Know Audio: Get Into The Groove

The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Dydric [CC BY-SA 2.5)], via Wikimedia Commons.
The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Photo by Dydric CC-BY-SA 2.5
For me, the vinyl record player is the spiritual home of my audio listening experience, probably because I’m of the last generation to grow up when vinyl was king. The 12″ album, with its full-size sleeve and copious sleeve notes, used to be an integral part of musical enjoyment that hasn’t been adequately replicated in the age of streaming.

And like anyone who became an adult while CD players were still expensive luxury items, I started my journey into Hi-Fi with a turntable set-up that sounded pretty good. Since a new generation have in recent years rediscovered vinyl, it’s once again something that should be part of any review of audio technology.

I would have started this piece with a full run-down of the constituent parts of a good turntable, but since that’s a piece that I wrote back in 2017, it’s time to investigate some of the audiophile claims about vinyl recordings. It’s fair to say that this is an area where a lot of complete rubbish is spouted by people who should know better, and that’s something I find immensely entertaining to poke fun at. Buckle up. Continue reading “Know Audio: Get Into The Groove”

Star Trek Tap Controller, Take Two

Engineering student and DIY enthusiast [Xasin] thought that the usual ways of controlling various home devices, such as phone apps and web interfaces, were too boring. Instead, he developed the wearable Tap interface which is a cross between a Star Trek comms badge and mobile holo-emitter. The basic idea is to control stuff by tapping the pendant. But things got a little out of hand since this project started two years ago.

[Xasin] began with Tap version 1 back in 2019, and learned all about coding for BLE, making 3D printed cases, and eventually working out all the kinks in the system. Tap v1 used capacitive touch sensing, but the current version detects physical taps using an accelerometer and also can detect gestures. Feature creep along the way brings a sensor array, an array of emotive LEDs, an OLED screen, and a speaker. The whole thing is powered by a dual-core ESP32 Pico MCU. [Xasin] has published his project on GitHub in case you want to explore some of these other features on your own.

The project is only partially up and running because a few critical components are unavailable due to the global parts shortage. But it will soon be able to control smart home devices, such as [Xasin]’s standalone Dragon’s Home smart home system that we wrote about earlier this year. If you want to learn more about tap controlling in general, check out this article from 2018. You can see the Tap introduce itself and its features in the short video below the break.

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C Is The Greenest Programming Language

Have you ever wondered if there is a correlation between a computer’s energy consumption and the choice of programming languages? Well, a group of Portuguese university researchers did and set out to quantify it. Their 2017 research paper entitled Energy Efficiency across Programming Languages / How Do Energy, Time, and Memory Relate?  may have escaped your attention, as it did ours.

Abstract: This paper presents a study of the runtime, memory usage and energy consumption of twenty seven well-known soft- ware languages. We monitor the performance of such lan- guages using ten different programming problems, expressed in each of the languages. Our results show interesting find- ings, such as, slower/faster languages consuming less/more energy, and how memory usage influences energy consump- tion. We show how to use our results to provide software engineers support to decide which language to use when energy efficiency is a concern.

While we might take issue with some of the programming languages selected as being “well known”, the project was very thorough and quite well documented. Most people would take for granted that a computer program which runs faster will consume less energy. But this might not always be true, as other factors enter into the power consumption equation besides speed. The team used a collection of ten standard algorithms from the Computer Language Benchmarks Game project (formerly known as The Great Computer Language Shootout) as the basis for their evaluations.

Last year they updated the functional language results, and all the setups, benchmarks, and collected data can be found here. Check out the paper for more details. Have your choice of programming language ever been influenced by energy consumption?

What It Takes: Turning A Hatchback Into A Race Car

We’ve spoken a lot about building race cars here at Hackaday, but what does it actually look like to go out and do it? The boys from [Bad Obsession Motorsport] dived into that very question with their Bargain Racement series last year.

The CityCar Cup championship aims to keep entry costs low and racing competitive by racing cheap hatchbacks with a strict ruleset. Credit: Nankang Tyre CityCar Cup

The series follows the duo as they build a Citroen C1 into a competitive race car to take on the City Car Cup, an entry-level racing series focused on keeping the field competitive and the racing close.

Even at this level, there’s plenty to do to prep the car for competition. The rollcage needs to be installed, seats changed out for race-spec gear, and plenty of wiring to do as well. [Nik] and [Richard] have plenty of experience in the field of motorsport, and shine a great light on how to do the job, and do it right.

All in all, building the car cost £5995 pounds, starting from a used £850 Citroen C1. However, actually going racing costs more than that. Between race suits and boots, a helmet, club memberships and race entry fees, it cost a full £8273 to get to the first race. It’s steep, though much of those costs are upfront. Keep the car off the walls and year on year, you only need to keep paying for entry fees, memberships and consumables like fuel and tires.

It’s a great look at everything from building a race car, to testing and then actually competing as well. It serves as an excellent real-world example of what we talk about in our series on how to get into cars, which just recently touched on prepping a car for endurance competition. Video after the break.

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Linux: Coming Soon To M1 Macbooks

Regardless of the chipset or original intended use of any computer system, someone somewhere is going to want to try and run Linux on it. And why not? Linux is versatile and free to use as well as open-source, so it’s quite capable of running on almost anything. Of course, it takes a little while for the Linux folk to port the software to brand new hardware, but it’s virtually guaranteed that it’s only a matter of time before Linux is running on even the most locked-down of hardware, like the M1 MacBooks.

[Hector Martin] aka [marcan] has been hard at work getting Linux up and running on the latest Apple offerings with their ARM-based M1 processors. Since these are completely divorced from their x86 product line the process had to be worked from the ground up which included both booting Linux and modifying the kernel to include support for the hardware. [marcan] has a lot of hardware working such as the USB ports and the SD card slot, and notes that his setup is even compatible with the webcam notch included in the latest batch of MacBooks.

There are a few things still missing. He’s running Arch and doesn’t have the GPU configured yet, so all of the graphics are rendered in software. But he has put the computer through the wringer including running some computationally-intense software for nearly a full day before realizing that the machine wasn’t charging, which did not make much difference in performance. These machines are indeed quite capable with their new ARM chipsets and hopefully his work going forward will bring Linux to the rest of us who still use Macs even if they don’t want to run macOS.

A nixie tube next to a screenshot of a to-do list

Nixie Tube Indicator Tells You How Many Tasks You’ve Got Left To Do

For busy people, keeping track of all the tasks on your to-do list can be a daunting task in itself. Luckily there’s software to help you keep organized, but it’s always nice to have a physical artifact as well. Inspired by some beautiful nixie clock designs, [Bertrand Fan] decided to build a nixie indicator that tells him how many open items are on his to-do list, giving a shot of instant gratification as it counts down with each finished task.

The task-management part of this project is a on-line tool called Todoist. This program comes with a useful Web API that allows you to connect it your own software projects and exchange data. [Bert] wrote some code to extract the number of outstanding tasks from his to-do list and send it to an ESP8266 D1 Mini that drives the nixie tube. Mindful of the security implications of letting such a device connect directly to the internet, he set up a Mac Mini to act as a gateway, connecting to the ESP8266 through WiFi and to the Todoist servers through a VPN.

The little ESP board is sitting in a 3D-printed case, together with the nixie driver circuits and a socket to hold the tube. A ceramic tile glued to the front gives it a bit more of a sturdy, luxury feel to match the shiny glass and metal display device. The limitations of the nixie tube restrict the number of tasks indicated to nine, but we imagine this might actually be useful to help prevent [Bert] from overloading himself with too many tasks. After all, what’s the point of having this device if you can’t reach that satisfying “zero” at the end of the day?

Although nowadays nixie tubes are mostly associated with fancy clocks, we’ve seen them used in a variety of other uses, such as keeping track of 3D-printer filament, adding a display to a 1940s radio, or simply displaying nothing useful at all.

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Finally, A Piano BBQ Grill That You Can Drive Around The Workshop

It’s a truth universally acknowledged that sometimes a little music can add much to a nice afternoon picnic. It’s also well-known that meat cooked over hot coals should be turned regularly to allow for even cooking. This barbecue grille project from [Handy Geng] delivers on both counts.

The project uses a full 88 motors, activated by pressing keys on an electronic piano. The technique used is simple; rather than interface with the keyboard electronically or over MIDI, instead, a microswitch is installed under each individual key.

Thus, when the piano keys are pressed, the corresponding motors are switched on. Each motor turns a skewer loaded with meat, sitting above a box of hot coals. Thus, playing the piano turns the meat, allowing it to be cooked on all sides without burning.

As a further bonus, the entire piano barbecue grille is also motorized, allowing [Handy Geng] to do laps around his workshop while playing the piano and cooking up lunch. It’s a great way to cook up some grilled kebabs while simultaneously entertaining one’s guests.

We’ve seen some other fun grill hacks too – even robotic ones! Video after the break.

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