Automatic Scoring For Skeeball Mini-Golf

November 14, 2020 by Lewin Day 1 Comment

Minigolf is a fun, simple pastime that has the benefit of taking up much less space than the classical game it is inspired by. [gcall1979] had built himself a small game for the lounge room, but found keeping score to be a tedious exercise. Of course, that was nothing that couldn’t be solved with some electronics!

The game consists of a skeeball-type minigolf course, where the score is determined by the hole the player puts the ball through. To track this, each hole is fitted with an IR break-beam sensor that triggers when a ball passes through. Vinyl siding is used to guide the balls going through the holes to ensure the sensor is triggered consistently. The sensors are read by an Arduino Mega, which is also responsible for flashing LEDs and updating the score throughout the game on the included 7-segment displays.

It’s a basic hack, but one that makes the game far more of a self-contained experience. No more fumbling with pencils and paper means it’s easier to focus on dominating the competition on the (miniature) green. Of course, those with dreams of the driving range might consider this recreation of the famous Floating 14th Hole!

Micropython On Microcontrollers

November 14, 2020 by Bryan Cockfield 54 Comments

There are plenty of small microcontrollers available for all kinds of tasks, each one with its unique set of features and capabilities. However, not all of us want to spend time mucking about in C or assembly to learn the intricacies of each different chip. If you prefer the higher planes of Python instead, it’s not impossible to import Python on even the smallest of microcontrollers thanks to MicroPython, which [Rob] shows us in this project based on the ESP32.

[Rob] has been working on a small robot called Marty which uses an ESP32 as its brain, so the small microcontroller is already tasked with WiFi/Bluetooth communications and driving the motors in the robot. Part of the problem of getting Python to run on a platform like this is that MicroPython is designed to be essentially the only thing running on the device at any one point, but since the ESP32 is more powerful than the minimum requirements for MicroPython he wanted to see if he could run more than just Python code. He eventually settled on a “bottum-up” approach to build a library for the platform, rather than implementing MicroPython directly as a firmware image for the ESP32.

The blog post is an interesting take on running Python code on a small platform, and goes into some details with the shortcomings of MicroPython itself which [Rob] ended up working around for this project. He’s also released the source code for his work on his GitHub page. Of course, for a different approach to running Python and C on the same small processor, there are some libraries that accomplish that as well.

A Different Kind Of IKEA Hack: Javascript Price Comparison By Location

November 14, 2020 by Lewin Day 8 Comments

When looking for the best deal, it pays to shop around. When it comes to chain stores, of course, one expects the price to be the same across their retail network. However, where international companies are concerned, occasionally a better deal is just a border crossing away. To investigate the best possible price on IKEA’s flatpacked goods, [Sn0w5t0rm] whipped up a scirpt to make comparisons easy.

The hack consists of a small piece of Javascript that runs in a browser extension like Greasemonkey (Firefox) or Tampermonkey (Chrome). When visiting an IKEA product page, it shows the price of the same item in the alternative country of your choice. Often, significant savings can be had – the SKOGSTA table is €176 cheaper in the Netherlands compared to Belgium.

While the script does require some customization to suit your location, it could nonetheless save you a bundle on some home furnishings if your live near enough to a border. We’d love to see the concept taken further to tease out best prices in a given region for goods from all stores. Similar techniques can net you cheap airfares, too!

Illuminated 3D Printed Guitar Is Ready To Rock

November 14, 2020 by Tom Nardi 6 Comments

When we think of 3D printed parts for our projects, most of us imagine little bits like brackets and mounting plates. Perhaps the occasional printed project enclosure. But if you’ve got a big custom printer as [Joshendy] does, plus plenty of time, it opens up a whole new world of large scale projects. Take for example the gorgeous RGB LED guitar body he recently completed.

Despite the considerable 300 x 300 mm build area of his custom 3D printer, [Joshendy] still had to design the guitar body in sections that could be bolted together after being printed in ABS. It took around 60 hours to run off all the parts, with the large central section taking the longest to print at 28 hours. With the generous application of heat-set inserts, the assembled guitar should be plenty strong.

The white ABS of the guitar body helps diffuse the LEDs.

While the skeletal plastic body of the guitar is certainly visually interesting in itself, it only makes up for half of the final look. Inside the central cavity, [Joshendy] has embedded two strips of RGB LEDs, a 128×64 OLED screen, and a custom PCB that plays host to a STM32L4 microcontroller the appropriate voltage regulators necessary to run it all on a battery pack.

The board taps into the audio being produced by the guitar and uses a fast Fourier transform (FFT) to get the LEDs reacting to the beat. As demonstrated in the video after the break, you can use the screen to navigate through the different lighting modes in real-time right on the instrument itself.

We covered the equally impressive large-format 3D printer that [Joshendy] used to produce this guitar earlier in the month, and it’s quite exciting to see the sort of things he’s printing on it already. This project has already set the bar very high, and we can’t wait to see what he comes up with next.

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MicroOS Is Immutable Linux

November 14, 2020 by Al Williams 41 Comments

Linux finds a lot of uses in computers that aren’t desktops. But there is a problem. What happens if your mission-critical control computer or retail kiosk gets an update and then fails? Happens all the time with Windows and it can happen with Linux, too. The openSUSE project has an answer: MicroOS which bills itself as immutable. Aimed at container deployment, the operating system promises atomic updates with no disk changes during runtime. If an update does break something, the BTRFS file system allows you to roll back to a previous snapshot. [Tyler] installs the OS and gives it a walkthrough in the video below.

As [Tyler] found, there are not many applications installed by default. Instead, you are expected to install flatpaks so the applications live in their own containers, isolated from the operating system and each other.

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What Is Worth Saving?

November 14, 2020 by Elliot Williams 72 Comments

When it rain, it pours. One of the primary support cables holding up the Arecibo Observatory dish in Puerto Rico has just snapped, leaving its already uncertain fate. It had been badly damaged by Hurricane Maria in 2017, and after a few years of fundraising, the repairs were just about to begin on fixing up that damage, when the cable broke. Because the remaining cables are now holding increased weight, humans aren’t allowed to work on the dome until the risk of catastrophic failure has been ruled out — they’re doing inspection by drone.

Arecibo Observatory has had quite a run. It started out life as part of a Cold War era ICBM-tracking radar, which explains why it can transmit as well as receive. And it was the largest transmitting dish the world had. It was used in SETI, provided the first clues of gravitational waves, and found the first repeating fast radio bursts. Its radar capabilities mean that it could be used in asteroid detection. There are a number of reasons, not the least of which its historic import, to keep it running.

So when we ran this story, many commenters, fearing the worst, wrote in with their condolences. But some wrote in with outrage at the possibility that it might not be repaired. The usual suspects popped up: failure to spend enough on science, or on infrastructure. From the sidelines, however, and probably until further structural studies are done, we have no idea how much a repair of Arecibo will cost. After that, we have to decide if it’s worth it.

Per a 2018 grant, the NSF was splitting the $20 M repair and maintenance bill with a consortium led by the University of Central Florida that will administer the site. With further damage, that might be an underestimate, but we don’t know how much of one yet.

When do you decide to pull the plug on something like this? Although the biggest, Arecibo isn’t the only transmitter out there. The next largest transmitters are part of Deep Space Network, though, and are busy keeping touch with spacecraft all around our solar system. For pure receiving, China’s FAST is bigger and better. And certainly, we’ve learned a lot about radio telescopes since Arecibo was designed.

I’m not saying that we won’t shed a tear if Arecibo doesn’t get repaired, but it’s not the case that the NSF’s budget has been hit dramatically, or that they’re unaware of the comparative value of various big-ticket astronomy projects. Without being in their shoes, and having read through the thousands of competing grant proposals, it’s hard to say that the money spent to prop up a 70 year old telescope wouldn’t be better spent on something else.

Turn-by-turn Smart Glasses Give You Direction

November 14, 2020 by Al Williams 22 Comments

[SamsonMarch] designs electronic products by day and — apparently — does it in his spare time, too. His latest is a pair of really cool shades that give him turn-by-turn directions as he walks around town. Unlike some smart glasses, these get around the difficult problem of building a heads-up display by using a very simple interface based on colored LEDs visible to your peripheral vision in the temples of the frames.

The glasses themselves look great; designed in Fusion 360 and cut out of wood, no one would give them a second glance. [Sam] says you could 3D print them, too, but we think the wood looks best even if the stock is a cheap bamboo cutting board. He also cut the lenses out of acrylic.

The slots in the temples are where the action is, though. An iPhone app takes input and talks to Apple services to get directions. A lot of thought went into making the app work even though the phone keeps trying to put it to sleep. Each PCB hosts an RGB LED for indicating left/right turn and destination. They talk to the app using BLE and include accelerometers which put the boards — powered by coin cells — into sleep mode when no movement is detected.

Overall a fun and good looking project. There are even covers to hide the boards during normal use. The files you need to reproduce it are on GitHub. Usually, when we see smart glasses, they have some sort of screen which is harder to do. Of course, it is impossible to avoid comparisons to Google Glass.

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