Build Your Own LED Glow Poi

Spinning poi is an entertaining pastime, and LEDs can make a great addition to the experience. [MilanDer] built some LED poi of their very own, using a few maker staples along the way.

A 3D printed enclosure is first created, using “clear” PLA that in practice produces translucent white parts. This acts as a great diffuser for the APA102 LEDs inside. The LEDs are driven by an Arduino Pro Mini, which is fitted inside the enclosure along with a buck-boost converter, lithium battery and charge board. Finally, a strap is added to allow the poi to be spun easily by the user.

The visual effect is great, and through the use of an infrared receiver, the poi can be remotely controlled to deliver different RGB animations at the touch of a button. We’d love to see a group of spinners with synchronized colored poi thanks to a master controller, and this hardware would be more than capable of the task.

We’ve seen some advanced networked Poi before, too. If you’ve got a great LED build, be sure to let us know.

Mind Poetry Mindflex Hack

Project Perceives Pondering, Prints Poetry

If poetry is your thing, this hack might convince you that your brain is more advanced than the rest of us poor sots. [Roni Brandini] designed a system that prints lines of poetry when you concentrate. The Mind Poetry project uses an EEG headset from Mattel’s Mindflex toy and pipes your brain’s signals to an Arduino Mega 2560. The system then looks for patterns of brain waves that indicate concentration. As you maintain your concentration, the system continues to print lines of poetry to a small display.

Tapping into the mindflex

[Roni] follows the standard Mindflex hack process by tapping into the data transmission pin on the Mindflex board. Optoisolation is provided by a PC817 to make sure wall power can’t accidentally bleed over into your own wetware. You could get away with just using batteries, but isolation is still a best practice.

The Arduino Brain Library is used to decipher the signal. The Mindflex picks up brain waves from roughly 1 Hz to 50 Hz, which is enough bandwidth to approximately determine mental state. For example, Theta waves are in the 4 Hz to 7 Hz range and can indicate a relaxed, meditative state. Low Beta waves range from 13 Hz to 17 Hz and indicate an alert, focused mental state. The Mindflex system is also generous in that it provides derived meditation and attention scores, ranging from 0 to 100.

It’s difficult to get a high level of precision with this sensor and sampling system, so the code uses [Roni]’s custom recipe of meditation score, attention score, and Low Beta value. He finds it most effective to trigger actions based on a relationship of these scores instead of focusing on the readings themselves. For example, an uptick in both Low Beta waves and the attention score indicate concentration.

Mindflex Brainwave Chart

If the wearer is concentrating, the system prints lines of poetry to the display and charts the three values. As an added gamification, it’ll tell you how many times you broke concentration before you completed the poem. One can imagine a game that tries to break concentration by printing other phrases or even activating an array of mechanical distractions.

If poetry isn’t your thing, you’re in luck. The “Mind Poetry” project also makes some headway (pun intended) with processing the EEG headset’s signals and triggering actions This means you don’t have to be into the poetry scene to reap the benefits. You now have the bones of a hack that lets you control things with your brain muscles and without your muscle muscles.

For inspiration, check out some other Mindflex hacks that let you order drinks with your mind (recommended), shock the heck out of people (not recommended), or even move around your skirt (uh… you do you?).

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Custom Bases Make LEGO Spacecraft Even Cooler

If you’re reading Hackaday, we’re willing to bet that you either own the LEGO Saturn V and Lunar Module models, or at the very least know somebody who does. Even if you thought you’d finally outgrown playing with little plastic bricks (a critical mistake, but one we’ll ignore for now), these two kits just have an undeniable appeal to them. You might never get a chance to work for NASA, but you can at least point to the Saturn V rocket hanging on your wall and say you built it yourself.

[Ben Brooks] thought these fantastic models deserved equally impressive stands, so he built “exhaust plumes” that both craft could proudly perch on. With the addition of some RGB LEDs and a Particle Photon to drive them, he added incredible lighting effects that really bring the display to life. There are also sound effects provided by an Adafruit Audio FX board, and for the Lander, an LCD display that mimics the Apollo Guidance Computer DSKY that astronauts used to safely navigate to the Moon and back.

In his write-up on Hackaday.io, [Ben] makes it clear that he was inspired by previous projects that added an illuminated column of smoke under the LEGO Saturn V, but we think his additions are more than worthy of praise. Playing real audio from the Apollo missions that’s synchronized to the light show honestly makes for a better display than we’ve seen in some museums, and he even rigged up a wireless link so that his neighbor’s kids can trigger a “launch” that they can watch from their window.

For the Lunar Module, he 3D printed an enclosure for the Photon and Adafruit quad alphanumeric display that stands in for the DSKY. There’s even lighted indicators for the 1201/1202 program alarms that popped up as Neil Armstrong and Buzz Aldrin descended to the lunar surface 50 years ago.

While many of us aren’t old enough to have our own first hand memories of the Moon landing, projects like this prove that the incredible accomplishments of the Apollo program never fail to inspire. Who knows? Those kids that are watching [Ben]’s Saturn V from next door might one day get to make the trip themselves.

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A (Card) Table-Top Turing Machine Of Magic: The Gathering Cards

Within normal rules of collectible card game Magic: The Gathering a player may find themselves constrained to only a single legal course of action forward. It’s a situation players could craft to frustrate their opponents, though the victims usually break free after a few moves. But under a carefully crafted scenario, players would have no choice but to become the execution engine for a Turing-complete programming language written with Magic cards via techniques detailed in this paper.

One of the authors of this paper, [Alex Churchill], started working on this challenge in 2010. We covered an earlier iteration of his work here, and his own criticism that it was dependent on player cooperation. At various points, the game rules state a player “may” take certain actions and the construct falls apart if our player chooses the wrong thing. It would be as if a computer was built out of transistors that “may” switch as commanded or not, which would not be a very reliable method of computation.

To improve reliability of this particular Turing machine execution engine, the team combed through rules and cards to devise an encoding where the player is only ever presented with a single legal course forward. This ensures deterministic execution of the instruction stream, and now with proof of Turing-completeness in hand, we congratulate [Alex] on a successful conclusion to his decade-long quest.

We have a primer available for anyone who wants a refresher on Turing machines. They are utterly impractical but fun for hackers to build, and they are typically constructed of electronics and LEDs instead of ink on cardboard.

Via Ars Technica, who have presented their own analysis of this machine.

Main image: Unspecified set of Magic: The Gathering cards by [Robert] CC BY 2.0

Tic-Tac-Toe, In TTL

We’ll all be familiar with Tic-Tac-Toe, or Noughts and Crosses, a childhood pencil-and-paper diversion which has formed the basis of many a coding exercise. It’s an easy enough task to implement in software, but how many of us have seen it done in hardware alone? That’s just what [Warren Toomey] has done using TTL chips, and his method makes for a surprisingly simple circuit.

At its heart is an 8 kB ROM that contains precomputed move sequences that are selected via an address composed of the game states for both player and machine. A series of flip-flops control and buttons to make the board, and a 555 provides a clock.

The technique of using a ROM to replace complex logic is a very powerful one that is facilitated by the low price of relatively large devices that would once have been unaffordable. We’ve seen the technique used elsewhere, including as an ALU in a TTL CPU, and even for an entire CPU in its own right.

You can see the result in operation in the video below the break, and should you wish to have a go for yourself all the relevant information can be found in a GitHub repository.

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This Upgraded Power Wheels Toy Is Powerful Enough To Need Traction Control

A Lamborghini Aventador Is beyond the budget of all but the most well-heeled fathers, but [CodeMakesItGo] came pretty close with a gift for his young son. It was a Lamborghini Aventador all right, but only the 6V Power Wheels ride-on version. As such it was laclustre even for a youngster in its performance, so he decided to give it a 12V upgrade. This proved to have enough grunt to cause wheelspin on those hard plastic wheels, so a further upgrade was a traction control system featuring a NodeMCU. No other child has such a conveyance!

Veterans of the Power Racing Series or Hacky Racers might have expected to see a Chinese motor controller in the mix, but instead he’s used a set of relays for simple on-off control. The traction control has a pair of 3D-printed sensor wheels that operate upon a correspondingĀ  pair of optocouplers to provide feedback to the NodeMCU. A set of different drive options were tried, with finally an H-bridge board being found to be most reliable.

The video below the break shows the hardware, and goes into some detail on the software. The NodeMCU’s WiFi is used to provide some tweakability to the system on the go. The traction control turns out to lower the standing start speed a little, but makes the machine more controllable by its driver. he certainly seems happy with his toy!

Long-time readers will know this isn’t the first Power Wheels upgrade we’ve shown you.

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Coffee Tables, Computers, And Railways

If you were a British kid at any time from the 1950s to the 1980s, the chances are that your toy shop had a train set in it. Not just any train set, but a full model railway layout in a glass case roughly the size of a pool table, with a button that when pressed started a timer and set a little tank engine off on a circuit with a pair of coaches. Magical for a generation raised on black-and-white TV, but probably not something that would cut it with today’s youth. A modern take on the glass-case layout comes from [Jack Flynn], who has created a coffee table with an automated and computerised N-gauge railway layout inside it. And this is definitely a railway rather than a railroad, the main locomotive is a Brush Type 4, a British Rail Class 47 diesel.

The modelling is a work of art, with a slightly idealised British street scene in an oval of double track against a backdrop of a rocky hillside. In the hill is an unexpected surprise which you can see on the video we’veĀ  placed below the break, and beneath it lie the electronics. A Teensy handles the track switching and all the various LED lights around the board, a Sprog DCC controller takes care of the trains, and overseeing everything is a Raspberry Pi running some custom software in Python with a web interface for control. We probably wouldn’t be able to resist a bit of remote-control railway action if our coffee table had a layout like this one!

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