Logic Analyzers: Capabilities And Limitations

September 12, 2023 by Arya Voronova 12 Comments

Last time, we’ve used a logic analyzer to investigate the ID_SD and ID_SC pins on a Raspberry Pi, which turned out to be regular I2C, and then we hacked hotplug into the Raspberry Pi camera code with an external MCU. Such an exercise makes logic analyzers look easy, and that’s because they are! If you have a logic analyzer, you’ll find that a whole bunch of hacks become available to you.

In this article, let’s figure out places where you can use a logic analyzer, and places where you can’t. We’ll start with the first limitation of logic analyzers – capture speed. For instance, here’s a cool thing you can buy on Aliexpress – a wristband from TTGO that looks like a usual fitness tracker, but has an ESP32 in it, together with an IMU, an RTC, and an IPS screen! The seller also has an FFC-connectable devboard for programming this wristband over UART, plus vibromotor and heartrate sensor expansion modules.

You can run C, MicroPython, Rust, JavaScript, or whatever else – just remember to bring your own power saving, because the battery is super small. I intended to run MicroPython on it, however, and have stumbled upon a problem – the ST7735-controller display just wouldn’t work with the st7735.py library I found; my image would be misaligned and inverted.

The specifications didn’t provide much other than “ST7735, 80×160”. Recap – the original code uses an Arduino (C++) ST7735 library and works well, and we have a MicroPython ST7735 library that doesn’t. In addition to that, I was having trouble getting a generic Arduino ST7735 library to work, too. Usually, such a problem is caused by the initialization commands being slightly different, and the reason for that is simple – ST7735 is just the name of the controller IC used on the LCD panel.

Each display in existence has specifics that go beyond the controller – the pixels of the panel could be wired up to the controller in a bunch of different ways, with varying offsets and connection types, and the panel might need different LCD charge pump requirements – say, depending on the panel’s properties, you might need to write 0x10 into a certain register of the ST7735, or you will need 0x40. Get one or more of these registers wrong, and you’ll end up with a misaligned image on your display at best, or no output at worst. Continue reading “Logic Analyzers: Capabilities And Limitations” →

Wi-Fi 7: The Next Big Leap Or A Whole Lotta Nothing?

September 11, 2023 by Lewin Day 52 Comments

For most people, the Wi-Fi hardware of today provides a perfectly satisfactory user experience. However, technology is ever-evolving, and as always, the next advancement is already around the corner. Enter Wi-Fi 7: a new standard that is set to redefine the boundaries of speed, efficiency, and connection reliability.

Wi-Fi 7 isn’t just another incremental step in the world of wireless tech. It’s promising drastic improvements over its predecessors. But what does it bring to the table? And how does it differ from Wi-Fi 6E, which is still relatively fresh in the market? Read on.

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Where Did Electronic Music Start?

September 7, 2023 by Jenny List 53 Comments

A culture in which it’s fair to say the community which Hackaday serves is steeped in, is electronic music. Within these pages you’ll find plenty of synthesisers, chiptune players, and other projects devoted to synthetic sound. Not everyone here is a musician of obsessive listener, but if Hackaday had a soundtrack album we’re guessing it would be electronic. Along the way, many of us have picked up an appreciation for the history of electronic music, whether it’s EDM from the 1990s, 8-bit SID chiptunes, or further back to figures such as Wendy Carlos, Gershon Kingsley, or Delia Derbyshire. But for all that, the origin of electronic music is frustratingly difficult to pin down. Is it characterised by the instruments alone, or does it have something more specific in the music itself? Here follows the result of a few months’ idle self-enlightenment as we try to get tot he bottom of it all.

Will The Real Electronic Music Please Stand Up?

Page from the Telharmonium patent, showing the tone wheels — If you own a synthesiser, the Telharmonium is its daddy.

Anyone reading around the subject soon discovers that there are several different facets to synthesised music which are collectively brought together under the same banner and which at times are all claimed individually to be the purest form of the art. Further to that it rapidly becomes obvious when studying the origins of the technology, that purely electronic and electromechanical music are also two sides of the same coin. Is music electronic when it uses an electronic instrument, when electronics are used to modify the sound of an acoustic instrument, when it is sequenced electronically often in a manner unplayable by a human, or when it uses sampled sounds? Is an electric guitar making electronic music when played through an effects pedal?

The history of electronic music as far as it seems from here, starts around the turn of the twentieth century, and though the work of many different engineers and musicians could be cited at its source there are three inventions which stand out. Thaddeus Cahill’s tone-wheel-based Telharmonium US patent was granted in 1897, the same year as that for Edwin S. Votey’s Pianola player piano, while the Russian Lev Termen’s Theremin was invented in 1919. In those three inventions we find the progenital ancestors of all synthesisers, sequencers, and purely electronic instruments. If it appears we’ve made a glaring omission by not mentioning inventions such as the phonograph, it’s because they were invented not to make music but to record it. Continue reading “Where Did Electronic Music Start?” →

Mining And Refining: Quartz, Both Natural And Synthetic

September 6, 2023 by Dan Maloney 17 Comments

So far in this series, pretty much every material we’ve covered has had to undergo a significant industrial process to transform it from its natural state to a more useful product. Whether it’s the transformation of bauxite from reddish-brown clay to lustrous aluminum ingots, or squeezing solid sulfur out of oil and natural gas, there haven’t been many examples of commercially useful materials that are taken from the Earth and used in their natural state.

Quartz, though, is at least a partial exception to this rule. Once its unusual electrical properties were understood, crystalline quartz was sent directly from quarries and mines to factories, where they were turned into piezoelectric devices with no chemical transformation whatsoever. The magic of crystal formation had already been done by natural processes; all that was needed was a little slicing and dicing.

As it turns out, though, quartz is so immensely useful for a technological society that there’s no way for the supply of naturally formed crystals to match demand. Like copper before it, which was first discovered in natural metallic deposits that could be fashioned into tools and decorations more or less directly, we would need to discover different sources for quartz and invent chemical transformations to create our own crystals, taking cues from Mother Nature’s recipe book on the way.

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You’ve Got Mail: Straining The Limits Of Machine And Man

September 5, 2023 by Kristina Panos 10 Comments

When we last left this subject, I told you all about Transorma, the first letter-sorting machine in semi-wide use. But before and since Transorma, machines have come about to perform various tasks on jumbled messes of mail — things like distinguishing letters from packages, making sure letters are all facing the same way before cancelling the postage, and the gargantuan task of getting huge piles of mail into the machines in the first place. So let’s dive right in, shall we?

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On Vim, Modal Interfaces And The Way We Interact With Computers

September 1, 2023 by Maya Posch 65 Comments

The ways in which we interact with computers has changed dramatically over the decades. From flipping switches on the control panels of room-sized computers, to punching holes into cards, to ultimately the most common ways that we interact with computers today, in the form of keyboards, mice and touch screens. The latter two especially were developed as a way to interact with graphical user interfaces (GUI) in an intuitive way, but keyboards remain the only reasonable way to quickly enter large amounts of text, which raises many ergonomic questions about how to interact with the rest of the user interface, whether this is a command line or a GUI.

For text editors, perhaps the most divisive feature is that of modal versus non-modal interaction. This one point alone underlies most of the Great Editor War that has raged since time immemorial. Practically, this is mostly about highly opiniated people arguing about whether they like Emacs or vi (or Vim) better. Since in August of 2023 we said our final farewell to the creator of Vim – Bram Moolenaar – this might be a good point to put down the torches and pitchforks and take a sober look at why Vim really is the logical choice for fast, ergonomic coding and editing.

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Copper Be Gone: The Chemistry Behind PCB Etching

August 31, 2023 by Dan Maloney 37 Comments

For a lot of reasons, home etching of PCBs is somewhat of a dying art. The main reason is the rise of quick-turn PCB fabrication services, of course; when you can send your Gerbers off and receive back a box with a dozen or so professionally made PCBs for a couple of bucks, why would you want to mess with etching your own?

Convenience and cost aside, there are a ton of valid reasons to spin up your own boards, ranging from not having to wait for shipping to just wanting to control the process yourself. Whichever camp you’re in, though, it pays to know what’s going on when your plain copper-clad board, adorned with your precious artwork, slips into the etching tank and becomes a printed circuit board. What exactly is going on in there to remove the copper? And how does the etching method affect the final product? Let’s take a look at a few of the more popular etching methods to understand the chemistry behind your boards.

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