Author: Jenny List

2982 Articles

Piezo Buzzer Makes A Drum

January 15, 2025 by 6 Comments

The humble piezo disc buzzer is much more than something that makes tinny beeps in retro electronic equipment, it can also be used as a sensor. Tapping a piezo buzzer gives an interesting waveform, with a voltage spike followed by an envelope, and then a negative rebound voltage. It’s something [Igor Brichkov] is using, to make a simple but effective electronic drum.

First of all, the output of the buzzer must be tamed, which he does by giving it a little impedance to dissipate any voltage spikes. There follows some simple signal conditioning with passive components, to arrive at an envelope for the final drum sound. How to turn a voltage into a sound? Using a voltage controlled amplifier working on a noise source. The result is recognizably the drum sound, entirely in electronics.

In a world of digital music it’s easy to forget the simpler end of sound synthesis, using circuits rather than software. If you hanker for the Good Old Days, we have an entire series on logic noise, doing the job with 4000 series CMOS logic.

Continue reading “Piezo Buzzer Makes A Drum” →

A Direct Conversion Receiver Anyone Can Build

January 15, 2025 by 14 Comments

A couple of years ago one of the Hackaday Prize finalists was a project to take highschoolers through building a direct conversion radio receiver for the 40 metre amateur band. It was originated by the SolderSmoke podcast, and we’re pleased to see that they’ve recently put up an overview video taking the viewer through the whole project in detail.

It’s a modular design, with all the constituent building blocks broken out into separate boards on which the circuitry is built Manhattan style. Direct conversion receivers are pretty simple, so that leaves us with only four modules for oscillator, bandpass filter, mixer, and audio amplifier. We particularly like that it’s permeability tuned using a brass screw and an inductor, to make up for the once-ubiquitous variable capacitors now being largely a thing of the past.

A point that resonated was that most radio amateurs never make something like this. Arguments can be made about off-the-shelf rigs and chequebook amateurs, but we’d like to suggest that everyone can benefit from a feel for analogue circuitry even if they rarely have a need for a little receiver like this one. We like this radio, and we hope you will too after seeing the video below the break.

Need reminding? See the Hackaday.io project page, and the Hackaday Prize finalists from that year.

Continue reading “A Direct Conversion Receiver Anyone Can Build” →

It’s A Doughnut, In Hardware

January 14, 2025 by 6 Comments

Making a physical doughnut is easy enough, given a good dough recipe and a nice hot deep fat fryer. But have you ever considered making a one in physical electronic hardware, on an ASIC? [A1k0n] has, at least in terms of making a virtual doughnut. It’s a hardware implementation of a ray tracer which renders a rotating doughnut to a VGA screen, and it comes courtesy of around 7000 logic cells on the latest iteration of Tiny Tapeout.

We will not pretend to be mathematical or ray tracing experts here at Hackaday so we won’t presume to explain in detail the circuitry, suffice to say that the clever hack here lies in a method using only shift and add operations rather than the complex trigonometry we might expect. It uses a slightly esoteric VGA mode to work with the device clock, so while CRT monitors have no problems it can have artifacts on an LCD. The full explanation goes into great detail, for the math heads among you.

We’ve reported on quite a few Tiny Tapeout projects over the years, as the many-ASICs-on-a-chip extends its capabilities.

It’s A Bench, But It’s Not Benchy

January 12, 2025 by 27 Comments

Whatever the nuances are surrounding the reported taking down of remixes derived from the famous Benchy 3D printer stress test, it was inevitable that in its aftermath there would be competing stress tests appear under more permissive licensing. And so it has come to pass, in the form of [Depep1]’s Boaty, a model that’s not a boat, but a bench. Sadly this is being written away from a 3D printer so we can’t try it, but we can immediately see that its low bed contact area from having spindly legs would be a significant test for many printers’ bed adhesion, and it has overhangs and bridges aplenty.

It’s always interesting to see new takes on a printer stress test, after all we can all use something to check the health of our machines. But the Benchy saga isn’t something we think should drive you away from the little boat we know and love, as it remains an open-source model as it always has been. We don’t know the exact reasons why the derivatives were removed, but we understand from Internet scuttlebut that the waters may be a little more cloudy than at first supposed. If there’s any moral at all to the story, it lies in reading and understanding open source licences, rather than just assuming they all allow us to do anything we want.

Meanwhile it’s likely this model will be joined by others, and we welcome that. After all, innovation should be part of what open source does.

Missed the Benchy takedown story? Catch up here.

Thanks [Jeremy G] for the tip.

Tactility; The ESP32 Gets Another OS

January 11, 2025 by 11 Comments

Doing the rounds this week is a new operating system for ESP32 microcontrollers, it’s called Tactility, and it comes from [Ken Van Hoeylandt]. It provides a basic operating system level with the ability to run apps from an SD card, and it has the choice of a headless version or an LVGL-based touch UI.

Supported devices so far are some Lillygo and M5Stack boards, with intriguingly, support in the works for the Cheap Yellow Display board that’s caught some attention recently. The term “ESP32” is now a wide one encompassing Tensilica and RISC-V cores and a range of capabilities, so time will tell how flexible it is for all branches of the family.

We find this OS to be interesting, both in its own right and because it joins at least two others trying to do the same thing. There’s [Sprite_TM]’s PocketSprite mini console, and the operating system used by the series of Netherlands hacker camp badges,  We’ll be trying to get a device running it, in order to give you a look at whether it’s suitable for your projects. If it runs well on the cheaper hardware, it could be a winner!

Hackaday Podcast Episode 303: The Cheap Yellow Display, Self-Driving Under $1000, And Don’t Remix That Benchy

January 10, 2025 by 1 Comment

As the holiday party season fades away into memory and we get into the swing of the new year, Elliot Williams is joined on the Hackaday Podcast by Jenny List for a roundup of what’s cool in the world of Hackaday. In the news this week, who read the small print and noticed that Benchy has a non-commercial licence? As the takedown notices for Benchy derivatives fly around, we muse about the different interpretations of open source, and remind listeners to pay attention when they choose how to release their work.

The week gave us enough hacks to get our teeth into, with Elliot descending into the rabbit hole of switch debouncing, and Jenny waxing lyrical over a crystal oscillator. Adding self-driving capability to a 30-year-old Volvo caught our attention too, as did the intriguing Cheap Yellow Display, an ESP32 module that has (almost) everything. Meanwhile in the quick hacks, a chess engine written for a processor architecture implemented entirely in regular expressions impressed us a lot, as did the feat of sending TOSLINK across London over commercial fibre networks. Enjoy the episode, and see you again next week!

Continue reading “Hackaday Podcast Episode 303: The Cheap Yellow Display, Self-Driving Under $1000, And Don’t Remix That Benchy” →

SerenityOS On Real Hardware

January 10, 2025 by 8 Comments

One of the problems facing any developer working on their own operating system is that of hardware support. With many thousands of peripherals and components that can be found in a modern computer, keeping up requires either the commercial resources of Microsoft or the huge community of Linux.

For a small project such as SerenityOS this becomes a difficult task, and for that reason the primary way to run that OS has always been in an emulator. [Sdomi] however has other ideas, and has put a lot of effort to getting the OS to run on some real hardware. The path to that final picture of a laptop with a SerenityOS desktop is long, but it makes for a fascinating read.

The hardware in question is an Intel powered Dell Chromebook. An odd choice you might think, but they’re cheap and readily available, and they have some useful debugging abilities built in. We’re treated to an exploration of the hardware and finding those debug ports, and since the USB debugging doesn’t work, a Pi Pico clone is squeezed into the case. We like that it’s wired up to the flash chip as well as serial.

Getting access to the serial port from the software turned out to be something of a pain, because the emulated UART wasn’t on the port you’d expect. Though it’s an Intel machine it’s not a PC clone, so it has no need. Some epic hackery involving rerouting serial to the PC debug port ensued, enabling work to start on an MMC driver for the platform. The eventual result is a very exclusive laptop, maybe the only one running SerenityOS on hardware.

We like this OS, and we hope this work will lead to it becoming usable on more platforms. We took a look at it back in 2023, and it’s good to hear that it’s moving forward.