Raspberry Pi

1884 Articles

Clustering A Lot Of Raspberry Pi Zeros

September 18, 2016 by 57 Comments

It became something of a cliché a few years ago in online discussions, whenever a new single board computer was mentioned someone would pop up and say something like “Imagine a Beowulf cluster…“. Back then it was said largely in jest, but with the current generation of boards it’s a distinct possibility. Who hasn’t looked at a Raspberry Pi and idly thought about a cluster of them, or even created one!

[Electronoob] did just that, creating a variety of Raspberry Pi cluster configurations, the most impressive of which is a stack of 32 Pi Zeros mounted together with stand-offs. The plan was to network it via USB, for which he initially considered building a backplane, but was put off by the cost of vertical USB connectors and instead went for a wired approach. If there is a lesson to be learned from his experiences it is that buying very cheap USB cables is a minefield: his pile of eBay specials turned out to have significant numbers of faults. He’s now faced with a stark choice, solder  32 sets of USB pads on the base of each Zero or buy better cables.

The stack of Zeros is pretty impressive, but so what, you think. It’s still not working properly. But the Zero cluster isn’t his only work. He’s also created a set of very nicely executed Ethernet clusters using the larger Pi boards, and the way he’s mounted them on top of compact Ethernet switches sets them apart from some of the more spaghetti-like Pi clusters.

It’s true a Pi cluster won’t cut it in the world of supercomputers, you could almost certainly buy more bang for your buck without too much effort. But it does represent a very accessible way to learn about cluster computing, and you have to admit it a stack of Zeros does look rather impressive.

We’ve seen quite a few Pi clusters here since 2012, the biggest of which is probably this 120 node behemoth, complete with screens.

Hackaday Prize Entry: AutoFan Saves Tired Drivers With Face Recognition

September 17, 2016 by 10 Comments

Long distance driving can be tedious at times. The glare of the sun and the greenhouse effect of all your car’s windows make it hot and dry. You turn on the fan, or air conditioning if you have it, and that brings relief. Soon enough you’ve got another problem, the cold dry air is uncomfortable on your eyes. Eventually as you become more tired, you find yourself needing the air on your face more and more as you stay alert. You thus spend most of the journey fiddling with your vents or adjusting the climate controls. Wouldn’t it be great if the car could do all that for you?

AutoFan is a project from [hanno] that aims to automate this process intelligently. It has a fan with steerable louvres, driven by a Raspberry Pi 2 with attached webcam. The Pi computes the position of the driver’s face, and ensures the air from the fan is directed to one side of it. If it sees the driver’s blink rate increasing it directs the air to their face, having detected that they are becoming tired.

The build logs go into detail on the mathematics of calculating servo angles and correcting for camera lens distortion in OpenCV. They also discuss the Python code used to take advantage of the multicore architecture, and to control the servos. The prototype fan housing can be seen in the video below the break, complete with an unimpressed-looking cat. For those of you interested in the code, he has made it available in a GitHub repository.

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SNES Micro Is A Pi Z Of Art

September 11, 2016 by 11 Comments

Clay is a shapeless raw material that’s waiting to be turned into awesomeness by your creativity. So is the Raspberry Pi. [Dorison Hugo] brought the two together in his artfully crafted SNES micro – a tiny retro gaming console sculpted from clay.

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Raspberry Pi Plays All That Jazz

September 10, 2016 by 14 Comments

[James Bellafaire] wanted a good looking old radio with a modern sound. Granted, you could hollow the case out and replace it with an iPod. Or you could convert the thing to an Internet radio. But where’s the fun in that?

[James] took a different approach. Part woodworking project, part Raspberry Pi project, and part microcontroller project, he wound up with a hard drive-based music player in a 1930’s case with knobs that control the playback.

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Landscape Lighting That Also Texts

September 9, 2016 by 5 Comments

Your local hardware store or garden supply center probably has everything you need to install landscape lighting all around your property. What’s a little less likely is coming out of that situation with fewer holes in your wallet than in your yard. And even then, it’s pretty much guaranteed that any off-the-shelf equipment won’t send you a text message when your landscape lighting isn’t working properly. [Mark]’s landscape lighting system does, though!

Powered by a Raspberry Pi, this landscape lighting system has every feature imaginable. It can turn the lighting on at sunset and turn it off at a set or random time later in the evening. There’s a web interface served from the Pi that allows further user control. The Raspberry Pi also monitors the lighting and can sense when one of the lights burns out. When one does, the Pi uses Twillo to send a text message notification.

There’s not many more features we can imagine packing into a setup like this. Of course, if you don’t have a spare Pi around you can probably manage to get the job done with an ESP8266, or even an old-fashioned Arduino.

Raspberry Pi Radio Streaming Service Guts Yamaha Shelf System

September 9, 2016 by 9 Comments

There are dozens — dozens! — of options to meet your music and streaming needs these days.  Looking to make something of his own that retains that 90’s vibe of having a dedicated stereo system but with modern wireless integration, [thk4711] turned an old Yamaha hifi into a Raspberry Pi streaming client.

As far as the case goes, a few modifications allowed [thk4711] to use all of the existing buttons, and a quick-swap of the back-plate and screen gave him a better enclosure than one he could fabricate himself. The power supply proved to be the most difficult part of the project due in part to some “digital noise” interference between the digital and analog components while they were wired to a common ground. This was solved by implementing two transformers, a LM2596 voltage regulator and a LT1084 low-noise power supply to smooth things out.

The Raspberry Pi 2-centered device supports internet radio, Spotify connect, Airplay, USB and auxiliary inputs.

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Hackaday Prize Entry: Boots And Cats And Boots And Cats

September 8, 2016 by 13 Comments

Electronic drums are pricey, but the drums themselves are actually very easy to make. By simply putting a few piezos on some rubber mats, you can make a set of electronic drums. The real trick, and the expensive bit, is in the drum module. This module has inputs for the high hat, snare, toms, and bass drum to turn the repetitive thwaking of a stick on a rubber mat into drum sounds.

For his Hackaday Prize entry, [Jeremy] isn’t building a set of electronic drums. He’s building a drum module, complete with touchscreen interface and a GUI.

This isn’t [Jeremy]’s first go at building a drum module – his first implementation was RaspiDrums, an add-on for the Raspberry Pi that used accelerometers instead of piezos. The software works well enough with a USB sound card to serve as a set of real electronic snare.

Now [Jeremey] is moving up to a full kit, and the power of the Raspberry Pi means he can easily add a touch screen to his device. Right now the efforts are going into building a GUI using Gtkmm, and wrapping everything up into a front panel that makes sense and is easy to use. The drums themselves are a solved problem, making this Hackaday Prize entry a fantastic polish on an already great project.

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