A child in a red shirt and blue pants balances on a board suspended across two small, green sawhorses. An astroturf hill and blue elephant-esque cart are in the background.

Popup Playground Roams Around

February 4, 2024 by Navarre Bartz 4 Comments

Going to the park is a time-honored pastime for kids around the world, but what if there isn’t one nearby? COMPA Teatro Trono and the International Design Clinic have designed a park that can come to you.

Working with a group of design students from Bolivia and America, the theatre troupe has iteratively designed a set of playground carts that can be deployed for kids to meet each other and play. El Alto, the city of 1 million where the playground plies the streets, has grown exponentially since its incorporation as an independent town in 1985. Infrastructure has trouble catching up with population jumps of 54% like that experienced from 2000-2010.

Starting with interviews with kids from the city about what was important for a playground, they found a trend of trees, slides, and the color green. Over the course of three summers, the design students went from janky prototypes to the more refined carts now seen roaming El Alto built around the idea of “exaggerated topography.” An elephant and “astroturf bee” are the two hand carts which disassemble into a variety of playground equipment once in place at a destination.

Not a ton of details are given in the article about the construction of the carts themselves, but we think this tactical urbanist approach to parks is a hack in itself. That said, be sure to point us toward some more info on the builds if you’ve found any. Know of another hack, that brings joy to your own neighborhoods? Send it to the tipsline!

Lego Guitar Is Really An Ultrasonically-Controlled Synth

January 26, 2023 by Lewin Day 4 Comments

The phrase “Lego Guitar” can be a stressful one to hear. You might imagine the idea of strings under tension and a subsequently exploding cloud of plastic shrapnel. This build from the [Brick Experiment Channel] eschews all that, thankfully, and is instead a digital synth that only emulates a guitar in its rough form factor.

The heart of the build is a Lego Mindstorms EV3 controller. It’s acts as the “body” of the guitar, and is fitted with a Lego “fretboard” of sorts. A slide is moved up and down the fretboard by the player. The EV3 controller detects the position of the slide via an ultrasonic sensor, and uses this to determine the fret the user is trying to play. The button the user presses on the controller then determines which of five “strings” the user is playing, and the selected note is sounded out from the EV3’s internal speaker. It’s strictly a monophonic instrument, but three different sounds are available: a bass guitar, a rock guitar, and a solo guitar, with all the fidelity and timbre of a 90s Casio keyboard.

It’s a fun and silly instrument, and also kind of difficult to play. The slide mechanism doesn’t offer much feedback, nor are the EV3 buttons intended for dynamic musical performance. Regardless, the player belts out some basic tunes to demonstrate the concept. We doubt you’d ever be able to play Through The Fire and Flames on such a limited instrument, but [Brick Experiment Channel] used their editing skills to explore what that might sound like regardless.

We’ve seen some other great synth guitars before, too. Modern microcontrollers and electronics give makers all kinds of creative ways to build electronic instruments with unique and compelling interfaces. Some are more successful than others, but they’re all fun to explore. Video after the break.

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Bass Guitar Gets Shapeshifting Pickups

December 5, 2021 by Bryan Cockfield 19 Comments

Electric guitars were the hip new thing back in the mid-century. The electrification of the common and portable guitar opened up a lot of avenues in terms of sound and technique. Specifically, the use of the pickup, an electromagnetic device which converts the vibrations of the guitar strings into electrical signals, increased the number of ways that a musician can alter the guitar’s sound on-the-fly. Some guitars have several rows of pickups which can be used in any number of ways, but this custom guitar has a single pickup which can be moved around the guitar’s body instead.

[Breno] was gifted this Dolphin bass guitar to start learning after years of playing a regular guitar, and while they aren’t known for high-quality instruments this guitar seemed to play and sound well enough to attempt this modification. First, a hole had to be cut all the way through the guitar’s body in order to accommodate the build. The pickup for this guitar is then mounted on two rods which allow it to move in various positions along the strings, and a second set of adjustments can be made to bring the pickups closer or further away from the strings. Some additional custom circuitry was added to control it and also to handle the volume and tone knobs, and while this was being added [Breno] and his friend [Arthur] decided this would be a great time to build some effects into the guitar’s now-custom electronics as well.

While this was largely a project for [Breno] to understand in greater depth the effect of moving the pickups around an electric guitar, the finished product looks ready to play some live shows. The addition of some extras like the effects really adds some punch to this guitar and it looks to be completely original. The nearest thing we could find is this guitar which uses hot-swappable pickups but even those are mounted in fixed locations.

A High-Speed Slide Scanner Build

April 21, 2019 by Lewin Day 19 Comments

Photographic slides were popular in the middle part of the 20th century, but are long forgotten now. If you’ve found a handful in a dusty attic, you might consider sending them away to be digitized professionally, or using a flatbed scanner at home. [Bryan Howard] found himself with over 200,000 slides, however, so that just wouldn’t do. Instead, he endeavored to build an automated scanner of his own.

Like many similar projects, [Bryan] started with an existing slide projector as a base. This means that all the difficult work of slide transport is already taken care of. The projector has then been upgraded with an LED light source and other tweaks befitting its new role. An Arduino Pro Micro runs the show, firing off the camera to image each slide before loading the next one into place. The DSLR responsible for imaging is then hooked up to a PC so the incoming images can be checked while the machine is in operation.

Preliminary tests are promising, with the scanner successfully capturing several slides in a row. [Bryan] estimates that, with a capture time of between 1 and 2 seconds per slide, it should take somewhere between 2-5 days to image the entire collection.

We wish [Bryan] the best of luck with the project, and look forward to seeing the final results. We’ve seen similar work before, too. Video after the break.

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Touchless Shop Doors Over-Engineered To A Blissful Level

March 11, 2018 by Dan Maloney 13 Comments

When [John Saunders] wanted an automatic door for his shop, rather than settle for a commercial unit, he designed and built a proximity-sensing opener to ease his passing. Sounds simple, right?

Fortunately for us, there are no half-measures at Saunders Machine Works, thanks to the multiple Tormach workcells and the people who know how to use them. The video below treats us to quite a build as a result; the first part is heavy on machining the many parts for the opener, so skip ahead to 8:33 if you’re more interested in the control electronics and programming.

The opener uses time-of-flight distance sensors and an Arduino to detect someone approaching, with a pneumatic cylinder to part a plastic strip curtain. [John] admits to more than a little scope creep with this one, which is understandable when you’ve got easy access to the tools needed to create specialized parts at will.

In the end, though, it works well for everyone but [Judd], the shop dog, and it certainly looks like it was a fun build to boot. [John]’s enthusiasm for mixing machining and electronics is infectious; check out his automated bowl feeder for assembly line use.

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Hackaday Links: July 17, 2016

July 17, 2016 by Brian Benchoff 23 Comments

There’s going to be a new Nintendo console for Christmas! It’s the NES Classic Edition. It looks like a minified NES, with weird connectors that look like the connector for the Wii Nunchuck. There are no other details.

A site called “Motherboard” reports assembling a computer is too hard and a ‘nerve-wrecking [sic]’ process. Tip of the stovepipe to the Totalbiscuit.

When I was in elementary school, the playground had a twenty foot tall metal slide that faced South. During my time there, at least three of my classmates fell off it, and I distinctly remember the school nurse’s aid running past me on the playground with a wheelchair. There wasn’t soft mulch or the weird rubber granules under this slide – just hard, compacted dirt. This slide was awesome, even if it was torn down when I was in third grade. [Brandon Hart]’s kid’s won’t look back fondly on their youth with experiences like these; he built a water-cooled slide in his backyard. He’s getting an 80°F ΔT with a trip to Ace Hardware, probably $20 in fittings, and a drill. Neat.

This is probably better suited for an ‘Ask Hackaday’ column, but [Arsenijs] has run into a bit of a problem with his Raspberry Pi Project. He’s trying to use a planarized kernel module to obfuscate the SPI bus, but he can’t do that because of a oblivated drumble pin. He could, of course, deenumerate several of the GISP modules, but this would cause a buffer underflow and eventually wreck the entire cloudstack. I told him he should use Corrosion, but he seems dead set on his Hokey implementation. If anyone has any ideas, get the glamphs and put it on the grumbo.

The Owon SDS7102 oscilloscope is a small, cheap, two-channel scope that is impressive for its price but noisier than you would expect. This scope has been thoroughly reverse engineered, and now Linux is running on this scope. This Linux scope has a working VGA display, USB host, USB device, Flash, and working Ethernet. The entire analog front end has been reversed engineered, and somehow this is now the most open oscilloscope you can buy.

The ESP32 is Espressif’s followup to their very popular ESP8266 WiFi module. The ESP32 will be much more powerful and include Bluetooth when it’s released in August. Until then, [Pighixxx] has the complete pinout for the ESP32.

Video Projector From An Old Single-slide Unit

February 24, 2011 by Mike Szczys 21 Comments

Here’s a video projector that [Matt] hacked together. He needed a small and inexpensive solution to use with his R2D2 build. As you can see in the video after the break, it has no problem playing back the Princess’ distress call. But even if R2D2 is not one of the droids you’re looking for, we think this can be useful in other ways. One use that pops into mind is for projector-based Halloween displays.

As with past projector hacks, all you really need to pull this off is a light source, an LCD screen on which you can playback video, and a lens to focus the light onto a screen. Usually the LCD is the most expensive part of the project and building an enclosure to the correct dimensions can be a bit difficult. [Matt’s] solution was to use an MP4 knockoff media player. The rest of the setup is a ’50s era slide projector. The screen from the media player is about the same size as a single film slide, so he removed the screen from the case and put it where the slides go.

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