair amount of space they are certainly not known for their convenience. Sure, there are more portable varieties available, but they rarely resemble the elegance and classiness of a grand piano. One option is of course to build a downscaled version yourself — and since you’re already customizing the instrument, why stop at the way you play it. [2fishy] didn’t stop there either and ended up with a wooden, space friendly, light controlled piano housing a Raspberry Pi.

Inspired by the concept of a laser harp, [2fishy] followed the same principle but chose a simpler and safer alternative by using LEDs instead. For each playable tone, a LED is mounted opposite a light dependent resistor, creating an array of switches that is then connected to the Raspberry Pi’s GPIO pins. A Python script is handling the rest, polling the GPIO states and — with a little help from pygame, triggering MIDI playback whenever the light stream is interrupted.

There are enough LED/LDR pairs to play one full octave and have some additional control inputs for menu and octave shifting. This concept will naturally require some adjustments to your playing — you can get an idea of it in the demonstration video after the break. And if this design is still not the right size for you, or if you prefer to play in total darkness, this similar MIDI instrument using ultrasonic distance sensors could be of interest.

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Raspberry Pi Zero Drives Tiny RC Truck

We’re not sure which is more fun – putting together a little RC truck with parts laying around on your workbench, or driving it around through a Linux terminal. We’ll take the easy road and say they’re both equally fun. [technodict] had some spare time on his hands and decided to build such a truck.

He started off with a great little chassis that can act as the base for many projects. Powering the four motors is a cheap little dual H bridge motor driver and a couple rechargeable batteries. But the neatest part of this build is that it’s controlled using a little bit of python and driven directly from a terminal, made possible by the Raspberry Pi Zero of course.

With Raspberry Pi Zero now having built in WiFi and Bluetooth – we should see a lot more projects popping up with one at its heart. Be sure to visit [technodict’s] blog for full source and details. And let us know how you could use that little chassis for your next mobile project!

Firing up 750 Raspberry Pis

Creating Raspberry Pi clusters is a popular hacker activity. Bitscope has been commercializing these clusters for a bit now and last year they created a cluster of 750 Pis for Los Alamos National Labs. You might wonder what an institution know for supercomputers wants with a cluster of Raspberry Pis. Turns out it is tough to justify taking a real high-speed cluster down just to test software. Now developers can run small test programs with a large number of CPU cores without requiring time on the big iron.

On the face of it, this doesn’t sound too hard, but hooking up 750 of anything is going to have its challenges. You have to provide power and carry away heat. They all have to communicate, and you aren’t going to want to house the thing in a few hundred square feet which makes heat and power even more difficult.

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Roll Your Own Raspberry Pi OS

Writing an operating system is no small task, but like everything else it is easier than it used to be. [JSandler] has a tutorial on how to create a simple operating system for the Raspberry Pi. One thing that makes it easier is the development environment used. QEMU emulates a Raspberry Pi so you can do the development on a desktop PC and test in the virtual environment. When you are ready, you can set up a bootable SD card and try your work on a real device.

The operating system isn’t very complex, but it does boot, organize memory, displays on the screen, handles interrupts, and manages processes. What else do you need?

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Overclock Your Raspberry Pi The Right Way

The Raspberry Pi came upon us as an educational platform. A credit card sized computer capable of running Linux from a micro SD card, the Raspberry Pi has proven useful for far more than just education. It has made its way into every nook and cranny of the hacker world. There are some cases, however, where it might be a bit slow or seem a bit under powered. One way of speeding the Raspi up is to overclock it.

[Dmitry] has written up an excellent overclocking guide based upon Eltech’s write up on the subject. He takes it a bit further and applies the algorithm to both Raspi 2 and Raspi 3. You’ll need a beefier power supply, some heat sinks and fans – all stuff you probably have lying around on your workbench. Now there’s no excuse stopping you from ratcheting up the MHz and pushing your Pi to the limit!

We’ve seen several guides to overclocking the Raspi here on Hackaday, including the current record holder. Be sure to check out [dmitry’s] IO page for the overclocking details, and let us know of any new uses you’ve found by overclocking your Raspi in the comment below.

Raspberry Pi Offers Soulless Work Oversight

If you’re like us, you spend more time than you care to admit staring at a computer screen. Whether it’s trying to find the right words for a blog post or troubleshooting some code, the end result is the same: an otherwise normally functioning human being is reduced to a slack-jawed zombie. Wouldn’t it be nice to be able to quantify just how much of your life is being wasted basking in the flickering glow of your monitor? Surely that wouldn’t be a crushingly depressing piece of information to have at the end of the week.

With the magic of modern technology, you need wonder no longer. Prolific hacker [dekuNukem] has created the aptly named “facepunch”, which allows you to “punch in” with nothing more than your face. Just sit down in front of your Raspberry Pi’s camera, and the numbers start ticking away. It’s like the little clock in the front of a taxi: except at the end you don’t have to pay anyone, you just have to come to terms with what your life has become. So that’s cool.

It doesn’t take much hardware to play along at home. All you need is a Raspberry Pi and the official camera accessory. Though for the full effect you should add one of the displays supported by the Luma.OLED driver so you can see the minutes and hours ticking away in real-time.

To get the facial recognition going, all you need to do is take a well-lit picture of your face and save it as a 400×400 JPEG. The Python 3 script will take care of the rest: checking the frames from the camera every few seconds to see if your beautiful mug is in the frame, and incrementing the counters accordingly.

Even if you’re not in the market for an Orwellian electronic supervisor, this project is a great example to get you started in the world of facial recognition. With a little luck, you’ll be weaponizing it in no time.