Have you ever looked around your city’s layout and thought you could do better? Maybe you’ve always wanted to see how she’d run on nuclear or wind power, or just play around with civic amenities and see how your choices affect the citizens.

[Robbe Nagel] made this physical-digital simulator for a Creative Programming class within an industrial design program. We don’t have all the details, but as [Robbe] explains in the video after the break, each block has a resistor on the bottom, and each cubbyhole has a pair of contacts ready to mate with it. An Arduino nestled safely in the LEGO bunker below reads the different resistance values to determine what block was placed where.

[Robbe] wrote a program that evaluates various layouts and provides statistics for things like population, overall health, education level, pollution, etc. As you can see after the break, these values change as soon as blocks are added or removed. Part of what makes this simulator so cool is that it could be used for serious purposes, or it could be totally gamified.

It’s no secret that we like LEGO, especially as an enclosure material. Dress it up or dress it down, just don’t leave any pieces on the floor.

Via r/Arduino

[Ryan Schenk] had a problem: he built the perfect surfboard. Normally that wouldn’t present a problem, but in this case, it did because [Ryan] had no idea how he carved the gentle curves on the bottom of the board. So he built this homebrew 2D-scanner to make the job of replicating his hand-carved board a bit easier.

Dubbed the Scanbot 69420 – interpretation of the number is left as an exercise for the reader, my dude – the scanner is pretty simple. It’s just an old mouse carrying a digital dial indicator from Harbor Freight. The mouse was gutted, with even the original ball replaced by an RC plane wheel. The optical encoder and buttons were hooked to an Arduino, as was the serial output of the dial indicator. The Arduino consolidates the data from both sensors and sends a stream of X- and Z-axis coordinates up the USB cable as the rig slides across the board on a straightedge. On the PC side, a Node.js program turns the raw data into a vector drawing that represents the profile of the board at that point. Curves are captured at various points along the length of the board, resulting in a series of curves that can be used to replicate the board.

Yes, this could have been done with a straightedge, a ruler, and a pencil and paper – or perhaps with a hacked set of calipers – but that wouldn’t be nearly as much fun. And we can certainly see applications for this far beyond the surfboard shop.

Ah, the joys of domestic animals. Often adorable, occasionally useful, they’re universally unable to care for themselves in the slightest. That’s part of the bargain though; we take over responsibility for their upkeep and they repay us with whatever it is they do best. Unless the animal in question is a cat, of course – they have their own terms and conditions.

Chickens, though, are very useful indeed. Give them food and water and they give you delicious, nutritious, high-quality protein. Feeding them every day can be a chore, though, unless you automate the task. This Twitch-enabled robotic chicken feeder may be overkill for that simple use case, but as [Sean Hodgins] tell it, there’s a method to all the hardware he threw at this build. That would include a custom-welded steel frame holding a solar panel and batteries, a huge LED matrix display, a Raspberry Pi and camera, and of course, food dispensers. Those are of the kind once used to dispense candy or gum for a coin or two in the grocery; retooled with 3D-printed parts, the dispensers now eject a small scoop of feed whenever someone watching a Twitch stream decides to donate to the farm that’s hosting the system. You can see the build below in detail, or just pop over to Sweet Farm to check out the live feed and gawk at some chickens.

It’s an impressive bit of work on [Sean]’s part for sure, and we did notice how he used his HCC rapid prototyping module to speed up development. Still, we’re not convinced there will be many donations at $10 a pop. Then again, dropping donations to the micropayment level may lead to overfed chickens, and that’s not a good thing.

We’ve heard of beer pong, but we’re not sure we’ve heard of wine pong. And certainly never wine pong automated with a ping pong ball throwing robot like this one.

There’s not a huge amount of detail available in the video below, and no build log per se. But [Electron Dust] has a few shots in the video that explain what’s going on, as well as a brief description in a reddit thread about the device. The idea is to spin a ball up to a steady speed and release it the same way every time. The rig itself is made of wood and spun by plain brushed DC motors – [Electron Dust] explains that he chose them over PWM servos to simplify things and eliminate uncertainty in the release point. The ball is retained by a pair of arms, each controlled by a pair of hobby servos. An Arduino spins along with everything else and counts 50 revolutions before triggering the servos to retract and release the ball. A glass positioned at the landing spot captures the ball perfectly once everything is dialed in.

Here’s hoping that build details end up on his blog soon, as they did for this audio-feedback juggling machine. And while we certainly like this project, it might be cool if it could aim the ball into the glass. Or it could always reposition the target on the fly.

In 1994, Weezer famously said that “you take your car to work, I’ll take my board”. Obviously, for the office-bound, surfing is simply out of the question during the working day.  That doesn’t mean you can’t have a little fun with a desk toy inspired by the waves.

The crux of the build is a watery diorama, which interacts with a faux-surfboard. The diorama consists of a tank constructed out of plexiglas, sealed together to be watertight. It’s then filled with blue-dyed water, and topped off with baby oil. The tank is then mounted on a cam controlled by a servo, which rocks the tank back and forth to create waves. This is controlled by the motion of the rider on the plywood surfboard, which can be rocked to and fro on the floor thanks to its curved bottom. An Arduino built into the board monitors a three-axis accelerometer, and sends this information to the Arduino controlling the tank.

By riding the board, the user can shake the tank. Get the motion just right, and smooth rolling waves are your reward. Jerk around with no real rhythm, and you’ll just get messy surf. We reckon it would be even better with a little surfer floating in the tank, too. It’s a fun build, and one that might help stave off the negative health effects of sitting at a desk all day. You might prefer a more shocking desk toy, however. Video after the break.

Good science fiction has sound scientific fact behind it and when Tony Stark first made his debut on the big screen with design tools that worked at the wave of a hand, makers and hackers were not far behind with DIY solutions. Over the years the ideas have become much more polished, as we can see with this Gesture Recognition with PIR sensors project.

The project uses the TPA81 8-pixel thermopile array which detects the change in heat levels from 8 adjacent points. An Arduino reads these temperature points over I2C and then a simple thresholding function is used to detect the movement of the fingers. These movements are then used to do a number of things including turn the volume up or down as shown in the image alongside.

The brilliant part is that the TPA81 8-Pixel sensor has been around for a number of years. It is a bit expensive though it has the ability to detect small thermal variations such as candle flames at up to 2 Meters. More recent parts such as the Panasonic AMG8834 that contain a grid of 8×8 such sensors are much more capable for your hacking/making pleasure, but come with an increased price tag.

This technique is not just limited to gestures, and can be used in Heat-Seeking Robots that can very well be trained to follow the cat around just to annoy it.

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.

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!

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.

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.