Hack A PS/2 Keyboard Onto Your Pi Zero

March 2, 2016 by Elliot Williams 31 Comments

Hacking for the Raspberry Pi Zero is a tricky proposition. Whatever you do, you’re working with a nominal five dollar board, so your hacks can’t be too highfalutin. For instance, a decent PS/2 to USB adapter will cost you as much as the Zero did, if not more. But if you just need to drive your Pi Zero from your old Model M (we hear you!) you’ve got to do it on the cheap.

So when prolific Pi hacker [mincepi] set out to build a PS/2 adapter, some corners were cut. PS/2 is a clocked data protocol, but the good news is that the clock doesn’t start and stop all the time as in I2C or SPI. This means that if you poll the data line at just the right frequency, at least in principle you’ll be able to ignore the clock.

So that’s what [mincepi] did. As you can see in the schematic and the banner image, there’s nothing to it. Two resistors provide the pullup voltage for the clock and data lines. And here’s a gem: a green LED with a drop voltage of about 2 V converts the 5 V data line down to something that the Pi Zero’s 3.3 V won’t get fried with. Cute, and very much in keeping with the spirit of the hack. You might be tempted to scrounge up a 3.3 V zener diode from somewhere just to be on the safe side, but remember, it’s a five dollar computer you’re protecting.

The last piece is a custom kernel module for the Pi that polls the PS/2 data line at just the right frequency. If you’re not a Linux person and “compiling a kernel module” sounds scary, [mincepi] has even put together a nice guide for the Raspbian distribution that he’s using. It should work with minor tweaks for any other distro.

We said [mincepi] is a prolific Pi hacker and here’s the proof: we’ve covered his quick-and-dirty VGA output hack and a scheme to get analog sound input into the Pi Zero just in the last couple of weeks. Hack on!

Star Trek Pi

March 1, 2016 by Al Williams 26 Comments

Every time we yell out, “OK Google… navigate to Velvet Melvin’s” we feel like a Star Trek character. After all, you’ve never seen Captain Kirk (or Picard) using a keyboard. If you get that same feeling, and you have a Raspberry Pi project in mind, you might enjoy the Raspberry Pi LCARS interface.

You can see the results in the video below. The interface uses PyGame, and you can customize it with different skins if you don’t want a Star Trek look.

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Mindless Toddler Toy Becomes Teaching Tool

March 1, 2016 by Kristina Panos 8 Comments

If you want to sell a toy for the toddler crowd, it ought to be pretty close to indestructible. A lot of toys out there are just plain nonsense game-wise and therefore waste their beefy potential. [2dom]’s wife was close to throwing out such a toy—a Little Tikes Goofy Ball. The thing literally does nothing but let you push its big buttons in. After some time passes, it pops them back out again and giggles. Game over. [2dom] rescued it from the trash and turned it into a toy that plays math games.

[2dom] removed the existing board and replaced it with an Arduino Pro Mini and a Darlington array that drives the motor that pops the buttons back out, the speaker, and a Nokia 5110 screen. Upon startup, the user chooses between addition, subtraction, and multiplication questions using the appropriate button. Questions appear in the middle of the screen and multiple choice answers in the corners.

Choose the right answer and the ball cheers and shows one of a few faces. Choose the wrong answer and it makes a buzzing sound and shows an X. There is an adaptive level system for the questions that [2dom] doesn’t show in the demonstration video after the break. For every five correct answers, you level up. His 3- and 5-year-olds love it. For more advanced teachable moments, there’s this toy-turned-enigma-machine.

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Building An Interactive LED Lamp To Annoy Yourself

March 1, 2016 by Gerrit Coetzee 12 Comments

[Norwegian Creations] makes things as a business model. Tired of the mundane lamp above their heads, they decided to put their skills to use. The basic idea was simple, plot out a cool 3D function, put some RGB LEDs behind it, make it an awesome mathematical rainbow light display, hang it right above their desks, and then ignore it for their monitors while they worked.

The brains of the project is a Raspberry Pi B+, WS2812 LED strips, and a Fadecandy controller from Adafruit. They 3D printed hexagonal towers out of clear plastic and labeled each carefully. Then they attached the strips to the board, glued on the hexagons, and covered the remaining surface in cotton balls to give it a cloud-like appearance.

The lamp normally plays patterns or maintains a steady light. As the day turns to night it reflects the world outside. However, if someone likes their Facebook page the light has a little one robot strobe party, which we imagine can get annoying over time. Video after the break.

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Be A Hero At Your Next Hackathon With A Foldable CNC

March 1, 2016 by Gerrit Coetzee 10 Comments

Be the hero at your next hackathon with this foldable cnc. When the line for the laser cutter is four teams deep, you’ll come out ahead. It might even be accurate enough to pop out a quick circuit board. Though, [wwwektor] just wanted a CNC that could be taken from storage and unfolded when needed. Sit it on a kitchen table and cut out some ornaments, or hang it from the front door to engrave the house’s address. Who needs injection molded chrome plated numbers anyway?

It’s based around tubular ways, much like other 3D printed CNCs we’ve covered. The design’s portable nature gives it an inherently unstable design. However, given the design goals, this is reasonable. It uses timing belts, steppers, and ball bearings for its movement. The way the frame sits on the table it should deal with most routing tasks without needing adjustment to stay in plane with the surface it’s set-on. As long as you don’t need square edges.

There’s a video of it in operation after the break. We love these forays into unique CNC designs. We never know what new idea we’ll see next.

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Pi 3 Benchmarks: The Marketing Hype Is True

March 1, 2016 by Brian Benchoff 123 Comments

The spec bullet list for the latest Raspberry Pi begins as you’ve already heard: WiFi and Bluetooth, now standard. While this is impressive itself, it doesn’t tell the whole story. The Pi 3, with an ARM Cortex A53, is up to 50% faster than the Pi 2 from last year. That’s an astonishing improvement in just 12 short months.

In playing with the Pi 3 for a few hours, it’s apparent the Pi 3 is fast. It passes a threshold of usability. The Raspberry Pi isn’t a computer that just sits on a shelf and runs a few cron jobs and blinks LEDs anymore – this is a computer that’s usable as a computer. But how fast is it? By stroke of luck, the official website for the Cortex A53 gives us a direct comparison between this chip and the CPU in the Raspberry Pi 2:

In real devices, the performance improvement from the Pi 2 to the Pi 3 is somewhere between 40 and 60 percent. At least that’s what ARM and the Raspberry Pi foundation are claiming. Is this true? There are tests we can run, and the marketing speak, for once, isn’t too terribly off the mark.

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Moore’s Law Is Over (Again)

March 1, 2016 by Elliot Williams 52 Comments

According to this article in Nature, Moore’s Law is officially done. And bears poop in the woods.

Note when the time axis ends... — Note when the time axis ends…

There was a time, a few years back, when the constant exponential growth rate of the number of transistors packed into an IC was taken for granted: every two years, a doubling in density. After all, it was a “law” proposed by Gordon E. Moore, founder of Intel. Less a law than a production goal for a silicon manufacturer, it proved to be a very useful marketing gimmick.

Rumors of the death of Moore’s law usually stir up every couple years, and then Intel would figure out a way to pack things even more densely. But lately, even Intel has admitted that the pace of miniaturization has to slow down. And now we have confirmation in Nature: the cost of Intel continuing its rate of miniaturization is less than the benefit.

We’ve already gotten used to CPU speed increases slowing way down in the name of energy efficiency, so this isn’t totally new territory. Do we even care if the Moore’s-law rate slows down by 50%? How small do our ICs need to be?

Graph by [Wgsimon] via Wikipedia.