Day: April 9, 2020

A Fantastic Raspberry Pi Handheld Just Got Better

April 9, 2020 by 23 Comments

Last year, we brought you word of the MutantC by [rahmanshaber]. The Raspberry Pi handheld was more than a little inspired by the classic T-Mobile Sidekick, with a sliding display and physical QWERTY keyboard. The design was a little rough around the edges and missing a few key features, but it was clear the project had a lot of potential.

Today, we’re happy to report that [rahmanshaber] has officially released MutantC_v2. It looks like the new version of this handheld, perhaps more properly categorized as a ultra-mobile PC (UMPC), successfully addresses a number of the shortcomings found in the original; so if you held off on building one last year, you might want to start warming up the 3D printer now.

The major improvement over the original is the inclusion of a battery, which makes the device truly mobile. This was something that we mentioned [rahmanshaber] was working on back when he released the first version, as it was easily the most requested feature from the community. We certainly wouldn’t say a miniature handheld computer is completely useless if it has to stay tethered, but there’s no arguing that being able to take it on the go is ideal.

This upgraded version of the design now officially supports the Raspberry Pi 4 as well, which previously [rahmanshaber] was advising against due to overheating concerns. Slotting in the latest-and-greatest edition of every hacker’s favorite Linux single board computer will definitely kick things up a notch, though we imagine the older and less power hungry iterations of the Pi will be plenty for the sort of tasks you’re likely to be doing on a gadget like this.

If you like the idea of having a diminutive Linux computer within arm’s reach of your bench but aren’t necessarily committed enough to build something like the MutantC, there are certainly simpler designs you can get started with.

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Controlling A Building Sized Pipe Organ With Midi

April 9, 2020 by 13 Comments

Musical instruments come in all shapes and sizes. For sheer scale and complexity though, you can’t beat pipe organs. [Rob Scallon] visited the Fourth Presbyterian Church in Chicago to look at their massive pipe organ which boasts over 8000 individual pipes. He also discovered that it has a MIDI interface, and off course hooked up his laptop to play the Mario Bros theme song.

This organ is actually the third one the church has had, and was completed in 2016. Its capabilities are impressive, but the engineering side of it is what really blew us away. Every pipe is unique to allow it to recreate the sound of almost an entire orchestra, and the “control station” looks a bit like the cockpit of modern airliner in terms of complexity. The organ covers multiple stories across multiple parts of the church and every single pipe and part needs to be accessible for tuning and maintenance, which is almost a full time job. Check out the first video after the break for a full demonstration and tour of this incredible machine by [John Sherer], the church’s music director and organist.

The second video after the break goes through the process of hooking up a laptop to the organ after getting a technician to completely wire up the MIDI interface. They go full music geek as they marry ancient and modern music technology. [Rob] says it multiple times, and we have to believe that you need to be in the building to truly experience the sound. Let us know in the comments if any readers have heard this organ in person.

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Tell Time Like It’s 1960 With This All-Transistor Digital Clock

April 9, 2020 by 44 Comments

When you’ve got time on your hands, doing something the hard way can be therapeutic. Not that the present situation and the abundance of free time that many are experiencing has anything to do with [Leo Fernekes] all-transistor digital clock build, which he started a year ago with his students. But if you’ve got time to burn, this might be a good way to do it.

[Leo] says one of his design goals with this clock was to do it with the technology commercially available in 1960, which means relying completely on discrete components. And he and his students managed to do just that, with the exception of the seven-segment displays, which were built from the LED filaments from some modern light bulbs. Everything else, though, is as old school as it gets, and really underscores all the complexity that gets abstracted away from timekeeping with modern chips. The video below covers each module in detail, from the Schmitt trigger that cleans up the 50-Hz line frequency to the ring counters and diode matrices used to drive the display. We found the analog stair step dividers used to bring the line frequency down to a more usable pulse train particularly interesting. That clever bit of engineering saved 10 transistors over what would be required for traditional flip-flop dividers.

There’s a lot to learn from this design, and the execution is great too – we’re suckers for Manhattan-style builds, of course. Hats off to [Leo] and his lucky students on a great build.

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The Evolution Of A 3D Printed Off-Road R/C Car

April 9, 2020 by 13 Comments

For about as long as hackers and makers have been using desktop 3D printers, there have been critics that say the plastic parts they produce aren’t good for much else than toys and decorative pieces. They claim that printed parts are far too fragile to be of any practical use, and are better suited as prototype placeholders until the real parts can be injection molded or milled. Sure. Try telling that to [Engineering Nonsense].

He recently wrote in (as did a few other people, incidentally) to share the latest version of his incredible 3D printed remote control car, and seeing it tearing around in the video after the break, “fragile” certainly isn’t a word we’d use to describe it. Though it didn’t get that way overnight. The Tarmo4 represents a year of development, and as the name suggests, is the fourth version of the design.

We know the purists out there will complain that the car isn’t entirely 3D printed, but honestly, it’s hard to imagine you could get much closer than this. Outside of the electronics, fasteners, tires, and shocks, the Tarmo4 is all plastic. That includes the gearbox and drive shafts. [Engineering Nonsense] even mentions in the video that he’s not happy with the tires he’s found on the market, and that they too will likely get replaced with printed versions in the future.

While the car is certainly an incredible technical achievement, what’s perhaps just as impressive is the community that’s developed around it in such a relatively short time. Towards the end of the video he shows off a number of custom builds based on previous iterations of the Tarmo. We’re sure that interest from the community has played a part in pushing the design forward, and it’s always good to see a one-off project become something bigger. Hopefully we’ll be seeing even more from this passionate community in the near future.

Just like the Open R/C Project, Tarmo proves that 3D printed parts are more than a novelty. If these diminutive powerhouses can run with printed gears and drive shafts, then you shouldn’t have anything to worry about when you run off the parts for your next project.

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A Gambler’s Bottle Opener

April 9, 2020 by 11 Comments

People can certainly become creative when it comes to completing simple tasks like that of removing a bottle cap. Woodworker [Matt Thompson] has come up with a next-level bottle opener that not only does the job but also functions as a game of chance. (Video, embedded below.)

The process usually starts with a spin of his chore wheel that will surprisingly often advise you to drink a beer. While the bottle cap is removed by a standard wall-mounted opener, the fun starts when the cap falls through a wooden labyrinth of various mechanisms reminiscent of a Rube Goldberg machine. Finally, the cap goes through an arrangement of nails, known as a Galton Board which is also found in some pinball and historic gaming machines, before landing in one of two containers marked “winner” and “try again”. The former will trigger the rotating wheel of a self-built peanut dispenser to provide the thirsty person with some tasty snacks. While we would love to see a making-of video with more technical details of this project, we still appreciate the exquisite woodworking and fine craftsmanship that went into building it.

By the way, if you are ever in need of an Arduino board that can also serve as a bottle opener then have a look at HaDuino.

[Thanks to Emanuel for pointing out the proper name of the Galton Board]

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No Windshield? No Problem, Says McLaren

April 9, 2020 by 79 Comments

All the best sports cars look like they’re moving when they’re just sitting there, and the lines on McLaren’s newest limited-edition plaything redefine that look of speed standing still. Maybe it’s the sneering headlights or the streamlined, reverse-1966 Batmobile styling. Whatever it is, the 804-horsepower two-seater project Elva looks like it’s leaping off the line into the future.

But this future is free from the last thing we’d expect to see removed from any vehicle, especially a $1.7 million supercar — the windshield. Now that the headphone jack has been deemed expendable, it seems that nothing is sacred. The Elva is already a permanent convertible with no windows.

Though McLaren didn’t start this weird and windowless fire, the Elva is meant to fan the flames of futurism. She joins the ranks of a few windshield-free models from Ferrari, Mercedes-Benz, and Aston Martin. In the other guy’s cars, you’ll need a helmet above 30MPH unless you love the thunderous sounds of air buffeting and blown-out hair. It’s a young idea with a few bugs to work out.

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Ultrasonic Sensor Helps You Enforce Social Distancing

April 9, 2020 by 22 Comments

If you’re going outside (only for essential grocery runs, we hope) and you’re having trouble measuring the whole six feet apart from other people deal by eye, then [Guido Bonelli] has a solution for you. With a standard old HC-SR04 ultrasonic sensor, an audio module and a servo to drive a custom gauge needle he’s made a device which can warn people around you if they’re too close for comfort.

As simple as this project may sound like for anyone who has a bunch of these little Arduino-compatible modules lying around and has probably made something similar to this in their spare time, there’s one key component that gives it an extra bit of polish. [Guido] found out how intermittent the reliability of the ultrasonic sensor was and came up with a clever way to smooth out its output in order to get more accurate readings from it, using a bubble sort algorithm with a twist. Thirteen data points are collected from the sensor, then they are sorted in order to find a temporal middle point, and the three data points at the center of that sort get averaged into the final output. Maybe not necessarily something with scientific accuracy, but exactly the kind of workaround we expect around these parts!

Projects like these to help us enforce measures to slow the spread of the virus are probably a good bet to keep ourselves busy tinkering in our labs, like these sunglasses which help you remember not to touch your face. Make sure to check out this one in action after the break!

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