Solving A Rubik’s Cube With Just Two Motors

December 2, 2017 by Dan Maloney 11 Comments

We’ve all seen videos of Rubik’s cube champions who can solve the puzzle in less than 5 seconds. And there are cube-twisting robots that can solve the cube even faster, often in under a second. This Rubik’s cube solver is not one of those robots, but it’s still pretty cool.

The reason we like Dexter Industries’ “BricKuber” is not for its lightning speed — it takes a minute or two to solve the puzzle. What we like is the simplicity of the approach to manipulating the cube. Built from LEGO parts, including Mindstorms motors and a BrickPi controller, the BricKuber uses only two motors to work the cube. One motor powers a square turntable upon which the cube sits, while the other powers an arm that does double duty — it either clamps the cube so the turntable can rotate a layer, or it rakes the cube to flip it 90° on the turntable. With a Pi Cam overhead, the rig images all six faces, calculates a solution to the cube, and then flips and twists the cube to solve it. It’s simultaneously mind-boggling and strangely relaxing to watch.

All the code is open source, and we strongly suspect a similar and possibly faster robot could be built without the LEGO parts. You might even be able to build one with popsicle sticks and an Arduino.

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Purely Functional Selfies: Thermal Printer Speaks Haskell

December 1, 2017 by Kristina Panos 6 Comments

[Dan] recently got a cheap POS thermal printer to chooch remotely over ESP32. Having conquered that project, he decided to see what else he could get the printer to do. Why not use it to print pictures? Sure, it’s been done, but not with Haskell. And yeah, the pictures will be grainy and weird-ish and limited to black and white, but hey, we love black and white around here as much as the idea of doing something simply because you can.

In the first project, [Dan] had to figure out how to talk to the printer since the RS422 cable it came with didn’t seem to work. He bought a TTL-to-RS485 adapter, but then realized he could use TTL directly and wired up a ESP32/OLED dev board to it. During the course of turning it into a photo booth, he had to switch to a bigger screen with a better refresh rate.

Unfortunately, [Dan] was unable to use Haskell by itself. He blames this on the cobwebs in the Haskell ecosystem, something that isn’t a problem for languages like Python that celebrate wide usage and support. [Dan] wrote a Python script that handles image capturing, display, and listening for touch activity on the screen, but Haskell ultimately controls the printer. Check out [Dan]’s demo after the break.

This project may have been trying at times, but at least [Dan] didn’t have to give it a brain transplant to get it to do what he wanted.

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Pi Replaces Keiko-chan

November 30, 2017 by Anool Mahidharia 20 Comments

[Tobias Kuhn] and a handful of colleagues at his workplace built Crystal Signal Pi, a Raspberry Pi based low-cost alternative for a notification device that provides visual, audio and network warnings about server problems. [Tobias] works for a Japanese company where it is critical for their servers to keep humming nicely all the time. Any emergencies or error conditions must be broadcast immediately so the technicians can fix it ASAP. Network enabled warning light stalks are used to provide these alerts. A local company produces a series of indicator and hazard warning lights which are colloquially called as Keiko-chan. These are similar to the hazard warning tower lights commonly fixed on machines on factory floors or many kinds of vehicles such as fork lifts. The Kieko-chans add a few bells and whistles making them more suitable for use in the server data centre — a Gigabit LAN port for wired networks and a USB port for WiFi modules. So, besides visual and audio warnings, it can also transmit messages over the network to alert the maintenance folks. Using this commercial solution should not have been a problem were it not for their rather hefty price tag of almost $500 per pop.

So [Tobias] decided to build his own warning lights based around the Raspberry Pi. After two rounds of prototypes, a simple HAT was designed that could be plugged in to a Pi. Details of the hardware are sketchy, but it’s simple enough to figure out. The part list consists of a PLCC-6 style RGB LED, three transistors to drive the three LED pins, a voltage regulator with a couple of electrolytic capacitors and a large push button. A simple acrylic case, and an acrylic cylinder mounted on top of the RGB LED creates a nice edge lit effect for the indicator.

The code for the Crystal Pi is hosted on Github, and includes handy scripts to make installation easy. Once installed, the Crystal Pi can be accessed and controlled either through a web-based GUI or via the API. There are some more interesting features already implemented or scheduled for later, so do check out the blog and the repository for more. Check out the video below to see the Crystal Pi in action.

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Classic Furby Plus Alexa Equals… Furlexa

November 30, 2017 by John Baichtal 19 Comments

[Zach Levine] wrote in to share a project just completed: a classic Furby packing a Raspberry Pi running Alexa: he calls it Furlexa.

The original Furby product wowed consumers of the 90s. In addition to animatronic movements, it also packed simulated voice learning technology that seemed to allow the Furby to learn to speak. It wasn’t like anything else on the market, and even got the toy banned from NSA’s facilities in case it could spy on them. Elegantly, the robot uses only one motor to move all of its parts, using a variety of plastic gears, levers, and cams to control all of the robot’s body parts and to make it dance.

Over the past twenty years the Furby has earned the reputation as one of the most hackable toys ever — despite its mystery microcontroller, which was sealed in plastic to keep the manufacturer’s IP secret. [Zach] replaced the control board with a Pi Zero. He also replaced the crappy mic and pizeo speaker that came with toy with a Pimoroni Speaker pHat and a better mic.

While classic Furbys have a reputation for hackability, the new ones aren’t immune: this Infiltrating Furby is based on a recent model of the toy. Continue reading “Classic Furby Plus Alexa Equals… Furlexa” →

Rage Against The Dying Of The Light With A Raspi Night Vision Camera

November 29, 2017 by Kristina Panos 8 Comments

One of the most interesting things about hacking is the difference between the vision we have at the beginning and the reality of we’ve built at the end. What began as a simple plan to build a night vision VR headset turned into a five-month adventure for [facelessloser] that culminated in this great-looking camera. He thought it would be easy, but almost every aspect presented some kind of challenge. The important thing is that he kept at it.

One of the major issues [facelessloser] encountered was power. He found that the Pi (Zero W), the screen, and the IR LEDs draw between 1.5 and 2A altogether. He was able to solve this one by using the charging board from a 2A power bank paired with a 1200mAh Li-Po built for the high draw required by vaping. If not for space issues, he might have used a 18650 or two.

Another challenge he faced was storing the video and images. He’d considered setting up the Pi as an access point to view them from a phone browser, but ultimately extended a USB port with an OTG cable to use flash drives. With a bit of Python he can watch for the drive to mount and then write to it. If the flash drive suddenly disappears, the Pi starts saving to the SD card.

There are two videos after the break, a walk through and a night vision demo. You’ll see a bit of a lag happening in the demo video—that’s because [facelessloser] is running the feed through PyGame first. No matter what nightlife you want to peep, it might be nice to add automated zoom with a rangefinder or get a closer look with some PiNoculars.

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Bringing MATLAB To A Vacuum Near You

November 23, 2017 by Al Williams 7 Comments

The essence of hacking is modifying something to do a different function. Many of us learned as kids, though, that turning the family TV into an oscilloscope often got you into trouble.

These days, TVs are flat and don’t have high voltage inside, but there’s always the family robot, often known as a Roomba. Besides providing feline transportation, these little pancake-shaped robots also clean floors.

If you don’t want to evict the cat and still get a robust domestic robot platform for experimentation, about $200 will get you a Roomba made to be hacked — the iRobot Create 2. [Gstatum] has a tutorial for using a Raspberry Pi and MATLAB to get one quickly running and even doing basic object recognition using the Pi’s camera.

The code even interfaces with Twitter. The impressive part is the code fits on about a page. This isn’t, however, completely autonomous. It uses a connected phone’s sensor’s so that the phone’s orientation controls the robot’s motion, but the robot does use sensors to prevent driving into walls or falling off a cliff. It also can detect being picked up and uses the Pi’s camera to detect a green flag.

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Play A Claw Machine From Your Armchair

November 19, 2017 by Jenny List 18 Comments

Have you ever been seduced by a claw machine in an arcade, only to have your hopes of a cuddly toy dashed as it fails to hang onto your choice? Then you’re in luck, because now you can play to your heart’s content online. [Ryan Walmsley] wants you to control his Raspberry Pi-driven claw machine.

Hardware-wise he’s replaced the original 8052 microcontroller and relay control with the Pi and a custom H-bridge PCB. We particularly light the warning: “Highish voltage”, and we feel it should appear more often. There is some code in his GitHub repository, but we suspect it doesn’t have everything.

We had a lot of fun digging into the documentation on this one. From his initial thoughts through some prototyping and a board failure, to the launch of the online version and finally a run-down of how it all works, he’s got it covered.

Sadly the machine itself isn’t online all the time, it seems to be only online when [Ryan] is at home, so if you live on the other side of the world from his British base you may be out of luck. Fortunately though his previous live streams are online, so you can see it in action on a past outing below the break.

Of course what kind of swag do you load up in a claw machine like this one? On his Twitter feed we’ve seen tests of the aliens from Toy Story (who start their existence in a claw machine so quite fitting). The majority of items show in is recorded games — now numbering over 2000 — have been our beloved companion cube.

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