Posts with «misc hacks» label

Air Bubble Characters Float Along This Unique Scrolling Display

We’ve seen a lot of unique large-format scrolling message boards on these pages, but most of them use some sort of established technology – LEDs, electromechanical flip-dots, and the like – in new and unusual ways. We’re pretty sure this air-bubble dot matrix display is a first, though.

While it may not be destined for the front of a bus or a train station arrivals and departures board, [jellmeister]’s bubble display shows some pretty creative thinking. It started with a scrap of multiwall polycarbonate roofing – Corotherm is the brand name – of the type to glaze greenhouses and other structures. The parallel tubes are perfect for the display, although individual tubes could certainly be substituted. A plastic end cap was fabricated; air nozzles in each channel were plumbed to an air supply through solenoid valves. An Arduino with a couple of motor driver hats allows pulses of air into each channel to create reasonably legible characters that float up the tube. The video below shows it in use at a Maker Faire, where visitors could bubble up their own messages.

It took some tweaking to get it looking as good as it does, but there’s plenty of room for improvement. We wonder whether colored liquid might help, or perhaps adding a Neopixel or even a laser to each channel to add some contrast. Maybe something to cloud the water slightly would help; increasing the surface tension with a salt solution might make the bubbles more distinct. We doubt it’ll ever have the contrast ratio of a flip-dot display, but it certainly has a charm all its own.

Treasure Trove of Projects Provides Endless Examples

Sometimes, traveling the internet feels a little like exploring an endless cave system looking for treasure. Lots of dark passageways without light or life, some occasional glimmers as you find a stray gold doubloon or emerald scattered in a corner. If we take the metaphor too far, then finding [Paul]’s “Little Arduino Projects” repository is like turning an unremarkable corner only to discover a dragon’s hoard.

LEAP (as [Paul] also refers to the collection) is a numbered collection of what looks like more or less every electronics project he has completed over the last few years. At the time of writing there are 434 projects in the GitHub repository and tagged and indexed in a handy blog-style interface. Some are familiar, like a modification to a Boldport project. Others are one-off tests of a specific concept like driving a seven segment display (there are actually 16 similar projects if you search the index for “7-Segment”). On the other end are project builds with more detailed logs and documentation, like the LED signboard for monitoring the status of 24 in-progress projects, mounted in a guitar fret board.

LEAP reminds us of the good old days on the internet, before it felt like 50% trolling and 50% tracking cookies. Spend a few minutes checking out [Paul]’s project archive and see if you find anything interesting! We’ve just scratched the surface. And of course, send a tip if you discover something that needs a write-up!

Kinetic Sculpture Achieves Balance Through Machine Learning

We all know how important it is to achieve balance in life, or at least so the self-help industry tells us. How exactly to achieve balance is generally left as an exercise to the individual, however, with varying results. But what about our machines? Will there come a day when artificial intelligences and their robotic bodies become so stressed that they too will search for an elusive and ill-defined sense of balance?

We kid, but only a little; who knows what the future field of machine psychology will discover? Until then, this kinetic sculpture that achieves literal balance might hold lessons for human and machine alike. Dubbed In Medio Stat Virtus, or “In the middle stands virtue,” [Astrid Kraniger]’s kinetic sculpture explores how a simple system can find a stable equilibrium with machine learning. The task seems easy: keep a ball centered on a track suspended by two cables. The length of the cables is varied by stepper motors, while the position of the ball is detected by the difference in weight between the two cables using load cells scavenged from luggage scales. The motors raise and lower each side to even out the forces on each, eventually achieving balance.

The twist here is that rather than a simple PID loop or another control algorithm, [Astrid] chose to apply machine learning to the problem using the Q-Behave library. The system detects when the difference between the two weights is decreasing and “rewards” the algorithm so that it learns what is required of it. The result is a system that gently settles into equilibrium. Check out the video below; it’s strangely soothing.

We’ve seen self-balancing systems before, from ball-balancing Stewart platforms to Segway-like two-wheel balancers. One wonders if machine learning could be applied to these systems as well.

Faux Walkie-Talkie for Comedy Walking Tour is a Rapid Prototyping Win

Chances are good that a fair number of us have been roped into “one of those” projects before. You know the type: vague specs, limited budget, and of course they need it yesterday. But you know 3D-printers and Raspberduinos and whatnot; surely you can wizard something together quickly. Pretty please?

He might not have been quite that constrained, but when [Sean Hodgins] got tapped to help a friend out with an unusual project, rapid prototyping skills helped him create this GPS-enabled faux-walkie talkie audio player. It’s an unusual device with an unusual purpose: a comedic walking tour of Vancouver “haunted houses” where his friend’s funny ghost stories are prompted by location. The hardware to support this is based around [Sean]’s useful HCC module, an Arduino-compatible development board. With a GPS module for localization and a VS1053 codec, SD card reader, and a small power amp for the audio end, the device can recognize when the user is within 50 meters of a location and play the right audio clip. The housing is a 3D-printed replica of an old toy walkie-talkie, complete with non-functional rubber ducky antenna.

[Sean]’s build looks great and does the job, although we don’t get to hear any of the funny stuff in the video below; guess we’ll have to head up to BC for that. That it only took two weeks start to finish is impressive, but watch out – once they know you’re a wizard, they’ll keep coming back.

Dymo Rides Again With This Dot-Matrix Label Embosser

For a five-year-old future Hackaday scribe, there could be no greater day than that on which a Dymo label maker appeared in the house. With its spinny daisy-wheel to choose a character and its squeezy handle to emboss the letter into the plastic tape, there would follow a period of going nuts kerchunking out misspelled labels and slapping them on everything. Plus the things look like space guns, so there would have been a lot of pew-pewing too.

This Dymo dot-matrix label maker bears no resemblance to our long-lost label blaster, but it’s pretty cool in its own right. The product of collaborators [Felix Fisgus] and [Timo Johannes] and undertaken as a project for their digital media program, the only thing the labeler has in common with the Dymos of old is the tape. Where the manual labelers press the characters into the tape with a punch and die, their project uses a dot-matrix approach. Messages are composed on an old PS/2 keyboard through an Arduino and a 16×2 LCD display, and punched onto the tape a dot at a time. The punch is a large darning needle riding on the remains of an old CD drive and driven by a solenoid. When it comes time to cut the label, servo driven scissors do the job. It’s a noisy, crazy, Rube Goldberg affair, and we love it. Check it out in action in the video below.

We applaud [Felix] and [Timo] for carrying the torch of embossed label making. It’s a shame that we’ve turned to soulless thermal printers to handle most of our labeling needs; then again, we’ve seen some pretty neat hacks for those too.

How to Build an Inverter, and Why Not to Bother

It’s ridiculously easy to lay hands on a cheap DC-to-AC inverter these days. They’re in just about every discount or variety store and let you magically plug in mains powered devices where no outlets exist. Need 120- or 240-VAC in your car? No problem – a little unit that plugs into the lighter socket is available for a few bucks.

So are these commodity items worth building yourself? Probably not as [GreatScott!] explains, but learning how they work and what their limitations are will probably help your designs. The cheapest and most common inverters have modified square wave outputs, which yield a waveform that’s good enough for most electronics and avoids the extra expense of producing a pure sinusoidal output. He explains that the waveform is just a square wave with a slight delay at the zero-crossing points to achieve the stepped pattern, and shows a simple H-bridge circuit to produce it. He chose to drive the output section with an Arduino, to easily produce the zero-crossing delay. He uses this low-voltage inverter to demonstrate how much more complicated the design needs to get to overcome the spikes caused by inductive loads and the lack of feedback from the output.

Bottom line: it’s nice to know how inverters work, but some things are better bought than built. That won’t stop people from building them, of course, and knowing what you’re doing in this field has been worth big bucks in the past.

Custom Split-Flap Display Is a Unique Way to Show the Weather

There’s little doubt about the charms of a split-flap display. Watching a display build up a clear, legible message by flipping cards can be mesmerizing, whether on a retro clock radio from the 70s or as part of a big arrival and departure display at an airport or train station. But a weather station with a split-flap display? That’s something you don’t see often.

We usually see projects using split-flap units harvested from some kind of commercial display, but [gabbapeople] decided to go custom and build these displays from the ground up. The frame and mechanicals for each display are made from laser-cut acrylic, as are the flip-card halves. Each cell can display a full alphanumeric character set on 36 cards, with each display driven by its own stepper. An Arduino fetches current conditions from a weather API and translates the description of the weather into a four-character code. The codes shown in the video below seem a little cryptic, but the abbreviation list posted with the project makes things a bit clearer. Bonus points if you can figure out what “HMOO” is without looking at the list.

We like the look and feel of this, but we wonder if split-flap icons might be a neat way to display weather too. It seems like it would be easy enough to do with [gabbapeople]’s detailed instructions. Or you could always look at one of the many other custom split-flap displays we’ve featured for more inspiration.

Semi-automated Winder Spins Rotors for Motors

What’s your secret evil plan? Are you looking for world domination by building a machine that can truly replicate itself? Or are you just tired of winding motor rotors and other coils by hand? Either way, this automated coil winder is something you’re probably going to need.

We jest in part, but it’s true that closing the loop on self-replicating machines means being able to make things like motors. And for either brushed or brushless motors, that means turning spools of wire into coils of some sort. [Mr Innovative]’s winder uses a 3D-printed tube to spin magnet wire around a rotor core. A stepper motor turns the spinner arm a specified number of times, pausing at the end so the operator can move the wire to make room for the next loop. The rotor then spins to the next position on its own stepper motor, and the winding continues. That manual step needs attention to make this a fully automated system, and we think the tension of the wire needs to be addressed so the windings are a bit tighter. But it’s still a nice start, and it gives us some ideas for related coil-winding projects.

Of course, not every motor needs wound coils. After all, brushless PCB motors with etched coils are a thing.

Hack a Day 17 Aug 16:30

RGB Sensor’s New Job: Cryptocurrency Trade Advisor

[XenonJohn] dabbles in cryptocurrency trading, and when he saw an opportunity to buy an RGB color sensor, his immediate thought — which he admitted to us would probably not be the immediate thought of most normal people — was that he could point it to his laptop screen and have it analyze the ratio of green (buy) orders to red (sell) orders being made for crypto trading. In theory, if at a given moment there are more people looking to buy than there are people looking to sell, the value of a commodity could be expected to go up slightly in the short-term. The reverse is true if a lot of sell orders coming in relative to buy orders. Having this information and possibly acting on it could be useful, but then again it might not. Either way, as far as out-of-left-field project ideas go, promoting an RGB color sensor to Cryptocurrency Trading Advisor is a pretty good one.

Since the RGB sensor only sees what is directly in front of it, [XenonJohn] assembled a sort of simple light guide. By enclosing the area of the screen that contains orders in foil-lined cardboard, the sensor can get a general approximation of the amount of red (sell orders) versus green (buy orders). The data gets read by an Arduino which does a simple analysis and sends alerts when a threshold is crossed. He dubbed it the Crypto-Eye, and a video demo is embedded below.

Could this have been done purely in software? Certainly, but there’s a certain charm to the Crypto-Eye being a standalone device that uses a simple visual input to make buy and sell predictions like a Speak & Spell.

Inventive crypto trading is just a side project for [XenonJohn], he’s better known around these parts for his outstanding contributions to one-wheeled electric vehicles, like this 3000W Electric Unicycle, which also happens to feature an Arduino with 80’s-style voice feedback, just like the Crypto-Eye.

Lasers, Mirrors, and Sensors Combine in an Optical Bench Game

Who would have thought you could make a game out of an optical bench? [Chris Mitchell] did, and while we were skeptical at first, his laser Light Bender game has some potential. Just watch your eyes.

The premise is simple: direct the beam of a colored laser to the correct target before time runs out. [Chris] used laser-cut acrylic for his playfield, which has nine square cutouts arranged in a grid. Red, green, and blue laser pointers line the bottom of the grid, with photosensors and RGB LEDs lining the grid on the other three sides. Play starts with a random LED lighting up in one of the three colors, acting as a target. The corresponding color laser comes on, and the player has to insert mirrors or pass-through blocks in the grid to create a path to the target. The faster you hit the CdS cell, the higher your score. It’s simple, but it looks really engaging. We can imagine all sorts of upgrades, like lighting up two different targets at once, or adding a beamsplitter block to hit two targets with the same color. Filters and polarizers could add to the optical fun too.

We like builds that are just for fun, especially when they’re well-crafted and have a slight air of danger. The balloon-busting killbots project we featured recently comes to mind.