3 Nerds + 2 Days = Little Big Pixel

December 3, 2015 by Dan Maloney 2 Comments

Two days at a company sponsored hackathon? Sounds like fun to us! And productive too – the end result for [GuuzG] and two of his workmates from their company’s annual “w00tcamp” was this festive and versatile 16×16 pixel mega display.

From the sound of it, [GuuzG] and his mates at q42.com are not exactly hardware types, but they came up with a nice build nonetheless. Their design was based on 16 WS2812 LED strips for a 256 pixel display. An MDF frame was whipped up with cross-lap joints to form a square cell for each pixel. Painted white and topped with a frosted Plexiglass sheet, each RGB pixel has a soft, diffuse glow yet sharply defined borders. Powered by a pair of 5A DIN rail DC supplies and controlled by a Raspberry Pi, the finished display is very versatile – users can draw random pixel art, play the Game of Life, or just upload an image. [GuuzG] and company are planning to add Tetris, naturally, and maybe a webcam for fun.

We’ve seen lots of uses for the ubiquitous WS2812 LEDs, from clocks to Ambilight clones to ground-effect lighting for an electric skateboard. But if you’re in the mood for a display that doesn’t use LEDs, there’s always this multithreading display.

[via Reddit]

4 Port USB, Raspberry Pi Zero Piggy-Back Hack

December 3, 2015 by Rud Merriam 54 Comments

[Frederick] decided his new Zero needed a USB hub. He noticed a small, on hand, USB hub was the same size as the Zero. As any good hacker would, he stripped it from its case to piggy-back it onto the Zero. What’s with the piggy-backing since we just saw that with another Zero hack that added a WiFi dongle? Is it something in the water? Nah, probably just a natural fit with the mini-sized Zero.

Foam and elastic bands make a next arrangement

Tricky wiring to the hub’s USB

It certainly helps that the USB and power pads on the back of the Zero are available and of a good size to accept direct, soldered wire connections. The USB connections on the hub were a little more tricky. The wires were soldered to the surface mount pins of the mini-B connector. But [Frederick] managed to get that done, also.

A nice advantage of this hack is that a couple of soldered jumper wires let the Zero draw power from the hub’s wall-wart, eliminating one cable from those needed to work with the Pi. Using hot glue for strain relief on the wiring is a nice touch. To keep the boards from shorting he put a piece of foam between them and help them together with elastic bands. Simple and easy.

Shoving A Raspberry Pi Zero Into An Xbox Controller

December 2, 2015 by James Hobson 18 Comments

With the release of the Raspberry Pi Zero last month, we’ve been waiting in excitement to see the first creative hacks to come out, making use of its tiny size; which if you didn’t know, is smaller than a business card. [Terence Eden] hopped to it and made what might be the first Raspberry Pi Zero emulator: inside an Xbox controller.

Thanks to its small size it’s actually a fairly straight forward hack with minimal modification to the controller in order to make it fit. In fact, you only need to remove the memory card holder from the controller and snip one bit of plastic in order to make it fit right in the middle — awesome.

Now it does stick out a bit as you can see in the pictures, but we’re sure it won’t take someone long to make a 3D printed part that snaps into the controller giving it a more stock appearance. Unfortunately since HDMI can’t carry a power source to the Pi, [Terence] is using a micro-USB to power it — but there is enough space inside the controller for a battery pack if you wanted to make it truly portable.

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Pi Zero HackChat With Lady Ada

December 2, 2015 by Mike Szczys 104 Comments

This Thursday, December 3rd, join us for a Live HackChat about the Raspberry Pi Zero with special guest [Limor Fried]. You may know [Limor] as [Lady Ada], the founder of Adafruit Industries. Adafruit has been on the forefront of the Pi Zero release. The $5 single board computer was announced one week ago by the Raspberry Pi Foundation.

Join in the chat to discuss the Raspberry Pi Zero. Limor has done a lot of work with the board already, including hacking analog audio back into the form factor. This is a great opportunity to ask questions, talk about your own plans for the hardware, and to find collaborators for future projects.

Pi Zero HackChat starts Thursday at 5pm PST (here’s a timezone cheat sheet if you need it). Participating in this live chat is very simple. Those who are already part of the Hacker Channel can simply click on the Team Messaging button. If you’re not part of the channel, just go to the hacker Channel page, scroll to the bottom of the “TEAM” list in the left sidebar and click “Request to join this project”.

HackChat takes place in the Hacker Channel every few weeks and is a friendly place to talk about engineering and the projects you’re working on.

Raspberry Pi Zero, Or Minus One?

December 1, 2015 by Rud Merriam 274 Comments

The Wall Street Journal reported that [Eric Schmidt] of Google and now Alphabet Inc, promoted the idea of an inexpensive version of the Raspberry Pi to the Raspberry Pi foundation’s [Eben Upton]. Apparently [Upton] accepted this recommendation despite existing plans to make a more expensive, more powerful version of the Pi. The outcome is the Raspberry Pi Zero that sells, in some places, for $5.00 and was given away for free on the cover of the MagPi magazine.

From the WSJ article:

“He [Schmidt] said it was very hard to compete with cheap. He made a very compelling case. It was a life-changing conversation,” Mr. Upton said, adding that he went back to the lab and scrapped all the engineering plans for more expensive versions of future Pi computers. “The idea was to make a more powerful thing at the same price, and then make a cheaper thing with the same power.”

Plans were scrapped. The more powerful Pi 2 was released at the price point of existing Pis, and now we have the Zero.

Pi’s Purpose

The Raspberry Pi Foundation is a registered educational charity in the UK. The purpose of this Foundation according to their About Us page is to, ‘advance the education of adults and children, particularly in the field of computers, computer science, and related subjects.’

Why is the Raspberry Pi Foundation so concerned about computer education? From the 1990s onward, fewer and fewer A Level students in the UK applying to study Computer Science had previous experience as hobbyist programmers. An applicant in the 2000s usually might have only done a little web design.

Why then does the Raspberry Pi Zero exist? [Upton] also told Cnet, “We really hope this is going to get those last few people in the door and involved in computer programming.”

Very good, but how well does the Zero support this goal or address their concerns?

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Listening To The Sounds Of The Earth

December 1, 2015 by Rud Merriam 19 Comments

A geophone is a specially built microphone for listening to the Earth. [JTAdams] found them at a reasonable price so bought some to play with. A geophone is used to detect vibrations from earthquakes, explosions, rumbling trucks, and vibroseis vehicles. To be useful it needs an amplifier and a recording device to capture the signals.

[JTAdams] used a standard amplifier design for an LT1677 op-amp, fed the signal to an MCP3008 A/D converter, and read the output using a Raspberry Pi. A Python script records the data to a CSV file for processing. The Pi worked well because the entire setup needs to be portable to take into the field. Another Python script plots the data which is made available from a web page. A neat simple way of presenting the raw data. [JTAdams] promises more information in the future on post-processing the data. You don’t need a geophone to detect seismic waves if you build your own, but a real ‘phone will be more rugged.

Oh, what’s a vibroseis? It’s a truck with a big flat plate underneath it. The plate is hydraulically lowered to the ground until the weight of the truck is on it. The truck then causes the plate to vibrate, usually sweeping from around 10 hz to 100 hz. This infrasound pass through the ground until it is reflected back by underlying rock layers. A long string of geophones, think 1,000s of feet, detects the waves, which are recorded. In practice, many trucks are used to generate a synchronized signal of sufficient strength. Or, you can set off an explosion which is the technique used in water. Typically the information is used for oil and gas exploration. A video of one of the trucks in action after the break.

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RasPi LED Panel Library Is Nyan-tastic

November 29, 2015 by Sonya Vasquez 5 Comments

Quick–in a pinch, let’s have ourselves a giant RGB LED Matrix! As marvelous as it sounds, it’s pretty easy to forget that there’s a battle to be won against picking the right parts, debugging drivers, and sorting out our spaghetti wiring. Rest assured, [Hzeller] has done all of the heavy-lifting for us with a Raspberry Pi RGB LED Matrix Implementation that scales to multiple panels and runs on any Pi model to date!

Offering 24-bit color at about 100 Hz for up to a grand total of 36 panels, [Hzeller’s] library is no slouch. The library enables customization of your panel arrangements, and a separate project (also [Hzeller’s] handiwork) makes this setup compatible with the pixel-pusher protocol as a network device.

It’s certainly true that many of us have a thing for these displays, so you might ask: “have we seen this before? What’s all the fuss?” Like the others, the final product is a sight to behold, but [hzeller] and his implementation stands strong because of his phenomenal response to answering the question: how? In fact, almost more impressive is his comprehensive online documentation. Inside, [hzeller] details various hardware configurations for a custom number of panels or a particular flavor of Pi that drives them. He also provides references for pinout quirks and provides out-of-the-box software demos to ensure that anyone can bring this project to life. If a poorly-written or non-existent READMEs have made you shy away from building on an open-source project, fear not. From pinout quirks and out-of-the-box software demos, [hzeller] has covered all the bases and given us a project that folks of all levels of hacking.

Perhaps the best part of this project is the span of the audience that can take something away from it. If you’re a seasoned Linux junkie, dive into the source code to get a good feel of mechanics of how [hzeller] pushes this project onto a single core in a Raspi-2 configuration. If you’re new to digital electronics, let this project be your moment to pick up a Pi, a panel (or four), and run, knowing that [hzeller’s] README is the only tome you’ll need to light up the night.

We had the honor of soaking up some Nyan-Cat rainbows with a live demo at this year’s SuperCon.

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