Know Audio: Get Into The Groove

November 18, 2021 by Jenny List 62 Comments

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” →

NTP, Rust, And Arduino Make A Phenomenal Frequency Counter

November 17, 2021 by Jenny List 28 Comments

Making a microcontroller perform as a frequency counter is a relatively straightforward task involving the measurement of the time period during which a number of pulses are counted. The maximum frequency is however limited to a fraction of the microcontroller’s clock speed and the accuracy of the resulting instrument depends on that of the clock crystal so it will hardly result in the best of frequency counters. It’s something [FrankBuss] has approached with an Arduino-based counter that offloads the timing question to a host PC, and thus claims atomic accuracy due to its clock being tied to a master source via NTP. The Rust code PC-side provides continuous readings whose accuracy increases the longer it is left counting the source. The example shown reaches 20 parts per billion after several hours reading a 1 MHz source.

It’s clear that this is hardly the most convenient of frequency counters, however we can see that it could find a use for anyone intent on monitoring the long-term stability of a source, and could even be used with some kind of feedback to discipline an RF source against the NTP clock with the use of an appropriate prescaler. Its true calling might come though not in measurement but in calibration of another instrument which can be adjusted to match its reading once it has settled down. There’s surely no cheaper way to satisfy your inner frequency standard nut.

For All Their Expense, Electric Cars Are Still The Cheapest

November 16, 2021 by Jenny List 191 Comments

A criticism that we have leveled at the move from internal combustion vehicles to electric ones is that their expense can put them well beyond the range of the not-so-well-heeled motorist. Many of the electric vehicles we’ve seen thus far have been niche models marketed as luxury accessories, and thus come with a specification and list price to match. It’s interesting then to see a European report from LeasePlan looking at vehicle ownership costs which reveals that the total yearly cost of ownership (TCO) for an electric car has is now cheaper that comparable internal combustion vehicles across the whole continent in all but the fiercely competitive sub-compact segment.

TCO includes depreciation, taxes and insurance, fuel, and maintenance. Perhaps the most interesting story lies in electric cars progressing from being a high-depreciation, risky purchase to something you can sell on the second-hand market, even if they cost more up front. For example, the electric VW ID3 costs around $11,000 more than the comparable gas-powered VW Golf up front, but the higher resale price later offsets this and helps keep the TCO lower.

We’ve been following electric vehicles for a while now in the hope that an electric people’s car would surface, and have at times vented our frustration on the matter. It’s encouraging to see this particular trend as we believe it will encourage manufacturers to produce more accessible electric vehicles, especially given that we’ve just complained that driving electric seems like more of a rich man’s game.

(via Heise)

Header image: CEphoto, Uwe Aranas / CC-BY-SA-3.0.

So. What’s Up With All These Crazy Event Networks Then?

November 11, 2021 by Jenny List 21 Comments

As an itinerant Hackaday writer I am privileged to meet the people who make up our community as I travel the continent in search of the coolest gatherings. This weekend I’ve made the trek to the east of the Netherlands for the ETH0 hacker camp, in a camping hostel set in wooded countryside. Sit down, connect to the network, grab a Club-Mate, and I’m ready to go!

Forget the CTF, Connecting To WiFi Is The Real Challenge!

There no doubt comes a point in every traveling hacker’s life when a small annoyance becomes a major one and a rant boils up from within, and perhaps it’s ETH0’s misfortune that it’s at their event that something has finally boiled over. I’m speaking of course about wireless networks.

While on the road I connect to a lot of them, the normal commercial hotspots, hackerspaces, and of course at hacker camps. Connecting to a wireless network is a simple experience, with a level of security provided by WPA2 and access credentials being a password. Find the SSID, bang in the password, and you’re in. I’m as securely connected as I reasonably can be, and can get on with whatever I need to do. At hacker camps though, for some reason it never seems to be so simple.

Instead of a simple password field you are presented with a complex dialogue with a load of fields that make little sense, and someone breezily saying “Just enter hacker and hacker!” doesn’t cut it when that simply doesn’t work. When you have to publish an app just so that attendees can hook up their phones to a network, perhaps it’s time to take another look . Continue reading “So. What’s Up With All These Crazy Event Networks Then?” →

The Hackaday Remoticon 2 Badge: An Exercise In Your Own Ingenuity

November 10, 2021 by Jenny List 7 Comments

The twin challenges of the pandemic and now the semiconductor shortage have been particularly hard on the designers of event badges, as events have been cancelled and uncertain supply issues render their task impossible. When an event goes virtual, how do you even start to produce a badge for it? Make the badge and rely on enough stalwarts buying one? Or maybe produce a badge that’s a fancy take on a prototyping board?

For Hackaday Remoticon 2021, [Thomas Flummer] has produced a novel take on the second option by distributing a badge as a set of KiCAD files that can either be ordered from a PCB fab as a prototyping board or used as the canvas for a PCB to use whatever components are to hand. To demonstrate this, he’s produced an example badge that’s a MicroMod carrier.

So if you’d like to chase the full Remoticon experience with a badge there should still be enough time to order a set of boards, but to design your own electronics you’ll need to get a move on. What you might build upon it is up to you, but if you have an ESP32 module lying around you might wish to consider cloning the SHA2017 badge or its successors with the badge.team platform.

We’ve seen Thomas’ work before more than once on these pages, most notably as the man behind the BornHack badges.

NFC Performance: It’s All In The Antenna

November 10, 2021 by Jenny List 15 Comments

NFC tags are a frequent target for experimentation, whether simply by using an app on a mobile phone to interrogate or write to tags, by incorporating them in projects by means of an off-the-shelf module, or by designing a project using them from scratch. Yet they’re not always easy to get right, and can often give disappointing results. This article will attempt to demystify what is probably the most likely avenue for an NFC project to have poor performance, the pickup coil antenna in the reader itself.

The tags contain chips that are energised through the RF field that provides enough power for them to start up, at which point they can communicate with a host computer for whatever their purpose is.

“NFC” stands for “Near Field Communication”, in which data can be exchanged between physically proximate devices without their being physically connected. Both reader and tag achieve this through an antenna, which takes the form of a flat coil and a capacitor that together make a resonant tuned circuit. The reader sends out pulses of RF which is maintained once an answer is received from a card, and thus communication can be established until the card is out of the reader’s range. Continue reading “NFC Performance: It’s All In The Antenna” →

Reballing And A Steady Hand Makes A Raspberry Pi 800

November 8, 2021 by Jenny List 41 Comments

The all-in-one Raspberry Pi 400 computer is a capable device, but those seeking its maximum power may be disappointed by its 4 GB of memory. When the Pi 4 and Compute Module 4 have double that figure, surely the Pi 400 could catch up! A reddit user called [Pi800] rose to the challenge by replacing the 4 GB chip from the Pi 400 with the 8 GB chip from a Pi Compute Module, resulting in the so-called Pi 800, a working 8 GB all-in-one Pi.

As a piece of work it’s a deceptively straightforward yet extremely fiddly piece of soldering that requires a steady hand for even the most skilled of solderers. What takes it beyond the norm though is the reballing process. A ball-grid-array chip has a grid of small balls of solder on its underside that make the contacts, and these melt when it is soldered so require replacement before reworking. This is normally done with a template of carefully aligned holes to line up balls of solder in a stream of hot air, but lacking the template in this case the job was done by hand, laboriously ball by ball. A soldering task we’d hesitate to take on ourselves, so we’re impressed.

The result is an 8 GB all-in-one Pi, and it’s honestly not beyond the realms of possibility that an official version of this mod could be a future Raspberry Pi product. Perhaps we’ll wait for that, but should you be impatient then at least it’s possible to roll your own. It’s certainly not the first BGA memory swap we’ve brought you.